A little bit of everything in this weekend’s weather. We start off with summer-like heat then a series of cold fronts bring more reasonable temps and maybe some precipitation.

For Friday, look for sunny skies above and overall calm conditions. Highs will top out around the 90 degree mark. Tonight, lows dip to the mid-50s under mostly clear skies. A cold front will move through overnight cooling us down tomorrow.

Saturday continues the sunny skies but does bring some breezy winds. Highs will top out in the low 80s. Saturday night, cloud cover increases and lows dip to the mid-50s. Late night / early Sunday AM may bring a sprinkle. A second surge of cold air arrives overnight as well.

Sunday will be the most unsettled day of the period. It will be mostly cloudy and highs will reach the low 70s. There will be a chance for light showers through the morning then maybe a thunderstorm in the afternoon. Unfortunately, at this time, any precipitation that falls will likely be minimal. Have a great weekend.

An extremely eventful week in weather history showing just how varied conditions can be.  We of course see typical spring weather like tornadoes and hail but also a touch of snow and this week also marks the anniversary of the start of the Hayman Fire.

1-30

In 2012…it was the hottest June in Denver since weather records began back in 1872. The average temperature for the month was 75.0 degrees which was 7.6 degrees above normal. There were a total of seventeen 90 degree days in the month of June. The highlight of record setting month was a stretch of five consecutive 100 degree days from the 22nd to the 26th. This was only the third time in Denver weather history in which this happened. Two of the high temperatures during the stretch peaked at 105 degrees… Which set the all-time record for the month of June and tied the all-time maximum temperature for Denver.

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In 1921…heavy rainfall for nearly a week…on top of streams already swollen by mountain snowmelt…produced widespread flooding over the South Platte River basin…including the tributaries through the canyons to the west and southwest of Denver.  Heavy rainfall over the 6-day period totaled 3.36 inches in Boulder…4.98 inches in Morrison…4.27 inches in Castle Rock…and 2.94 inches in the city of Denver. Rainfall amounts in the foothills were estimated between 3 and 6 inches.  The narrow-gage tracks of the Colorado and southern railroad were destroyed in the Platte Canyon.  From the mouth of the canyon through the city to near Brighton… The river spread from 1/2 to nearly 1 1/2 miles wide… Flooding farm and pasture land and destroying or damaging many bridges.  In the city…many businesses along with as many as 500 homes were inundated…forcing their evacuation. Bridges were swept away.  The high waters flooded the rail yards and stock yards in lower downtown…closing three adjacent packing houses.  The heavy rains also caused flooding on Boulder creek in Boulder on the 6th.

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In 2004…a brief hot spell produced 3 temperature records. High temperatures of 95 degrees on the 6th and 98 degrees on the 7th were record maximum temperatures for the dates. Low temperature of 68 degrees on the 7th was a record high minimum for the date.

In 2012…severe thunderstorms broke late in the evening… Striking areas hardest from Denver southward. Locations impacted by the storms included but were not limited to: Aurora…Castle Rock…Centennial…Highlands Ranch…Lone Tree… Parker and Surrey Ridge. The storms produced a barrage of large hail…damaging straight line winds… Flash flooding and several short lived tornadoes. The hail ranged in size from 1 to 2 inches in diameter…and caused extensive damage to homes and automobiles. The hail inundated the roadways with several inches of hail in Douglas County. Consequently… Snow plows had to be called out to clear the roadways. The combination of torrential hail and heavy rain produced flash flooding in parts of Elbert…Douglas and Arapahoe counties…as thunderstorms brought up to 3.35 inches of rain to some areas within 90 minutes. In Aurora…Picadilly Road was closed from flooding north of 6th Avenue. A water rescue took place on south Gun Club Road in Arapahoe County…where floodwaters were rushing to depth of 3 feet. Flash flooding forced the closure of several streets and roads from parker south to the Pinery…where the floodwaters inundated the roadway with up to 2 feet in several locations. At Centennial Airport…a historic B-17 Flying Fortress suffered extensive damage as hailstones as large as ping pong balls struck the aircraft. Although the airframe itself did not require repair…the fabric-covered ailerons and elevators were extensively damaged. The hail came straight down and punched holes in the fabric-covered control surfaces. The aircraft landed just hours before the storm hit to participate in a weekend tour stop. Lightning also struck two homes…one in Lakewood and the other in Parker. Straight line winds downed trees and power lines in aurora. As a result…scattered electrical outages affected around five thousand residents. At Denver International Airport… 0.61 inches rainfall was recorded along with a peak wind gust of 41 mph.

In 2007…an unusually strong storm system brought very strong winds to the Front Range foothills and urban corridor. Peak gusts included:  92 mph at Boulder…85 mph…2 miles southwest of Boulder…83 mph…10 miles south of Boulder and 55 mph at Denver International Airport.  High winds forced the closure of Mt. Evans Road and Trail Ridge Road.  Several trees were uprooted across the urban corridor.  In Aurora… The driver of a car was injured when some building material blew off the Fitzsimmons complex.  The debris landed on the car and knocked the driver unconcious.  The wind forced the cancellation of 60 flights at Denver International Airport. Xcel reported outages in Boulder…Denver…Lakewood and Longmont.

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In 1904…a thunderstorm produced south winds to 40 mph with gusts to 50 mph…but only a trace of rain.

In 1942…heavy thunderstorm rainfall in south Denver caused flooding of shops…stalled motorists…and halted tramway service temporarily.  Lightning damaged houses…but there was no loss of life.  Precipitation totaled 0.53 inch in downtown Denver.

In 1951…a 24×65 foot roof of a cow barn was lifted off the building and blown to the ground by a “twister” near Fort Lupton.

In 1961…small hail and heavy rain damaged property and crops in southwest metro Denver…including the southwest section of the city…Lakewood…and Littleton.  Precipitation totaled 1.20 inch…11 miles southwest of Stapleton Airport. Complete primary and secondary rainbows were sighted by national weather service observers at Stapleton Airport.

In 1968…severe thunderstorms moving to the northeast through sections of Denver caused local flooding of streets and damage to trees and gardens from hail 1/2 to 1 3/4 inches in diameter.  One man was killed and 2 were injured at the Wellshire Golf Course when lightning struck a tree under which they had taken shelter.  At another golf course… A man was mortally injured by lightning.  Marble to golf ball size hail fell over downtown Denver.  Hail to 3/4 inch in diameter was measured in Westminster.

In 1975…hail up to 3/4 inch diameter fell in Boulder.

In 1978…a man standing under a tree on a golf course in Denver was struck in the arm by lightning.   Wind gusts to 60 mph and golf ball size hail pelted west and south Denver.

In 1986…7/8 inch hail was measured in Lafayette.

In 1990…a thin…rope-shaped tornado touched down east of the intersection of State Highway 2 and 96th avenue just north of the rocky mountain arsenal.  No damage was reported.

In 1992…a thunderstorm wind gust to 60 mph was recorded in Boulder.  A funnel cloud was sighted by a highway patrol officer just northwest of Stapleton International Airport where thunderstorm winds gusted to 51 mph.  Spotters and state patrol officers reported funnel clouds in the northwestern part of metro Denver…near Golden…and 7 miles northwest of Stapleton International Airport.

In 1993…non-convective high winds pummeled the Front Range foothills during the late morning and afternoon.  Speeds of 60 to 80 mph were common.  The winds caused several power outages as well as uprooting trees.  In Lafayette…a 4-year- old boy was slightly injured while standing on the roots of a large tree which was toppled by the winds.  The boy fell 10 feet to the ground and was bruised and scraped.  A tree fell onto a parked car in Boulder…causing about 35 hundred dollars in damage.  West wind gusts to 41 mph were recorded at Stapleton International Airport where a thunderstorm produced 1/8 inch hail at daybreak.

In 1995…severe thunderstorms produced large hail across west and north metro Denver from Golden to Westminster and Fort Lupton.  Hail ranged in size from 3/4 to 2 inches in diameter.  The largest hail fell in Fort Lupton.  A weak tornado produced a brief dust and debris cloud in a corn field 3 miles northeast of Hudson.

In 1997…two plumbers were injured…one critically…when lightning struck a pipe on which they were working in an apartment building under construction in Denver.  The bolt apparently hit one man in the hand…passed through his chest…and struck the other worker.  The critically injured man…died a few days later.  Lightning also injured a man…while he was talking on a telephone in ward.  The bolt passed through the phone line burning his ear.

In 2001…hail as large as 7/8 inch in diameter fell in Westminster.

In 2012…severe thunderstorms brought damaging wind and hail…heavy rain and flash flooding. The storms produced hail from 1.5 to 2.5 inches in diameter. In addition to the large hail…heavy rain from 1 to 2 inches also accompanied the storms. The combination of hail and heavy rain caused extensive street flooding across Aurora…Castle Rock…Centennial…Cherry Creek… Englewood…south Denver…Highlands Ranch… Lakewood and Littleton. The hail was reportedly “knee deep” in several areas making roads impassable. As a result… Snow plows had to be summoned to clear the streets. In Castle Rock…a King Soopers supermarket sustained extensive damage when roof partially collapsed under the weight of the hail. At Denver International Airport…0.61 inches of rainfall was again recorded along with a peak wind gust of 40 mph. Total property damage estimates along the Front Range for the 6th and 7th combined was 321.1 million dollars.

In 2016…large hail up to 1 inch in diameter was observed in Castle Rock.

In 2021…a landspout tornado developed in southwest Weld County…2 miles northeast of Firestone. The tornado traveled north-northeast…and ended 3 miles northwest of Platteville. The tornado reached an intensity of EF-1 on the Enhanced Fujita scale…with estimated wind speeds of 99 mph. There were no injuries…but at least two calves were killed…and several chickens. Other damage included a home located at Highway 66 and Weld County Road 21 that caught fire due to downed power lines. Downed power lines led to a closure of Weld County Road 21 between State Highway 66 and Weld County Road 32.5. The landspout was more than 10000 feet high…and could be seen by spotters as far as 40 miles away. It was on the ground for 35 minutes; it was estimated to be 50 yards wide and traveled a distance of 7.5 miles.

7-9

In 1979…rain…at times with thunder on the 7th…fell almost continuously through the morning of the 9th.  Rainfall totaled 2.28 inches at Stapleton International Airport over the 3 days.  High temperature of only 49 degrees on the 8th was a record low maximum for the date.

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In 1873…lightning struck and killed one man and damaged several houses.  The thunderstorms produced heavy rain in the city…which caused a great deal of water damage. At 2:40 pm heavy rain began and by 4:00 pm 1.40 inches of rain had fallen.  Two buildings under construction…with a projected cost of 100 thousand dollars…were badly damaged. The stone foundation and some of the brick walls were carried away by the storm waters.  Many basements were flooded…which damaged goods stored there.  Rainfall totaled 1.71 inches.

In 1964…lightning struck a building in Boulder…starting a fire and burning two workmen.

In 1968…a severe thunderstorm flooded streets…and hail- damaged trees and gardens…including flowers at a large commercial nursery in Boulder.

In 1969…severe hail damaged property…trees…and gardens… And heavy rain flooded streets and underpasses throughout metro Denver.  The heaviest amounts of rain fell in south Denver and Englewood where unofficial totals of 5 to 6 inches were reported.  Hail accumulated to 3 or 4 inches on the level and 2 to 3 feet deep in drifts.  Mud…debris…and hail carried by the heavy runoff clogged drains and increased the amount of flooding.  About 40 cars and a large truck were inundated at an underpass on an interstate highway…and several more were inundated or buried in mud in other areas.  A large number of basements were flooded. Streets and highways were heavily damaged in some areas. Rainfall totaled 1.66 inches at Stapleton International Airport.

In 1974…a late spring storm dumped 1.79 inches of rain over metro Denver…causing local flooding.  Strong gusty winds accompanied the storm…downing some power and telephone lines.  Northwest winds gusted to 56 mph at Stapleton International Airport where a trace of snow fell. Measurable snowfall occurred at mid-day over Aurora and suburban areas to the south of Denver.  A number of people were temporarily stranded in the mountains west of Denver where heavy snow fell.  Low temperature of 37 degrees equaled the record minimum for the date.  High temperature of 50 degrees was a record low maximum for the date.

In 1986…strong thunderstorm winds blew down a garage wall in Littleton and caused minor roof damage to several homes. Boats were overturned and damaged at a sporting goods store nearby.  As the storm moved northeast it produced a small tornado…which touched down in extreme southeast Denver and moved northeast into Aurora.  The twister did most of its estimated one million dollars damage shortly after touching down in an apartment complex and a shopping center.  Two apartments were completely unroofed; wooden chimney facings were demolished and metal pipes were twisted.  Many trees up to 25 feet high in the complex were uprooted. Doors were ripped off their hinges…and several parked cars were damaged.  In the shopping center…a wall of a building was stripped of its brick facing…and many windows were broken.  The twister picked up an aluminum rowboat…carried it 250 feet over some apartments…and deposited it in a vacant storefront.  Around 200 cars were damaged in the shopping center.  Benches bolted to the pavement were knocked over.  Six people suffered minor injuries caused by flying debris.  After hitting the shopping center and apartment complex…the tornado moved northeast into a residential area where it toppled some trees and damaged several fences.  The same storm later produced 3 separate small tornadoes 5 miles north of Watkins.

In 1987…torrential rain produced extensive flooding across metro Denver.  I-25 was closed for a time through central Denver…and a trailer park in Lakewood was partially evacuated due to high water.  Several streets in Boulder were closed due to flooding.  There was extensive basement flooding and water damage in Lakewood and southeast Denver. Lightning hit a power plant in Denver that supplied electricity to storm drain pumps which exacerbated street flooding in some areas.  Rainfall from the thunderstorms totaled 1 1/2 to 2 inches at many locations in Lakewood central and northeast Denver.  The heaviest amount of reported rain was in Lakewood where 2 1/4 inches fell in just 2 hours.  At Stapleton International Airport…1.62 inches of rain fell in an hour.  Rainfall totaled 1.76 inches for the day.

In 1988…a tornado touched down 15 miles northwest of Bennett and stayed on the ground for 15 minutes.  The twister was observed by national weather service personnel at Stapleton International Airport.   No damage was reported.

In 1989…a small tornado hit a neighborhood in southeast Aurora.  The twister hit a dozen homes…blowing out windows…knocking down fences…and partially unroofing one house.  About a half dozen trees were felled.  A basketball pole was severely bent.  The tornado was on the ground for about 2 minutes.  Total damage was estimated at 50 thousand dollars.  Lightning also struck a home in Parker…causing 25 hundred dollars damage.

In 1992…very heavy thunderstorm rains drenched southwestern Weld and eastern Boulder counties.  Measured rainfalls of over 2 inches an hour caused St. Vrain Creek to rise 2 feet out of its banks.  Boulder creek was also out of its banks along U.S. Highway 287.  I-25 flooded with 3 to 5 feet of water along a 9-mile stretch from the Erie exit to the Frederick exit.  The highway was closed for over 6 hours while snowplow drivers and farmers with tractors rescued stranded motorists.  Water rose into homes along south Boulder road in Lafayette.  Several small County roads were washed out along the Boulder County/Weld County line. An off-duty national weather service employee measured 3/4 inch hail in Thornton.  Several locations north of Denver had small hail up to 6 inches deep.  A funnel cloud was spotted 18 miles northeast of Stapleton International Airport.

In 1998…severe thunderstorms dropped large hail across metro Denver.  Hail as large as 1 3/4 inches in diameter fell near columbine in Jefferson County.  One inch diameter hail fell in Aurora and Littleton with 7/8 inch hail in Arvada and 3/4 inch hail at centennial airport… Near Greenwood Village…and in Parker.

In 2004…heavy rain and large hail caused flooding and flash flooding across northeast Jefferson County.  In Golden… Heavy rains triggered a small mudslide on U.S. Highway 6 near the intersection of Colorado highway 119.  Automated rain gages in the area registered 2 to 3 inches of rainfall in one hour.  Near the Colorado mills mall…numerous streets were inundated with 1 to 3 feet of water and hail…which stranded several vehicles…including a fire engine.  About 30 basements were flooded in Golden and Lakewood.  Many windows in both homes and cars were shattered by the large hail.  Hail as large as 1.5 inches in diameter was measured in and near Golden with hail to nearly an inch in diameter a few miles north of Evergreen.

In 2007…the low temperature in Denver bottomed out at 31 degrees…which established a new record minimum for the date.  It also became the latest date of the last freeze in Denver.

In 2014…in Aurora… A tornado touched down near the Blackstone Country Club…it lifted some golf carts and flipped an empty construction trailer. One of the carts was thrown on top of a caddy walking nearby; he was taken to a hospital with minor injuries. It was assigned an ef-1 rating. In Englewood…lightning struck a tree which damaged two nearby homes and a truck. Large hail…from quarter to half dollar size…was reported near Buckley Air Force Base and near Castle Rock. Other short lived tornadoes touched down near Byers and Roggen.

In 2019…severe thunderstorms erupted around metro Denver late in the afternoon and spread eastward onto the plains. The largest hail fell around Castle Rock…where hail up to 2 1/2 inches was reported. Elsewhere…the hail ranged from 1 to 1 1/2 inches.

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In 1900…an apparent cold front produced north winds to 42 mph with gusts to 47 mph.

In 1923…heavy rainfall totaled 2.18 inches in downtown Denver…where northwest winds were sustained to 27 mph. Heavy rain also fell in Boulder…causing flooding on Boulder and south Boulder creeks.

In 1939…post-frontal sustained northwest winds to 35 mph produced some blowing dust…which reduced the visibility to one mile at times during the afternoon.  Dusty conditions prevailed into the early evening.  The airport station reported a maximum wind of 56 mph.  A few minor injuries and some damage resulted.  A few trees were uprooted…some fruit was blown from trees…and a section of power lines was blown down.

In 1959…dry thunderstorm winds…estimated to near 70 mph… Toppled a 40-foot-high poplar tree…which was 4 to 5 inches in diameter…near Cherry Creek dam.  The Colorado State Patrol reported a possible tornado 1 mile south of the dam.

In 1960…strong gusty winds tore the roofs from 2 patios in Aurora.  One of the roofs was blown over a house and landed on a car damaging its top.  A house trailer was also overturned.  Other minor damage was reported to roofs… Windows…and trees in Aurora.  A thunderstorm wind gust to 43 mph was recorded at Stapleton Airport.

In 1963…golf ball size hail fell at Cheery Creek Reservoir.

In 1967…a small tornado damaged trees and a dwelling in south Denver.  The storm touched down at the intersection of 1st avenue and Harrison Street and moved northeast to the intersection of 3rd avenue and Albion Street. Damage included 3 small roofs removed…15-20 large trees uprooted…one car overturned and thrown against a house… Plus other minor damage.  A funnel cloud reported at the same time 10 miles north of Denver possibly touched ground. Later…funnel clouds were reported 12 miles south-southeast of Stapleton International Airport…10 miles southwest…and 5 miles north.  A tornado was sighted 3 1/2 miles east of Stapleton International Airport by weather bureau personnel for a duration of 5 minutes.  Heavy rain and some hail fell over much of the area.

In 1974…the start of the shortest seasonal snow free period on record…94 days…occurred with the last snow of the season…a trace…on the 8th.  The first snow of the next season occurred on September 11th when a trace of snow fell at Stapleton International Airport.  A funnel cloud was observed just east of Aurora and a small funnel was sighted just northeast of Stapleton International Airport.

In 1985…a thunderstorm wind gust to 62 mph was reported at Golden gate canyon in the foothills west of Denver.

In 1986…a thunderstorm…which dumped heavy rain and caused some street flooding across north metro Denver…produced a small tornado 5 miles east of Brighton.  No damage was reported.

In 1987…strong thunderstorm wind gusts in Conifer destroyed a porch on a house; the wind gust apparently picked up the porch and dropped it on a man…killing him.  The wind also damaged the roof of the house and a nearby barn.  The same thunderstorm spawned a tornado…which touched down briefly just south of Lakewood.  No damage was reported.  Up to 3 inches of rain fell in a short time 8 miles southwest of Littleton.  A few businesses in Englewood suffered minor water damage.  A tornado was sighted between Watkins and Bennett.  It was on the ground for 15 minutes.  A weak tornado also touched down 4 miles southwest of Castle Rock. The twister tossed an aluminum shed into the air and carried it about 100 feet.  A funnel cloud was sighted 15 miles east-northeast of Stapleton International Airport.

In 1988…golf ball size hail fell in Conifer along with 1.30 inches of rain.  Three miles north of Louisville…1.10 inches of rain fell in 20 minutes.  Ping pong ball size hail was measured in Arvada.

In 1990…3/4 inch hail fell in Castle Rock.

In 1991…hail two inches in diameter fell near Evergreen. Hail to 1 inch diameter fell in Lakewood where a funnel cloud was also sighted.  One inch diameter hail was also reported in Aurora.

In 2002…high temperatures…low relative humidities…and strong gusty winds allowed the Hayman Wildfire…located in the foothills to the southwest of Denver…to become the largest wildfire in the state’s history.  Although the fire was initially started by a U.S. Forest Service employee…the ongoing drought and dry conditions allowed the fire to spread rapidly out of control.  The wildfire consumed nearly 138 thousand acres of forest land and 133 homes before it could be contained and finally extinguished on June 30th.  About 1800 households had to be evacuated during the blaze.  Southwest winds aloft swept the smoke plume directly over metro Denver…creating poor air quality and blocking the sun.  Much of metro Denver choked on smoke with the southern suburbs receiving the most.  Smoke and ash restricted surface visibilities to a mile or less at times in the Denver and Castle Rock areas and to 2 miles at Denver International Airport.

In 2003…thunderstorm winds gusted to 51 mph at Denver International Airport.  The storm produced only a trace of rain.

In 2004…severe thunderstorms produced large hail across portions of metro Denver for the second day in a row. The most extensive damage occurred across southern sections of metro Denver in Aurora…Lakewood…Littleton…and south Denver.  The combined damage to homes and vehicles…not including commercial buildings…was estimated at 146.5 million dollars…making the event the 4th costliest insurance disaster in the state’s history.  Hail as large as 2 1/4 inches in diameter fell near southern Aurora with hail to 1 3/4 inches in the city of Denver and in Lakewood. Hail to 1 1/2 inches fell near Morrison with 1 inch hail measured in Thornton…near Buckley Air Force Base…and near Roggen.  Hail to 3/4 inch diameter fell in Littleton and near Conifer.  A small tornado touched down near Bennett…but did no damage.

9-10

In 1864…high water from melting snow combined with heavy rains over the upper reaches of the South Platte River forced the river over its banks and caused flooding of low lying areas along the river in the city.  The amount of rainfall in the mountains and in the city is unknown.

10

In 1943…a man was killed by lightning while using a surveying instrument at Buckley Field.

In 1969…hail stones 2 to 3 inches in diameter caused extensive damage to buildings and automobiles in an area from northeast of Boulder to Longmont.  Two funnel clouds were reported near Castle Rock.  A funnel cloud and 1 inch hail stones were reported 10 to 20 miles southeast of Stapleton International Airport.  Hail stones to 1 3/4 inches fell 3 miles west of Littleton.  Hail to 3/4 inch diameter fell over southeast Denver.

In 1988…thunderstorm winds clocked to 60 mph unroofed a porch and downed a fence at a home near Stapleton International Airport.  A small tornado touched down briefly in northeast Aurora.  Another small tornado touched down for 3 minutes in southeast Aurora.  No damage was reported from either twister.

In 1989…a national weather service observer saw lightning strike 2 storage tanks at 40th and Havana…3/8 mile northeast of Stapleton International Airport.  The strike temporarily knocked out some weather observing equipment at the national weather service.

In 1991…a tornado was sighted 2 miles south of Castle Rock. No damage was reported.  The funnel cloud associated with the tornado was sighted for 5 minutes by national weather service observers at Stapleton International Airport.

In 1994…lightning struck a home in Denver…which started a fire in the attic and caused minor damage.

In 1997…lightning struck a security guard at the castle pines golf course near Castle Rock.  He received only minor injuries.

In 1999…severe thunderstorms rolled off the foothills over metro Denver…producing large hail and damaging winds.  Hail to 1 inch diameter fell near Evergreen with 1 3/4 inch hail measured west of Golden.  Hail to 1 1/2 inches fell in Commerce City with one inch hail in Lakewood…Wheat Ridge… The city of Denver and at Denver International Airport where thunderstorm winds gusted to 58 mph.  As the storms moved east…3/4 inch hail was reported in Aurora…and damaging thunderstorm winds developed between Bennett and Strasburg.  Winds gusting as high as 69 mph blew half a metal roof from a shed in a Bennett lumberyard.  A small barn was also leveled between Bennett and Strasburg.  Winds also gusted to 58 mph near Manilla.

In 2000…a dry microburst produced a wind gust to 58 mph at Jefferson County airport.  Thunderstorm winds gusted to 55 mph at Denver International Airport.

In 2003…hail as large as 1 3/4 inches was measured at centennial airport and near Parker.

In 2005…hail to 7/8 inch in diameter was reported near Parker with 3/4 inch hail measured near Castle Rock.

In 2010…a complex of severe thunderstorms hammered portions of eastern Arapahoe…eastern Douglas and western Elbert counties. The hail ranged from 1 inch to 3 inches in diameter. The largest hail was observed near Elizabeth. Areas in and around Aurora…Byers… Parker and Thornton were also impacted by large hail. One weak tornado touched down near prospect valley but did no damage. At Denver International Airport…a peak wind gust to 35 mph was observed from the northwest.

10-11

In 1882…heavy thunderstorm rains on the morning of the 10th caused a rapid rise in dry creek…which enters the South Platte River at fairview in present day south Denver.  This…combined with additional heavy rainfall on the 11th caused the South Platte River to overflow. Five people drowned and several houses were destroyed. Total losses in the city and suburbs was estimated at 75 thousand dollars.  Total rainfall in central Denver was 2.21 inches over the 2 days.

In 2013…the high temperature of 99 degrees on the 10th broke the previous record maximum temperature of 97 for the date. Also…the minimum temperature of 68 and high temperature of 100 degrees on the 11th established a new record for highest minimum and maximum temperature for the date.

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In 1947…a trace of snow fell over downtown Denver.  Low temperature of 34 degrees was a record minimum for the date.

In 1962…hail caused extensive crop damage near Hudson northeast of Denver.

In 1970…stratiform rainfall totaled 3.16 inches at Stapleton International Airport.  This was the greatest amount of precipitation ever recorded on a calendar day in June. In addition…it was the greatest amount of precipitation ever measured during any 24-hour period in June.  The high temperature climbed to only 51 degrees…which was a record low maximum for the date.

In 1973…large hail from 3/4 to 1 1/2 inches in diameter fell west of Boulder.

In 1977…golf ball size hail was reported just south of Arapahoe County airport…now centennial airport.  Lightning struck a home in Lakewood.

In 1988…a 30-year-old man was seriously injured by lightning while mowing his lawn in Denver.

In 1992…lightning started two house fires in the southern Denver suburbs where 3/4 inch hail fell and a funnel cloud was sighted.

In 1999…severe thunderstorms formed over the palmer divide and moved across Douglas…Elbert…and Adams counties. Hail as large as 1 inch in diameter was reported in and near Castle Rock…Sedalia…Franktown…and Aurora.  Hail as large as golfballs accumulated several inches deep and caused a large section of a corrugated metal roof of a greenhouse complex to collapse near Franktown.  About a third of the roof covering the 30 thousand square foot building collapsed.  Thirty-five workers were trapped in the debris…but only 3 were treated for minor injuries. Hail 1 to 2 feet deep blocked the roadways and slowed the arrival of emergency vehicles.  Damage to the building was estimated to be around 3 million dollars.

In 2006…a man was struck and killed by lightning as he was returning to his car after leaving the mile high flea market near Henderson.  Two others were knocked down…but not injured by the lightning strike.  Severe thunderstorms produced large hail across the northern portion of metro Denver.  Hail to 1 1/4 inches in diameter was measured in Arvada…with 1 inch diameter hail reported near Fort Lupton.  Hail to 7/8 inch in diameter was recorded near Brighton…and hail…3/4 inch in diameter…fell near Keenesburg.

In 2010…severe thunderstorms producing very large hail pummeled portions of Front Range foothills and urban corridor. The large hail ranged in size from 1 to 2 1/2 inches…caused extensive damage to home and vehicles. The hardest hit areas included: Brighton… Castle Rock…Greenland…Idledale… Mountain View and Thornton. The combination of heavy rain and hail destroyed 50 thousand acres of cropland in southeast Weld County. Flash flooding forced the closure of State Highway 52…east of Prospect Valley. Several county roads were either flooded or completely washed out. At Denver International Airport…0.69 inches of rainfall was observed.

In 2015…thunderstorms produced flash flooding in Denver and parts of the metropolitan area. In downtown Denver… parked cars had standing water rising midway up the wheels. Denver fire crews had to rescue motorists from flooded intersections and roads. In Glendale…two lanes of northbound Colorado Blvd. at Exposition Ave. were closed due to flooding. In Aurora…water was reportedly flowing over the roads at East 6th Ave. and South Pacadilly Road. Additional flooding was reported on South Gun Club Road… between East Alameda Ave. and East Exposition Avenue… forcing the closure of the road. Flooding occurred along Plum Creek and its tributaries. Four trails in Castle Rock were closed due to flooding. Plum Creek remained above flood stage for approximately 2 1/2 hours…with moderate flooding along and east of the creek. Near Cherry Creek Dam…2.02 inches of rain fell. At Denver International Airport 0.56 inches of rainfall was recorded. A peak wind gust to 34 mph was also observed from the north.

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In 1999…damage from several hailstorms in and near metro Denver totaled 35 million dollars.  About 17.5 million dollars was from automobile claims with another 17.5 million in homeowner claims.  The areas hardest hit by the storms included Castle Rock…Commerce City…Evergreen… And Golden.

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In 1901…south winds were sustained to 45 mph with an extreme velocity to 47 mph.

In 1917…northwest winds were sustained to 40 mph with gusts to 45 mph.

In 1927…flooding on little dry creek in Englewood resulted in two deaths.

In 1947…a trace of snow fell over downtown Denver during the early morning.  This was the latest last snow of the season (trace or more).  This also marked the end of the longest snow season…264 days…from the first snow…a trace…on September 22…1946.  High temperature of 43 degrees was a record low maximum for the date.  Minimum temperature of 33 degrees was a record low for the date.

In 1971…a funnel cloud sighted over Arvada possibly touched down at the base of the foothills.  The public reported 3/4 inch to 1 inch diameter hail over the city of Denver.

In 1974…strong thunderstorm winds caused damage to power lines in metro Denver.  Northwest winds gusted to 45 mph at Stapleton International Airport.

In 1975…a thunderstorm wind gust to 56 mph was recorded at Stapleton International Airport.

In 1982…three small tornadoes were sighted near Bennett. One of the twisters caused minor crop and road damage along its path.  A brief tornado was sighted by national weather service observers at Stapleton International Airport.

In 1983…3/4 inch hail fell in Boulder.  Golf ball to 3/4 inch size hail fell in Arvada…denting cars and house roofs. Over a thousand hail damage insurance claims were filed from the area.  Golf ball size hail also fell in Northglenn and Bennett…1 to 2 inch hail in Thornton…2 1/2 inch hail in northeast of Denver.  A tornado was sighted 10 miles northeast of Stapleton International Airport; it was only on the ground for 1 to 2 minutes.

In 1984…large hail pelted many parts of southern metro Denver.  Fifteen aircraft were damaged by golf ball size hail at centennial airport.  Golf ball size hail was reported in south Denver…and 3/4 inch hail was measured in southeast Aurora.

In 1987…a small weak tornado touched down for about 3 minutes near the intersection of I-70 and Colorado blvd. In northeast Denver.  No damage was recorded.  A microburst wind gust to 53 mph was recorded at Stapleton International Airport.

In 1991…in the city of Denver…lightning struck a tree under which seven people were picnicking.  One person was critically injured.  The others received only minor injuries.

In 1992…golf ball size hail fell in Evergreen.

In 1994…microburst winds gusting to 53 mph kicked up some blowing dust at Stapleton International Airport.

In 1996…lightning struck a house in Parker…which sparked a fire.  The bolt was strong enough to blow nails out of the drywall in one room.  About 85 percent of the house was damaged.  No dollar estimate of the damage was available. Lightning also struck a power line in Boulder…which left 250 customers without electricity for a short time.

In 1997…a tornado touched down near Parker…damaging some construction equipment.  Hail to 2 inches in diameter was measured in Henderson.  One inch diameter hail fell in the city of Denver with 3/4 inch hail measured in Lakewood.

In 1999…hail as large as 1 1/2 inches in diameter struck Hudson.  A funnel cloud was sighted by ramp personnel to the east of Denver International Airport.

In 2003…lightning blew a hole in the roof of a house in Highlands Ranch.  The bolt knocked several holes in the bedroom ceiling and damaged the home’s electrical system.

In 2004…lightning struck a home in Louisville…but caused only minor damage.

In 2006…a strong microburst wind gust…estimated at 69 mph… Ripped the roof off a horse barn near the intersection of Havana Street and Smith Road in Denver.  A 13 year old girl was injured…when she was thrown from a horse inside the barn at the time the roof was being torn off.  A thunderstorm produced a microburst wind gust to 54 mph and a trace of rainfall at Denver International Airport. A severe thunderstorm produced hail to 0.75 inch near Watkins.

In 2022…a short-lived landspout was observed north of Denver International Airport. No damage was observed.

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In 2000…two large wildfires developed in the Front Range foothills as careless campers and very dry conditions proved to be a dangerous combination.  Strong winds gusting in excess of 60 mph on the 13th fanned the flames… Spreading both wildfires out of control.  Winds gusted to 78 mph atop Niwot Ridge near the continental divide west of Boulder.  The hi meadows wildfire…about 35 miles southwest of Denver…consumed nearly 11 thousand acres and 80 structures…mostly high priced homes.  The bobcat wildfire…located about 12 miles southwest of Fort Collins… Consumed nearly 11 thousand acres and 22 structures.  Late on the 16th…a strong cold front moved south over the great plains into northeastern Colorado.  Low level upslope conditions developed in the wake of the front…producing 2 to 4 inches of snowfall overnight at elevations above 8 thousand feet.  Firefighters were able to contain both fires shortly thereafter.

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In 1956…a microburst caused a brief wind gust to 59 mph at Stapleton Airport.

In 1957…an unconfirmed tornado appeared to touch the ground in the vicinity of Franktown.  No damage was reported from the twister.

In 1968…a violent gust of wind…possibly associated with a thunderstorm…caused 75 hundred dollars damage in Boulder.

In 1973…hail…1/2 to 3/4 inch in diameter…fell over Lakewood.  Flash flooding occurred in west Denver from the same storm.

In 1974…a thunderstorm wind gust to 64 mph was recorded at Stapleton International Airport.

In 1977…hail the size of table tennis balls…1 1/2 inches in diameter…was reported in Boulder.

In 1981…large hail to golf ball size fell in Denver… Northglenn…and Brighton.  Hail as large as baseballs was reported in federal heights.

In 1984…one of the worst hailstorms ever experienced in metro Denver struck the northwestern suburbs of Arvada…Wheat Ridge…and Lakewood…but large hail also fell in Golden… Southeast Denver…and Aurora.  Homes and other buildings sustained around 200 million dollars in damage.  Thousands of cars were battered by giant hailstones…and total damage to vehicles was estimated at 150 million dollars.  In some areas…golf ball size hail fell continuously for 30 to 40 minutes.  Some places were pelted with a few stones as large as grapefruits!  Roofs on thousands of structures were severely damaged.  Uncounted car windshields were broken; two-thirds of Arvada’s police cars were rendered inoperable.  Torrential rains…with as much as 4.75 inches in Lakewood clogged drains and caused widespread damage from flooding.  In some places hail was washed into drifts several feet deep.  About 20 people were injured by the giant hailstones.  One couple was hospitalized.  A woman drowned when she was trapped under a trailer by high water. Only pea size hail fell at Stapleton International Airport.

In 1988…2 inch hail fell in Parker.  Soft hail 1 inch in diameter fell at the mouth of turkey creek canyon 5 miles southeast of Morrison.  Hail between 1 inch and 1 3/4 inches fell at both Bennett and Strasburg.  A tornado touched down briefly at Strasburg.  A brief funnel cloud was sighted by national weather service observers 15 miles southwest of Stapleton International Airport.

In 1991…a Boulder man was injured when struck by lightning while in a tent.  He received only minor burns.

In 1997…lightning struck a home in Denver.  The extent of the damage was unknown.  A home in Littleton was also struck.  The house caught fire…but the extent of the damage was not known.

In 1998…a strong mountain wave produced a brief period of high winds along the Front Range.  A small building atop squaw pass west of Denver was blown down.  Tree limbs were downed across metro Denver.  Peak wind gusts included:  80 mph on squaw pass…69 mph at Jefferson County Airport near Broomfield…and 60 mph in Westminster and at the National Center for Atmospheric Research in Boulder.  West-northwest winds gusted to 51 mph at Denver International Airport.

In 2001…high winds developed briefly in Boulder County. A peak wind gust to 76 mph was recorded at the National Center for Atmospheric Research atop the mesa in Boulder. A wind gust to 72 mph was recorded at southern hills middle school in Boulder.  Lightning started a small fire…which damaged the roof of a house in greenwood village.

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In 2006…the high temperature of 99 degrees on the 13th equaled the record maximum temperature for the date first set in 1994.  The high temperature of 102 degrees on the 14th was a new record maximum temperature for the date.

The City of Thornton has announced that it has replaced the old CodeRed emergency alert system with a new one called “ThorntonReady Emergency Alerts.”  We highly recommend all residents sign up for the new system immediately.

With the system you can choose exactly which types of events you want to be notified about – civic alerts, weather advisories, weather warnings, etc. Additionally, you control how you want to be notified whether by phone call, text, email or all of them.

We found that they wanted to alert users with an entire gamut of alerts, many which don’t really warrant a middle-of-the-night phone call. However, the ability to be notified about the more common advisories is a nice touch and helps to keep you informed.

• In the news: Colorado city’s new opt-in emergency alert service warns residents about disaster events (CBS 4)

For us, we opted out of calls for advisories although being geeks we don’t mind the texts or emails. For calls, we chose only tornado warnings. If you are in an area where appropriate, we would suggest also opting in for calls for flash flood warnings. See attached screenshot of our choices.

Should you desire, you can also add information about your household that could be seen my emergency responders should an emergency arise. These include other members of the household, special health requirements, pets and more.

We chose not to add the personal information at this time as we are somewhat suspicious of what that information could be used for and who it may be shared with beyond first responders.

This service is crucial to ensuing you are notified about dangerous conditions at your home. Please do sign up.

Click here to learn more and sign up for ThorntonReady Emergency Alerts.

Extreme weather can occur during in month in Colorado we well know.  June however is when traditional spring severe weather arrives in the state oftentimes with hail, damaging wind and tornadoes.

Over 40 percent of the tornadoes that occur in Colorado happen during the month of June.  Far more common are thunderstorms with hail and wind, each responsible for extensive damage each year.

While severe weather is common, so too are brilliantly sunny and mild days as we close out spring and enter summer.  If you are looking for cold, it isn’t likely but it is possible as the Denver area has seen freezing temperatures and yes, even snow, during the month.

Read more about Thornton and Denver’s June weather and a look ahead at this year.

An extremely eventful week in Denver weather history.  Most notably for longtime Thornton and Northglenn residents is the 28 year anniversary of the infamous Thornton Tornado which struck on June 3, 1981.

From the National Weather Service:

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In 1995…a cool period with light morning showers and moderate to heavy afternoon showers and thunderstorms pushed rivers already swollen from mountain snow melt over their banks causing minor flooding.  Streams and rivers such as the South Platte and Boulder Creek flooded meadowlands…bike paths…roads near streams…and other low lying areas.  No significant property damage was reported and crop damage was unknown.  Rainfall totaled 1.79 inches at the site of the former Stapleton International Airport and only 1.51 inches at Denver International Airport.

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In 1894…heavy rain combined with snowmelt runoff caused widespread flooding over the South Platte River basin. Rainfall was heaviest in the foothills where 5 to 8 inches were measured over the 4 days.  Heavy rainfall west of Boulder flooded mining towns and damaged mining properties.  In the canyons above Boulder…railroads and roads were washed out along with many bridges.  The floodwaters spread into central Boulder and covered a wide area from University Hill north to near Mapleton Hill to a maximum depth of 8 feet.  Many houses were swept away…and every bridge in Boulder was destroyed. A few people…trapped in their homes by the floodwaters… Had to be rescued.  However…the gradual rise of the flood waters resulted in only one death.  Boulder Creek spread to a width of nearly one mile in the pasture land to the east of Boulder.  Extensive flooding on Left Hand Creek north of Boulder washed away railroad and wagon bridges.  The heavy cloudbursts caused flooding on Bear Creek…which washed away bridges…railroad tracks…and structures and destroyed the canyon roadway.  Morrison sustained the heaviest flood damage on bear creek.  In Denver…rainfall totaled only 1.50 inches on the 30th and 31st…but the heavy rainfall on upstream tributaries of the South Platte River caused the river to rise as much as 10 feet above the low water mark in the city…which caused some flooding of pasture land downstream to a depth of 6 feet near Brighton.

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In 1935…heavy thunderstorm rains overnight caused flash flooding east of the city on both Kiowa and Bijou Creeks… Resulting in a total of 9 deaths.  Most of the damage was on Kiowa Creek where there were more structures.  The water rose rapidly during the storm…ripping houses and stores from their foundations and sweeping them downstream. Precipitation in Denver totaled only 0.01 inch.  Hail fell in the city for a short time.  The hail was very small and caused no damage.

In 1983…a late storm of rain and snow hit the Front Range. Over an inch of rain fell at some spots…and above 7 thousand feet…1 to 5 inches of snow whitened the ground. Some snow flakes even fell in the western suburbs of metro Denver on the night of the 30th.

In 2002…unseasonably warm weather at the end of the month resulted in 3 temperature records.  High temperature of 91 degrees on the 30th equaled the record maximum for the date.  Low temperature of 61 degrees on the 31st was a record high minimum for the date.  High temperature of 93 degrees on the 31st was a record maximum for the date.

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In 1917…rainfall totaled 0.55 inch and was mixed briefly with snow around midday.  Only a trace of snow fell. Cold temperatures during the day resulted in a high of 44 degrees and a low of 35 degrees.  The month closed as the coldest May on record with a mean temperature of only 48.7 degrees…about 8 degrees below normal.  The cold temperatures during the month had a marked effect on shade trees and shrubs in the city.  Elms were just starting to leaf.  Leaves on cottonwoods and maples were only half formed.  Lilacs were just blooming…and snowball clusters would not bloom for days.

In 1959…the public reported a tornado briefly touching the ground 10 miles south of Stapleton Airport.  No damage was reported.

In 1984…a thunderstorm microburst produced a wind gust to 67 mph…7 miles east of Boulder.

In 1991…hail to golf ball size pummeled southern and southeastern sections of metro Denver and continued on east to Watkins.  Several houses and cars were damaged.  Later… Thunderstorms dumped heavy rain across the city of Denver… Causing street flooding in an area just south of downtown and just northwest of downtown.  Water was up to 10 inches deep over northwest Denver.  A brief tornado touched down in Castle Rock where 3/4 inch diameter hail also fell.

In 1993…thunderstorms dropped dime size hail in Commerce City.

In 1994…lightning struck an apartment in Louisville and damaged electronic equipment…including a computer.

In 2006…a severe thunderstorm produced 1 inch diameter hail near Boulder.

In 2022…moderate to heavy snowfall impacted the Front Range mountains and foothills. Above 8 thousand feet…storm totals generally ranged from 4 to 9 inches…with locally higher amounts. The big winner in the event was near Blue Valley south of Idaho Springs…which picked up 16 inches of snow. Several brief road closures occurred along Westbound I-70…from Floyd Hill to Silverthorne. Along the urban corridor and in the foothills below 8 thousand feet…much needed rainfall up to 1.5 inches was observed. The official rainfall measurement at Denver International Airport was 0.71 inch.

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In 1875…a windstorm during the late afternoon and early evening produced sustained winds to 50 mph.

In 1898…south winds were sustained to 41 mph with gusts to 46 mph.

In 1917…a trace of unmelted snow fell in downtown Denver. Precipitation for the day totaled 0.08 inch…half of which was estimated to be from melted snow.

In 1919…snowfall of 0.4 inch was measured in downtown Denver.  This was the greatest calendar day and 24-hour snowfall ever recorded during the month of June. Precipitation (rain and melted snow) totaled 0.15 inch. Two temperature records were set.  The low temperature of 32 degrees was a record minimum for the date.  The high temperature of only 40 degrees was a record low maximum for the date and the month.  North winds were sustained to 36 mph with gusts to 40 mph.

In 1951…a trace of snow fell at Stapleton Airport.

In 1961…hail as large as 1 1/2 inches in diameter fell in west Denver with hail to 1 1/4 inches reported in derby.

In 1965…a man struck by lightning in southeast Denver died shortly after being admitted to a hospital.  Lightning damaged power lines in east and southeast Denver.

In 1980…strong thunderstorm winds blew in the windows of a mobile home in Northglenn.

In 1990…a thunderstorm produced wind gusts to 63 mph in Boulder.  A small tornado touched down in a farmer’s field between the towns of Louisville and Lafayette.  Another tornado was spotted in an open field 3 miles west of Brighton.  A funnel cloud was sighted near Hudson. A microburst wind gust to 55 mph was recorded at Stapleton International Airport.  No damage was reported from any of these events.

In 1991…severe thunderstorms producing large hail…damaging winds…funnel clouds…and heavy rain were widespread across metro Denver.  Funnel clouds were reported in Lakewood… Boulder…Arvada…and just east of the rocky mountain arsenal.  Hail up to golf ball size fell in Lakewood…just west of Sedalia…in Littleton…Arvada…Englewood…and the city of Denver.  A mobile home park in Jefferson County reported hail to 3 feet deep.  Up to 1.00 inch of rain fell in 45 minutes near Boulder…causing Boulder Creek to flow out of its banks.  Rock and mud slides forced the closure of many roads in Boulder County.  Later in the afternoon thunderstorms produced rainfall amounts of 2 to 3 inches over a couple of hours.  Clear Creek in Golden spilled over onto U.S. Highway 6.  Heavy rains washed away part of a bridge near Erie.  Water was up to 18 inches deep in Westminster.  Wind gusts to 58 mph were reported at Stapleton International Airport where 1/4 inch hail fell… And heavy thunderstorm rainfall totaled 0.82 inches…briefly reducing the visibility to 1 1/4 miles.  Estimates of total damage from these storms would exceed 7 million dollars.

In 1994…hail up to 1 inch in diameter fell over south Denver and Littleton.

In 1997…two short lived-tornadoes formed near Bennett…but did no reported damage.

In 2002…strong winds from the outflow of dissipating showers developed to the east of Denver.  Near Strasburg…a spotter recorded a wind gust to 58 mph.

In 2019…severe thunderstorms produced large hail from 1 to 1 3/4 inch hail east of Centennial and over southeast Aurora.

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In 2002…unusually very warm weather for so early in June resulted in two temperature records.  Maximum temperatures of 96 degrees on the 1st and 93 degrees on the 2nd were record highs for each date…respectively.

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In 1977…unusually warm weather for this early in June resulted in 3 maximum temperature records being equaled at the time:  88 degrees on the 1st…90 degrees on the 2nd… And 93 degrees on the 4th.  Maximum of 91 degrees on the 3rd was not a record.

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In 2012…it was the hottest June in Denver since weather records began back in 1872. The average temperature for the month was 75.0 degrees which was 7.6 degrees above normal. There were a total of seventeen 90 degree days in the month of June. The highlight of record setting month was a stretch of five consecutive 100 degree days from the 22nd to the 26th. This was only the third time in Denver weather history in which this happened. Two of the high temperatures during the stretch peaked at 105 degrees… Which set the all-time record for the month of June and tied the all-time maximum temperature for Denver.

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In 1914…flooding occurred on Boulder creek when heavy rains added to heavy snowmelt runoff.  Flooding damaged the water supply system from the mountains into Boulder and destroyed roads and bridges in the canyons above Boulder.  The flooding in central Boulder was described as the worst since the tragic flood of May 29th through June 3rd in 1894.  However…there was no reported loss of life.  The flood waters also inundated pasture land to the east of the town.

In 1951…the lowest recorded temperature in June…30 degrees… Occurred. The unusually cold weather was accompanied by 0.3 inch of snowfall.  Precipitation…both rain and melted snow…totaled 0.30 inch.

In 1966…microburst winds gusted to 51 mph at Stapleton International Airport.

In 1981…a severe thunderstorm roared through metro Denver… Dumping 2.00 inches of rain in as little as 20 minutes and bombing many areas with hail to 1 3/4 inches in diameter. The heavy rain caused local flooding with up to 3 feet of water in some streets in northwest metro Denver.  Part of a street was washed out in Thornton.  Lightning strikes started a fire and caused a power outage just north of Denver.  Lightning also struck a barn which burned to the ground in Brighton.  Numerous cars sustained minor hail damage.  A tornado was spotted 4 miles northeast of the rocky mountain arsenal…but caused no damage.

In 1982…severe thunderstorms produced large hail across metro Denver.  Hail to 3/4 inch in diameter was reported in Louisville and northeast Denver.  Golf ball size hail fell near Strasburg where two tornadoes were also sighted.

In 1983…a tornado touched down 5 miles south of Bennett.  It destroyed an outbuilding and did extensive damage to greyhound dog shelters.  Golf ball size hail fell near the tornado…destroying some hay.

In 1985…3/4 inch hail fell in southwest metro Denver.

In 1989…large hail fell over eastern and central Denver.  A few stones were as large as baseballs…and many ranged from 3/4 inch to golf ball size.  The hail piled up 2 to 4 inches deep in some areas.  Hail to 3/4 inch fell at Buckley Field in Aurora…and 7/8 inch hail fell just east of Aurora.  A home in Louisville was struck by lightning and was 30 percent destroyed by the ensuing fire.

In 1991…strong thunderstorm winds in Arapahoe County…14 miles southeast of Stapleton International Airport…damaged the roof of a home and a radio antenna.  A funnel cloud… 4 miles northeast of Stapleton International Airport…was sighted for 11 minutes by national weather service observers.

In 1993…a tornado touched down briefly in south Denver… Destroying the 4-inch thick concrete roof of a building and causing about 20 thousand dollars in damage.  The twister also picked up a trash dumpster and dropped it onto a car 30 feet away…causing an estimated 3 thousand dollars in damage.  Hail up to an inch in diameter fell in Aurora… Conifer…and Bennett.  Two funnel clouds were spotted near Deckers.  A funnel cloud was sighted for 19 minutes by national weather service observers to the southwest of Stapleton International Airport.

In 1994…lightning struck two homes in Denver…starting fires which caused considerable damage to both.  Hail to 3/4 inch in diameter fell in Golden.

In 1995…lightning struck a house in Nederland…causing a fire that was doused by subsequent rainfall.  A portion of the roof and wall was damaged.  The storm also left most of Nederland without power for two hours.  Lightning also struck a high chimney of an elementary school in west Denver.  The jolt sprayed bricks around the school yard and parking lot.  Twenty students and teachers were in the school building at the time…but all escaped without injury.  A funnel cloud was sighted over Fort Lupton…and 3/4 inch hail fell in Lafayette.

In 2003…severe thunderstorms produced strong winds and large hail.  Hail as large as 1 1/2 inches in diameter fell near Parker.  Estimated wind gusts to 70 mph occurred near Parker and near Denver International Airport where thunderstorm wind gusts to 52 mph were recorded.  Wind gusts to 60 mph were estimated near Bennett.

In 2005…a severe thunderstorm produced hail as large as 1 inch in diameter in the city of Denver.  A tornado was sighted near Bennett along with 3/4 inch hail.

In 2008…severe thunderstorms produced large hail over western Arapahoe…northern Denver and southern Weld counties.  Hail…2 inches in diameter…was observed near Brighton; with hail to 1 1/2 inches in diameter…5 miles east of prospect.  Hail to one inch in diameter was observed near Buckley Field…Frederick and Denver.

In 2012…severe thunderstorm produced damaging thunderstorm winds.  Peak wind gusts included:  82 mph near Strasburg… 61 mph at Buckley Field…60 mph near byers and southwest Denver…58 mph near Watkins and 52 mph at Denver International Airport.  The microburst winds caused extensive tree and roof damage.  In addition…hail up to 1 inch in diameter was reported 3 miles east-southeast of Parker.

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In 1989…heavy rain drenched metro Denver with the greatest amounts recorded on the 3rd.  Total rainfall ranged from 1 1/2 to 3 inches.  Roads were washed out in Boulder County… And flooded basements caused water damage to houses in the Gunbarrel section of Boulder.  In suburban Denver…heavy rain caused minor flooding along Lena Gulch in Jefferson County where two mobile home parks were evacuated. Rainfall totaled 1.66 inches at Stapleton International Airport.

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In 1921…heavy rainfall for nearly a week…on top of streams already swollen by mountain snowmelt…produced widespread flooding over the South Platte River basin…including the tributaries through the canyons to the west and southwest of Denver.  Heavy rainfall over the 6-day period totaled 3.36 inches in Boulder…4.98 inches in Morrison…4.27 inches in Castle Rock…and 2.94 inches in the city of Denver. Rainfall amounts in the foothills were estimated between 3 and 6 inches.  The narrow-gauge tracks of the Colorado and Southern railroad were destroyed in the Platte Canyon.  From the mouth of the canyon through the city to near Brighton… The river spread from 1/2 to nearly 1 1/2 miles wide… Flooding farm and pasture land and destroying or damaging many bridges.  In the city…many businesses along with as many as 500 homes were inundated…forcing their evacuation. Bridges were swept away.  The high waters flooded the rail yards and stock yards in lower downtown…closing three adjacent packing houses.  The heavy rains also caused flooding on Boulder creek in Boulder on the 6th.

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In 1951…a trace of snow fell at Stapleton Airport.

In 1961…torrential rains fell 10 to 30 miles north of Denver…causing flooding in the town of Frederick.  The rush of water broke through and over a retaining dike sending a 5-foot wall of water into the town…flooding homes and damaging sewer lines…roads…and streets. Golf ball size hail fell in derby…west Denver…and Lakewood…causing more than one million dollars in damage.

In 1981…severe thunderstorms produced tornadoes over metro Denver.  The first tornado touched down at the intersection of Alameda Ave. and Sheridan Blvd.  The twister moved north along Sheridan blvd….damaging businesses…apartment buildings…homes…and vehicles.  Over ten homes were unroofed.  The roof of one landed in the middle of a neighborhood park.  At least 10 mobile homes were wrecked. The tornado curved to the northeast into northwest Denver… Hopping up and down in several places.  Very strong winds outside the actual funnel caused 20 to 30 thousand dollars in damage in downtown Denver.  The third floor of one old building was demolished.  No major injuries were reported from the tornado…although several people were hurt slightly in traffic accidents on Sheridan blvd. In the confusion caused by the storm.  Damage in Lakewood alone was estimated at 200 thousand dollars.  At the same time… The worst tornado to ever hit metro Denver struck Thornton. Coming from the same thunderstorm that spawned the Denver twister…the Thornton tornado tore a swath through the heart of the city.  87 homes were destroyed…110 others damaged at least moderately.  In all…600 homes in a 100 block area sustained some damage.  The twister also hit shopping centers…several restaurants…and other buildings. Seven of the 42 injured were considered serious.  The storm was strong enough to snap lamp posts in half and drive a 6- inch slab of wood 2 feet into the ground.  Damage was estimated at up to 50 million dollars.  The same storm that struck Thornton produced another damaging tornado that touched down in the northwest section of Fort Lupton.  This twister damaged 16 homes and numerous cars and campers. Two children were slightly injured when the car they were in was knocked about and its windows shattered by the storm.  The twister also damaged two commercial buildings.  Damage was very spotty…and observers said the storm hopped up and down at least 3 times.  Dollar damage was estimated at 500 thousand dollars.  The thunderstorm complex that produced 3 damaging tornadoes also dropped large hail which damaged many cars over northwest Denver.  One to 2 inches of rain fell in less than an hour…flooding a mobile home park with 3 to 4 feet of water on the northwest edge of Denver.  The high water damaged about half of the 392 homes in the park.  Local flooding was also reported in other areas across metro Denver.  A tornado was also sighted near Franktown…but caused no damage.  A thunderstorm wind gust to 52 mph was recorded at Stapleton International Airport.

In 1982…a cold air funnel cloud touched down briefly in southwest Denver.  Two tornadoes were briefly spotted near Watkins.  No damage was reported from these storms.  A brief funnel cloud was sighted by national weather service observers at Stapleton International Airport where 1/4 inch hail fell.

In 1984…there were several sightings of tornadoes around Parker.  No damage was reported.

In 1985…a tornado just southeast of Aurora was spotted by a national weather service employee.  No damage was reported. Severe thunderstorms pummeled the metro area with hail. One inch to baseball size hail was reported in south Lakewood…one inch hail in Littleton…3/4 inch to 1 inch hail in Aurora…and golf ball size hail in south Denver.

In 1989…hail up to golf ball size fell over Arvada.  A golf course had to be evacuated as the hail accumulated up to 3 inches deep in some places.  One inch diameter hail fell in west Denver and Westminster.

In 1993…an early morning thunderstorm produced lightning… Which caused an attic fire at a residence in Niwot northeast of Boulder.  Damage was estimated at 40 thousand dollars.  No one was injured.

In 1994…hail to 1 1/2 inch diameter fell just northeast of Boulder.  One inch diameter hail fell in Golden. Thunderstorm wind gusts to 70 mph were recorded in Erie.

In 1995…a tornado was sighted over open country near Strasburg.  No damage was reported.  A funnel cloud was sighted 11 miles east of Aurora where 3/4 inch hail fell.

In 2001…severe thunderstorms produced large hail over east and southeast metro Denver.  Hail as large as 1 3/4 inches in diameter fell at centennial airport with 1 1/2 inch hail near Buckley Field…1 1/4 inch hail in Parker…1 inch hail near Elizabeth…7/8 inch hail at Cheery Creek Reservoir…and 3/4 inch hail 20 miles north of Kiowa in Elbert County.

In 2002…severe thunderstorms dumped large hail across metro Denver.  Hail to 1 3/4 inches in diameter fell over southeast Denver and 4 miles north of Aurora.  Hail to 1 1/4 inches pelted Parker.  One inch hail was measured near Ft. Lupton…and 3/4 inch hail fell 9 miles southeast of Buckley Field…near Strasburg…and at the site of the former Stapleton International Airport.

In 2005…thunderstorms producing heavy rain and hail caused flash flooding over parts of southeast metro Denver. People became trapped in their vehicles by the high water… And numerous water rescues were required.  The hardest hit areas included the vicinity of I-25 and Alameda Avenue…as well as the intersection of Yale Avenue and Quebec Street. Several basements were flooded along Eastman Place. Severe thunderstorms brought heavy rain and hail to eastern Centennial and southeastern Aurora.  Up to 3 feet of standing water was reported on east orchard road where several motorists were stranded in their vehicles and needed to be rescued.  Hail to 3/4 inch in diameter fell in the area.  Ten vehicles were stranded on Grand Avenue…and most had to be towed once the floodwaters receded.  Water was reportedly chest deep at one location on Girard Avenue. Hail as large as 3/4 inch in diameter also was reported in Littleton…near Parker…and near Buckley Air Force Base. Hail to 7/8 inch was measured near Sheridan and Cheery Creek Reservoir.

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In 1904…a thunderstorm during the early morning of the 3rd turned into widespread general rain…which continued into the early afternoon of the 4th.  Rainfall totaled 2.04 inches.

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In 1878…a “waterspout” or cloudburst of rain was sighted up the South Platte canyon at around noon.  The resulting high waters on the South Platte River slightly damaged a railroad bridge in the city.

In 1937…a trace of snow fell in downtown Denver where rainfall totaled 0.25 inch.  Minimum temperature of 34 degrees was a record low for the date.  Northeast winds were sustained to 22 mph.

In 1951…the start of the second shortest snow-free period on record…109 days…occurred with the last snow of the season…a trace…on the 3rd.  The first snow of the next season occurred on September 21st when 4.2 inches of snow fell at Stapleton Airport.

In 1954…a microburst produced brief sustained winds of 40 mph with gusts as high as 64 mph at Stapleton Airport.

In 1956…the failure of the Georgetown dam caused downstream flooding on clear creek at Idaho Springs and Golden.

In 1976…funnel clouds were sighted near Brighton…Erie…and Dacono…all north of Denver.  A tornado touched down briefly 1 1/2 miles east of Lafayette.  Another tornado touched down briefly at Hyland Hills Golf Course in Westminster.  No damage was reported.

In 1983…severe thunderstorms during the afternoon produced 3/4 inch hail in south Denver…golf ball size hail 5 miles west of Parker…1 1/4 inch hail in Littleton…1 1/2 inch hail in south Aurora.

In 2001…hail as large as 1 inch in diameter fell 17 miles north of Bennett in Adams County.

In 2005…snow was mixed with rain for nearly an hour at Denver International Airport during mid to late morning. The temperature at the time was 45 degrees.  Precipitation totaled 0.36 inch for the day.  Northwest winds gusted to 37 mph.

In 2008…a severe thunderstorm produced large hail…up to 1 3/4 inches in diameter in Arvada…a northwest suburb of Denver.  Several vehicles were damaged.  In addition…a severe thunderstorms produced hail to 1 inch in diameter… 10 miles northeast of manila…east of Denver International Airport.

In 2015…severe thunderstorms broke out across Boulder… Denver…Elbert…Jefferson and southern Larimer Counties. Two large and long lived tornadoes developed near Berthoud and near Simla. The tornado that occurred along the Boulder and Larimer county line. It first touched about 3 miles south of Berthoud…and then tracked to the west/northwest and lifted about 6 miles southwest of Berthoud. The majority of the damage was EF1…with some areas of EF2… and a few small areas of EF3. At least 25 homes between Longmont and Berthoud were damaged; three of them destroyed. No injuries were reported as the winds tore apart homes and rolled vehicles. The EF3 rating is defined as maximum winds estimated at 135 to 140 mph. The path length was 6 miles long with a width of one quarter mile at times. Large hail from quarter to tennis tennis ball size was observed. The largest hail occurred in northeast Boulder County. The hail damaged cars and homes; breaking windows and windshields. In addition… numerous roads were closed along the Larimer and Boulder county line due to flash flooding. Just west of Berthoud… 3.47 inches of rain had fallen. At Denver International Airport…only 0.01 inches of rainfall was recorded… with a peak wind gust to 35 mph from the northeast.

In 2020…severe thunderstorms produced intense wind gusts across parts of Adams and Denver counties. A peak wind gust of 64 mph was observed near Bennett…with a gust to 58 mph observed at Denver International Airport.

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In 1965…lightning and an 18-hour rain storm damaged streets and roads and telephone and power lines across metro Denver.  Precipitation totaled 2.77 inches at Stapleton International Airport where the visibility was reduced to 3 miles at times from pre-frontal thunderstorms and heavy upslope rains.

In 1998…a late season snow storm struck the Front Range foothills.  Up to 5 inches of snow fell in Coal Creek Canyon.  Light snow also fell over western sections of metro Denver and briefly at Denver International Airport. Snow covered the grass at the Denver federal center in Lakewood before melting around mid-morning on the 5th. No snow fell at the site of the former Stapleton International Airport.  Several temperature records were set.  High temperatures of 47 degrees on the 4th and 49 degrees on the 5th were record low maximums for their respective dates.  Minimum temperature of 34 degrees on both the 5th and 6th were record lows for those dates.

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In 1864…high water on the west fork of clear creek caused a small dam near empire to fail…which destroyed several downstream bridges.

In 1885…a windstorm during the afternoon and early evening produced south to southwest winds at sustained speeds up to 42 mph.

In 1937…a trace of snow fell in downtown Denver.  This was the latest snowfall of record at the time.  Light rain and snow were mixed around mid-day.  Precipitation totaled only 0.01 inch.  North winds were sustained to 20 mph.

In 1941…hail of unknown size fell on the city.

In 1961…lightning struck and injured an airman outside a base classroom at Lowry Air Force Base.  Funnel clouds were sighted near Frederick and firestone north of Denver.  The one near Frederick briefly touched down in an open field but caused no damage.  Heavy rain and hail hit the Fort Lupton area causing damage to crops.  Heavy rain in Frederick added to the flood damage of the 3rd.  A pilot reported a funnel cloud that touched down briefly and then dissipated south of Castle Rock.

In 1965…a lightning-caused fire destroyed a mountain home near Rollinsville.

In 1988…a tornado touched down 5 miles east of Lafayette near I-25 and stayed on the ground for 15 minutes.  The twister hit a campground…demolishing one trailer and damaging six others…along with 4 cars.  The rope-like funnel also blew down fences…signs…and electrical boxes. The twister moved a 1500-pound hay wagon 150 feet.  Total damage to the campground was estimated at 50 thousand dollars.  Another tornado touched down between Broomfield and Lafayette…staying on the ground for about 20 minutes. The twister hit a subdivision…unroofing one abandoned house and causing minor damage to a dozen others.  A four- car garage and three barns were destroyed.  At one location a chain link fence…a satellite dish…and a shed were destroyed…while the deck and garage of the house were damaged.  A grain storage tank was moved 200 feet.  There were reports of boards being blown through walls; one came through a kitchen.

In 1992…lightning struck a 15-year-old boy…causing minor injuries…in Adams County 6 miles north-northeast of Stapleton International Airport.  Thunderstorm winds gusted to 63 mph at Jefferson County airport near Broomfield…to 58 mph at the u.s. atomic energy commission’s facility at rocky flats…to 58 mph in Thornton…and to 48 mph at Stapleton International Airport where 1/8 inch diameter hail fell.

In 1996…strong microburst winds up to 60 mph damaged several trees in Boulder…snapping large branches 1 to 2 inches in diameter.

In 1997…a woman was struck by lightning as she was walking to her car in Nederland.  The lightning bolt apparently struck a nearby power line and arced into her left hand. She received minor injuries.

In 2014…severe thunderstorms broke out across parts of Arapahoe…Douglas…Elbert and Jefferson counties… Impacting areas generally southwest and south of Denver. The storms produced large hail…from quarter to golfball size.

In 2015…severe thunderstorms produced hail up to 1 1/2 inches in diameter in Castle Rock and hail up to 1 inches in diameter…southwest of Byers. At Denver International Airport…0.99 inches of rainfall was recorded. A peak wind gust to 35 mph from the southwest as also observed.

In 2017…an intense thunderstorm produced damaging downburst winds which snapped a power pole near the interchange of Interstate 70 and US 36. A weak short-lived landspout also touched down south of I-70 near Bennett and tossed around some lawn furniture.

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In 1977…lightning caused several power outages and moderate damage to a railroad building.

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In 1954…thunderstorm winds at speeds of 50 mph with gusts as high as 59 mph briefly reduced the visibility to 1 mile in blowing dust at Stapleton Airport.

In 1967…the public reported golf ball to 1 3/4 inch diameter hail in the city…3 miles west-southwest of Stapleton International Airport.  The amount of damage was unknown. Thunderstorm winds gusted to 46 mph at Stapleton International Airport.

In 1981…hail to 3/4 inch in diameter was reported in east Denver.

In 1990…golf ball size hail was reported near Strasburg on I-70 east of Denver.

In 1991…a tornado was spotted by national weather service personnel and weather spotters…14 to 17 miles northeast of Stapleton International Airport.  A funnel cloud was sighted over south Aurora just east of Buckley Field…and a tornado was spotted just east of Watkins.  No damage was reported. Thunderstorms moved through Aurora and dropped hail up to 1 inch in diameter.  The storms also produced heavy rain… Up to 1 inch in 30 minutes…causing flooding of streets. Water was reported hood deep…stranding motorists.  Water covered fire hydrants at some intersections.

In 1995…a waterspout sighted over Standley Lake in northern Jefferson County…quickly dissipated once it reached shore. A brief tornado…which was momentarily visible by a dust debris cloud on the ground…damaged the roof of a house in Westminster.  A funnel cloud was sighted just south of Lafayette.  Hail from 3/4 to 1 1/4 inches in diameter fell over north Boulder.  Thunderstorm outflow produced north wind gusts to 44 mph at Denver International Airport.

In 1997…a tornado touched down near baseline reservoir just east of Boulder.  The tornado struck a home…tearing off part of the roof.  A storage building nearby was nearly leveled and 5 trees were uprooted.  The twister then moved onto baseline reservoir…forming a huge waterspout.  Several recreational vehicles and a boat dock were also damaged. A nearly stationary line of thunderstorms dumped 4.60 inches of rain on portions of Thornton.  Extensive flooding of streets and underpasses and other low lying areas was reported.  Several businesses were flooded and basements in the area were damaged.  Rainfall totaled 1.02 inches at Denver International Airport and 1.24 inches at the site of the former Stapleton International Airport.  Large hail…up to 1 3/4 inches in diameter…fell over the city of Denver with 3/4 inch hail measured in Littleton and near Henderson.

In 1999…high winds developed for a brief time in and near the foothills of Boulder.  The Gamow Tower on the University of Colorado campus recorded a wind gust to 87 mph.  Winds peaked to 71 mph atop Niwot Ridge near the continental divide west of Boulder.

In 2003…a small tornado touched down near Strasburg…but did no damage.

In 2012…severe thunderstorms broke late in the evening… striking areas hardest from Denver southward. Locations impacted by the storms included but were not limited to: Aurora…Castle Rock…Centennial…Highlands Ranch…Lone Tree… Parker and Surrey Ridge. The storms produced a barrage of large hail…damaging straight line winds…flash flooding and several short lived tornadoes. The hail ranged in size from 1 to 2 inches in diameter…and caused extensive damage to homes and automobiles. The hail inundated the roadways with several inches of hail in Douglas County. Consequently… snow plows had to be called out to clear the roadways. The combination of torrential hail and heavy rain produced flash flooding in parts of Elbert…Douglas and Arapahoe Counties…as thunderstorms brought up to 3.35 inches of rain to some areas within 90 minutes. In Aurora…Picadilly Road was closed from flooding north of 6th Avenue. A water rescue took place on South Gun Club Road in Arapahoe County…where floodwaters were rushing to depth of 3 feet. Flash flooding forced the closure of several streets and roads from Parker south to The Pinery…where the floodwaters inundated the roadway with up to 2 feet in several locations.  At Centennial Airport…a historic B-17 Flying Fortress suffered extensive damage as hailstones as large as ping pong balls struck the aircraft. Although the airframe itself did not require repair…the fabric-covered ailerons and elevators were extensively damaged. The hail came straight down and punched holes in the fabric-covered control surfaces. The aircraft landed just hours before the storm hit to participate in a weekend tour stop.  Lightning also struck two homes…one in Lakewood and the other in Parker. Straight line winds downed trees and power lines in Aurora. As a result…scattered electrical outages affected around five thousand residents.  At Denver International Airport… 0.61 inches rainfall was recorded along with a peak wind gust of 41 mph.

In 2016…powerful thunderstorms fired up along the Urban Corridor and produced damaging hail…strong outflow winds… heavy rain and lightning. Golf-ball size hail in Highlands Ranch caused extensive damage including broken windows on homes and windshields on vehicles. Heavy rainfall…also produced street flooding. In and around Highlands Ranch… anywhere from 2.3 to 2.8 inches of rainfall was observed… with 1 to 1.5 inches around metro Denver. At Denver International Airport…0.38 inches of rainfall was recorded.

In 2020…a combination of an upper level trough moving northwest across the state…coupled with a strong surface pressure gradient…led to numerous reports of high wind gusts across the Denver the surrounding region. Most of the wind damage occurred with the passage of a rare derecho; a large fast-moving complex of thunderstorms with powerful straight-line winds. In addition…strong wind gusts from 59 to 71 mph not associated with the derecho… occurred prior to and following the passage of this system. By midday the derecho…moved over the mountains…and then rapidly northeast across the I-25 corridor by mid afternoon. Wind gusts from 60 to 80 mph were common with a few gusts exceeding 90 mph. The highest gust observed was 110 mph…at the Winter Park Ski area…around 12000 feet. Xcel Energy reported more than 208000 customers lost power because of the storm statewide. Widespread tree damage was reported. The intense wind toppled a billboard that crashed onto Denver bakery. Two delivery trucks parked nearby were heavily damaged. Two injuries occurred in Denver…one seriously. A man and his nine-year-old daughter were injured by a fallen tree. They were standing in front of a family members house when the incident occurred. The tree impaled the father through his back and he required several surgeries. His daughter sustained cuts and bruises that required stitches. Southwest winds gusted to 78 mph at Denver International Airport…with a peak gust to 76 mph at Centennial Airport.

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In 2004…a brief hot spell produced 3 temperature records. High temperatures of 95 degrees on the 6th and 98 degrees on the 7th were record maximum temperatures for the dates. Low temperature of 68 degrees on the 7th was a record high minimum for the date.

In 2007…an unusually strong storm system brought very strong winds to the Front Range foothills and urban corridor. Peak gusts included:  92 mph at Boulder…85 mph…2 miles southwest of Boulder…83 mph…10 miles south of Boulder and 55 mph at Denver International Airport.  High winds forced the closure of Mt. Evans Road and Trail Ridge Road.  Several trees were uprooted across the urban corridor.  In Aurora… The driver of a car was injured when some building material blew off the Fitzsimmons complex.  The debris landed on the car and knocked the driver unconscious.  The wind forced the cancellation of 60 flights at Denver International Airport. Xcel reported outages in Boulder…Denver…Lakewood and Longmont.

In 2012…severe thunderstorms broke late in the evening… Striking areas hardest from Denver southward. Locations impacted by the storms included but were not limited to: Aurora…Castle Rock…Centennial…Highlands Ranch…Lone Tree… Parker and Surrey Ridge. The storms produced a barrage of large hail…damaging straight line winds… Flash flooding and several short lived tornadoes. The hail ranged in size from 1 to 2 inches in diameter…and caused extensive damage to homes and automobiles. The hail inundated the roadways with several inches of hail in Douglas County. Consequently… Snow plows had to be called out to clear the roadways. The combination of torrential hail and heavy rain produced flash flooding in parts of Elbert…Douglas and Arapahoe counties…as thunderstorms brought up to 3.35 inches of rain to some areas within 90 minutes. In Aurora…Picadilly Road was closed from flooding north of 6th Avenue. A water rescue took place on South Gun Club Road in Arapahoe County…where floodwaters were rushing to depth of 3 feet. Flash flooding forced the closure of several streets and roads from Parker south to the Pinery…where the floodwaters inundated the roadway with up to 2 feet in several locations. At Centennial Airport…a historic B-17 Flying Fortress suffered extensive damage as hailstones as large as ping pong balls struck the aircraft. Although the airframe itself did not require repair…the fabric-covered ailerons and elevators were extensively damaged. The hail came straight down and punched holes in the fabric-covered control surfaces. The aircraft landed just hours before the storm hit to participate in a weekend tour stop. Lightning also struck two homes…one in Lakewood and the other in Parker. Straight line winds downed trees and power lines in Aurora. As a result…scattered electrical outages affected around five thousand residents. At Denver International Airport… 0.61 inches rainfall was recorded along with a peak wind gust of 41 mph.

Colorado’s famously highly variable weather seems to showcase itself during the month of May when a variety of weather conditions can be seen.  This provides a prime opportunity for photos of everything weather to flora to fauna.

The month of May can bring extremes.  Snow is not entirely uncommon during the month but more common is severe weather, particularly in the latter half of the month.  Thunderstorms become more frequent and their associated hazards – lightning, wind, hail and tornadoes – are usual visitors.  Providing additional subjects for pictures are the emerging spring flowers and our abundant wildlife.

• Slideshow updated May 28, 2026. To learn more about how to send your photo to us for inclusion in the slideshow, see below the slideshow.

Showcasing images captured by ThorntonWeather.com readers as well as some of our own, our monthly slideshow covers the entire gamut of weather-related imagery.

Sunsets, sunrises, wildlife and of course every type of weather condition are vividly depicted in images captured from yours and our cameras.

What is missing in the slideshow above?  Your photo!

Our monthly photo slideshow is going to feature images that we have taken but more importantly images that you have captured.  The photos can be of anything even remotely weather-related.

Landscapes, current conditions, wildlife, pets, kids.  Whimsical, newsy, artsy.  Taken at the zoo, some other area attraction, a local park, a national park or your backyard.  You name it, we want to see and share it!

Images can be taken in Thornton, Denver or anywhere across the extraordinary Centennial State.  We’ll even take some from out of state if we can tie it to Colorado somehow.

We’ll keep the criteria very open to interpretation with just about any image eligible to be shown in our slideshows.

What do you win for having your image in our slideshow?  We are just a ‘mom and pop’ outfit and make no money from our site so we really don’t have the means to provide prizes.  However you will have our undying gratitude and the satisfaction that your images are shared on the most popular website in Thornton.

To share you images with us and get them included in the slideshow just email them to us or share them with ThorntonWeather.com on any of the various social media outlets.  Links are provided below.

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Severe weather in spades is evident on our look back at Denver weather history this week. Notable is an F1 tornado in 1990 that moved through the Northglenn and Thornton area that damaged buildings, cars and trees.

From the National Weather Service:

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In 2023…smoke and haze from massive wildfires in Canada significantly impacted air quality and visibility across Denver and the rest of northeast Colorado.

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In 2002…lightning sparked a wildfire near Deckers. Extremely dry conditions and very strong winds the following day allowed the fire…known as the Schoonover…to consume 3850 acres before it could be contained. Thirteen structures were destroyed…including 4 homes…resulting in 2.2 million dollars in damage.

23-24

In 2002…a pacific storm system brought much needed snow to the mountains and foothills with a mix of rain and snow on the plains. The most snow fell from central Jefferson County northward. Snow totals included: 13 inches in Coal Creek Canyon…11 inches near Evergreen and atop Gold Hill… 10 inches near Blackhawk and Conifer and atop Crow Hill… 9 inches near Rollinsville…and 8 inches near Genesee and Golden. Rain was mixed with snow across the city. Precipitation totaled 0.61 inch at Denver International Airport. Snowfall was less than an inch at the site of the former Stapleton International Airport. The storm brought unseasonably cold air to metro Denver. Three temperature records were set. Low temperature of 31 degrees on the 23rd was a record minimum for the date…as was the low of 32 degrees on the 24th. The high temperature of only 48 degrees equaled the record low maximum for the date.

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In 1953…a microburst caused a brief wind gust to 55 mph at Stapleton Airport.

In 1957…walnut size hail…1 1/2 inches in diameter…fell in east Denver. Only 1/4 inch hail was measured at Stapleton Airport.

In 1958…rainfall totaled 1 to 2 inches across metro Denver. Rainfall was only 0.37 inches at Stapleton Airport.

In 1974…a tornado was observed briefly near Watkins. No damage was reported.

In 1980…strong gusty winds of at least 60 mph damaged buildings in parts of Denver. Several buildings were unroofed in Sheridan. The flying debris damaged other structures. Strong microburst winds gusted to 52 mph at Stapleton International Airport.

In 1991…a tornado touched down briefly in open country near Bennett. No damage was reported.

In 1994…weather spotters reported 2 funnel clouds over Aurora and a short-lived waterspout on Cheery Creek Reservoir.

In 1997…hail to 1 inch in diameter fell in Broomfield with 3/4 inch hail measured in Boulder.

In 1998…a tornado struck a wooden hangar at the Aurora airpark. The hangar collapsed…damaging a car and a single engine plane parked inside. An adjacent steel hangar sustained only minor damage. The tornado moved northeast…hopped I-70…and touched down again in an open field. Earlier…a weak tornado touched down briefly in an open field 10 miles southeast of Buckley Field.

In 2003…severe thunderstorms produced large hail over northern and southern metro Denver. Hail as large as 2 3/4 inches in diameter was measured 10 miles northwest of Hudson and to 2 inches in diameter 10 miles northeast of Fort Lupton. One inch diameter hail fell in Fort Lupton. Hail to 1 inch in diameter fell near Parker and to 3/4 inch near Franktown.

In 2004…severe thunderstorms moved across northwest and north metro Denver. Hail as large as 1 inch in diameter fell in Broomfield and Thornton with 3/4 inch hail measured near Arvada and Hudson and in the city of Denver.

In 2005…severe thunderstorms produced hail as large as 1 inch in diameter in Arvada and the city of Denver.

In 2014…a severe thunderstorm in Lakewood produced hail… Up to 1 inch in diameter.

In 2016…a long-lived supercell formed over south Denver and tracked across northeast Adams and continued to produce severe weather as into moved into Yuma County. The length of its path was approximately 121 miles. The storm produced hail up to 1.5 inches in diameter in southeast Denver. As it moved across northeast Adams County…several power poles were sheared off at the base by straight-line winds to 80 mph southwest of Leader. The damage path became more extensive as the storm moved into the northeast plains of Colorado. At Denver International Airport…1.15 inches of precipitation fell which set a new daily precipitation record. The storm produced heavier rainfall on one to two inches east of Denver…with over 4 inches in central Arapahoe County.

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In 1996…a late spring snowstorm dumped 4 to 10 inches of snow over the Front Range foothills. Conifer picked up 10 inches of new snow; aspen springs…9 inches; and central city…8 inches. The sticky…heavy snow clung to power lines and pulled tree branches down…causing power outages to about 1200 homes in the conifer area. It took up to 6 hours to restore power to some residences. Lightning struck a telephone data cabinet in conifer on the 25th…which knocked out phone service to about 1500 customers. Widespread rain fell across metro Denver… Where rainfall totaled 2.07 inches at the site of the former Stapleton International Airport and 1.66 inches at Denver International Airport where north winds gusted to 24 mph on the 26th.

In 2010…high winds preceding a cold front… Swept across the Front Range foothills and urban corridor. In Aurora… The wind damaged the roof of Rangeview High School. In Conifer and Denver…the wind downed trees and power lines and caused several brief outages. The downed power lines also caused several cars to catch fire in the vicinity of 1590 Cook St. in Denver. Peak wind gusts included: 82 mph at Highlands Ranch…67 mph… 4 miles east of Franktown and Longmont; 65 mph in Boulder…64 mph in Centennial and Denver International Airport…62 mph near Parker and 60 mph in Arvada.

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In 1877…lightning killed one person in west Denver and struck several houses. The bolt struck the house of the “home laundry” stunning the occupants and killing a lady who was holding one of her grand children in her arms. The child escaped unhurt. The lightning also struck the top of a tree in front of the house and partially peeled the bark off the tree. Lightning struck a church in the Evans addition and another tree in east Denver. Lightning struck the switch room at the telegraph office where the operator saw small balls of lightning pass across the room to the stove. The thunderstorm pelted the city with only pea size hail. Precipitation from the storm totaled 0.40 inch in downtown Denver.

In 1880…light rain all afternoon totaled only 0.24 inch in the city…but was valuable to stockmen and farmers due to the very dry…parched weather conditions on the plains.

In 1965…a tornado was sighted by a pilot 30 miles south southeast of Denver. No damage was reported. Another pilot reported 3/4 inch hail 30 miles east of Denver. The state patrol reported that a man was killed when a fierce gust of wind swept him from the back of a pick-up truck in northwest Douglas County. The man was holding a mattress in the bed of the truck.

In 1974…a microburst wind gust to 53 mph was recorded at Stapleton International Airport. A pilot reported a tornado 20 miles east of Denver.

In 1976…lightning struck a home in Boulder…shattering 2 large trees and damaging a television set.

In 1997…hail as large as 1 3/4 inches in diameter fell near Watkins. Hail to 3/4 inch in diameter fell in Broomfield and near Lockbuie.

In 2000…3/4 inch diameter hail fell at Cheery Creek Reservoir in Aurora. Thunderstorm winds gusted to 51 mph at Denver International Airport where small hail fell.

In 2006…a severe thunderstorm produced an estimated wind gust to 70 mph in Hudson. The strong winds damaged the roof of a home. A thunderstorm produced southwest wind gusts to 54 mph at Denver International Airport.

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In 1950…a major storm dumped 10.0 inches of snowfall downtown and 10.7 inches at Stapleton Airport where northwest winds gusted to 30 mph on the 25th. The storm caused extensive damage to utility wires and trees which were in full leaf. A daily record minimum temperature of 31 degrees occurred on the 25th. This was the coldest temperature on this date in 79 years and for so late in the season.

In 1989…a late season snow storm dropped snow as low as 6 thousand feet along the Front Range. Most places in the foothills had 2 to 5 inches of snow. Overnight rainfall totaled 0.33 inch at Stapleton International Airport where north winds gusted to 37 mph on the 25th.

In 1994…lightning struck a television transmitter on Lookout Mountain near Golden and burned out a switcher…which disrupted cable service for 2 hours.

26

In 1897…apparent post-frontal north winds were sustained to 42 mph with gusts as high as 48 mph.

In 1942…the all-time highest recorded temperature in May…95 degrees…occurred.

In 1978…two children were struck and killed by lightning on a junior high school playground in Parker.

In 1987…1 inch diameter hail fell near Boulder and Bennett. The hail was fairly soft and caused no damage.

In 1993…dry thunderstorms produced wind gusts to 81 mph at Jefferson County airport near Broomfield. Several trees were blown down by the strong winds. Microburst winds gusted to 51 mph at Stapleton International Airport.

In 1995…a woman was injured in Littleton when the car she had just entered was struck by lightning. All of the windows in the car were blown out by the strike. A funnel cloud was sighted near Littleton.

In 2000…a strong microburst wind gust to 92 mph flipped a small airplane on its back and blew a dc-3 loose from its moorings…which allowed it to roll onto a grassy field at Front Range airport near Watkins.

In 2010…severe thunderstorms pounded parts of the urban corridor with very large hail…heavy rain… Damaging winds and a tornado. The hail…ranging in size from 1 inch to 2 3/4 inches in diameter…struck Brighton… Commerce City and northeast Denver the hardest. The storms continued to spread destruction to the north and east…impacting byers…Hudson… Deer Trail and Prospect Valley. The combination of hail and wind stripped the bark and branches from trees. Numerous accidents were reported as the hail accumulated up to a foot deep. Snowplows were called out to clear the roadways. Flash flooding occurred along State Highway 52 between Hudson and Keenesburg…and forcing the closure of the highway. Widespread crop damage was also reported as the area was inundated with up to 18 inches of water. Extensive damage to homes…businesses and automobiles was reported with the damage estimated to be around 70 million dollars. A tornado touched down near Denver International Airport…but did no damage. Lightning struck a child in Commerce City while she was watching television. She suffered minor injuries to her leg. At the Rocky Mountain Arsenal Wildlife Refuge…a lightning strike killed a bison. At Denver International Airport…only 0.01 inch of rainfall was observed… Along with a peak wind gust to 48 mph from the southeast.

In 2016…severe thunderstorms produced hail up to one inch in diameter near Castle Rock…The Pinery and Watkins.

In 2019…severe thunderstorms broke out across parts of Adams…Arapahoe…Denver…and southern Weld counties during the late afternoon and early evening. The hail ranged from 1 to 1 1/2 inch in diameter. At Denver International Airport…up to 3 inches of hail accumulated on runway surfaces. Consequently…dozens of flights were either delayed or cancelled so runways could be cleared and aircraft inspected for hail damage. A peak wind gust to 44 mph was observed from the west at Denver International Airport…with 0.65 inch of rainfall.

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In 1995…a cool period with light morning showers and moderate to heavy afternoon showers and thunderstorms pushed rivers already swollen from mountain snow melt over their banks causing minor flooding. Streams and rivers such as the South Platte and Boulder creek flooded meadowlands…bike paths…roads near streams…and other low lying areas. No significant property damage was reported and crop damage was unknown. Rainfall totaled 1.79 inches at the site of the former Stapleton International Airport and only 1.51 inches at Denver International Airport.

27

In 1874…an apparent thunderstorm gust front reached the city at 6:40 pm. Strong southwest winds sustained to 48 mph for a few minutes produced large columns of dust in the city and on the prairie. There was no rain in the city.

In 1942…a duststorm swept into the city…but no damage was reported. West winds were sustained to 23 mph.

In 1953…a heavy hailstorm caused an estimated 100 thousand dollars damage across metro Denver. Larger than golf ball size hail fell in Westminster and north Denver. Only 1/8 inch hail was measured at Stapleton Airport.

In 1955…west-northwest winds at 35 mph with gusts as high as 58 mph briefly reduced the visibility to 1/2 mile in blowing dust at Stapleton Airport.

In 1981…lightning damaged power lines west of Lakewood and blew up a transformer at the Denver federal center. Hail 1 to 1 1/2 inches in diameter was reported in Lakewood and on I-25 south of Denver.

In 2001…hail as large as 3/4 inch in diameter was measured near Commerce City.

In 2003…hail to 3/4 inch in diameter fell near central city.

In 2006…unusually warm weather for late May produced two temperature records. The high temperature of 93 degrees was a record maximum for the date. The low temperature of 59 degrees equaled the record high minimum temperature for the date. Both previous records occurred in 1895.

28

In 1884…a thunderstorm apparently produced large hail. The hail stones were noted as unusually large…but the diameter of the stones was not measured. The hail fell for only 5 minutes. Precipitation from the storm was only 0.05 inch.

In 1898…heavy thunderstorm rainfall totaled 1.74 inches in downtown Denver. Hail of unknown size accompanied the storm.

In 1981…a woman in Aurora was struck and killed by lightning. Another bolt injured a boy on a bicycle at about the same time a short distance away. About half an inch of rain in 20 minutes caused street flooding in the area. A tornado touched down for about 2 minutes some 3 miles north of Stapleton International Airport.

In 1982…severe thunderstorms produced golf ball size hail in southeast Denver…Aurora…and Strasburg. The large hailstones undoubtedly damaged some cars in the area. At Stapleton International Airport…only 1/2 inch diameter hail was measured.

In 1991…golf ball size hail fell in Brighton. No damage was reported. Later…hail ranging in size from 3/4 inch to 1 1/2 inches in diameter fell over southwestern sections of metro Denver. In some areas…hail piled up a few inches in depth.

In 1994…thunderstorm wind gusts to 65 mph damaged 16 small airplanes and a hangar at centennial airport.

In 2001…severe thunderstorms produced large hail across metro Denver. Hail as large as 1 inch in diameter fell in Lakewood…Wheat Ridge…northwest Denver…near Watkins… Bennett…and Keenesburg. Hail 3/4 inch or larger fell in Brighton. Thunderstorm winds gusted to 58 mph at Denver International Airport. A small tornado (f0) touched down near Bennett…but did no damage.

In 2019…a severe thunderstorm broke out over metro Denver during the overnight hours. Some damage was reported to cars and vegetation. The hail ranged in size 7/8 inch to 1 1/4 inch in diameter. Broadcast media reported damage to 16 different greenhouses around Denver; seven experienced significant damage. In addition…two separate storms passed across Denver International Airport. The hail accumulated on the runways but no damage to aircraft was reported.

29

In 1934…the low temperature dipped to only 66 degrees…the all-time record highest minimum temperature for the month of May.

In 1958…a microburst caused a brief wind gust to 56 mph at Stapleton Airport.

In 1964…heavy rain caused flooding in the Harvey Gulch area of southeast Denver. The high water damaged homes… Businesses…streets…and bridges. At Stapleton International Airport…1.33 inches of rain were measured with 1.76 inches total rainfall on the 29th and 30th. The heavy rain during the last week of the month was the first significant precipitation since April 3rd.

In 1967…3/4 to 1 inch diameter hail stones fell in the city of Denver…but caused no reported damage. Hail as large as 3/4 inch was measured at Stapleton International Airport.

In 1975…the heaviest last snowfall of the season occurred when 5.6 inches of snow were measured at Stapleton International Airport. Rain all day on the 28th changed to snow on the 29th and accumulated to a depth of 4 inches on the ground. Northwest winds gusted to 31 mph. Precipitation (rain and melted snow) on the 28th and 29th totaled 1.48 inches.

In 1982…one man was killed and two others injured by a lightning strike as they stood under a tree in the city of Denver’s Washington Park.

In 1987…7/8 inch diameter hail fell near Castle Rock.

In 1990…thunderstorms over metro Denver produced several small funnel clouds and two small tornadoes. The first tornado (f0) touched down in northwest Denver and caused roof damage to a house and snapped off the tops of several trees. A second tornado (f1) touched down in Northglenn and moved into Thornton damaging a group of self storage garages…several vehicles…a wooden fence…several trees… And the roof of an auto parts store. No injuries were reported. The storms also caused minor street flooding across northern and western sections of metro Denver. Rainfall totals ranged from 1 to 3 inches. Lightning started a small fire at a home in northwest Denver. The fire was confined to the front rooms and was quickly extinguished. Snow plows were used to clear 2 to 4 inches of pea to marble size hail from a stretch of U.S. Highway 285 in Turkey Creek Canyon. Lightning felled a tree in northeast Denver…while strong winds snapped off several large tree limbs in the same area. Thunderstorm rainfall totaled 0.82 inch at Stapleton International Airport where southwest winds gusted to 30 mph.

In 1991…lightning struck a 13 year old boy in a field in Fort Lupton. The boy was in critical condition in an area hospital for 2 days before recovering.

In 1995…lightning struck a soccer goal post and injured 6 adults viewing a soccer game in Arvada. Although no one received a direct hit from the lightning…all escaped with only minor injuries…except one woman who was hospitalized.

In 1996…large hail…3/4 to 1 1/2 inches in diameter… Struck Lakewood and west Denver. Lightning sparked a small fire when it struck an oil storage tank 5 miles west of Brighton.

In 2001…lightning sparked a fire in an apartment complex in Aurora…forcing the evacuation of 24 units. Most of the fire damage was confined to the attic. Damage was estimated at 100 thousand dollars.

In 2004…a man and his son were struck by lightning while practicing on the driving range at the meadows golf club in southwest metro Denver. The father was killed by the bolt…and his 16 year old son seriously injured. Three other people standing nearby received only minor injuries.

In 2010…hail up to 7/8 inch in diameter was reported in Broomfield.

In 2017…an isolated thunderstorm produced hail up to 7/8 inch in diameter near Centennial.

29-1

In 1894…heavy rain combined with snowmelt runoff caused widespread flooding over the South Platte River basin. Rainfall was heaviest in the foothills where 5 to 8 inches were measured over the 4 days. Heavy rainfall west of Boulder flooded mining towns and damaged mining properties. In the canyons above Boulder…railroads and roads were washed out along with many bridges. The floodwaters spread into central Boulder and covered a wide area from university hill north to near Mapleton Hill to a maximum depth of 8 feet. Many houses were swept away…and every bridge in Boulder was destroyed. A few people…trapped in their homes by the floodwaters… Had to be rescued. However…the gradual rise of the flood waters resulted in only one death. Boulder creek spread to a width of nearly one mile in the pasture land to the east of Boulder. Extensive flooding on left hand creek north of Boulder washed away railroad and wagon bridges. The heavy cloudbursts caused flooding on bear creek…which washed away bridges…railroad tracks…and structures and destroyed the canyon roadway. Morrison sustained the heaviest flood damage on bear creek. In Denver…rainfall totaled only 1.50 inches on the 30th and 31st…but the heavy rainfall on upstream tributaries of the South Platte River caused the river to rise as much as 10 feet above the low water mark in the city…which caused some flooding of pasture land downstream to a depth of 6 feet near Brighton.

30

In 1875…a windstorm lasting almost all day produced sustained winds to 42 mph.

In 1935…southeast winds sustained to 29 mph with gusts to 34 mph produced a moderate duststorm during the afternoon.

In 1938…heavy thunderstorm rain and hail pummeled downtown Denver during the evening hours. Rainfall accumulated to 1.63 inches. Hail accumulated to a depth of 18 inches.

In 1948…a localized thunderstorm caused flooding on sand creek in Aurora and northeast Denver. Rainfall was only 0.49 inch in downtown Denver where light hail also fell.

In 1963…a golfer died of injuries received when struck by lightning on a golf course southwest of Denver. A warehouse in Denver was damaged and its contents destroyed by a lightning-caused fire.

In 1967…up to 4.00 inches of rain in Lakewood and Wheat Ridge caused flooding of roads and basements. Water was several feet deep in some yards. Many streets were temporarily closed. Hail as large as 1 inch in diameter fell in Wheat Ridge. Hail piled up to 2 feet deep in some low lying areas of east and southeast Denver. Snowplows were employed to remove the hail. Stapleton International Airport…where west winds gusted to 39 mph…received 1.51 inches of rain and hail…which forced the closure of the runways for an hour. Hail stones to 3/4 inch in diameter were measured at Buckley Field. A funnel cloud was sighted near south Wadsworth Blvd. And bear creek. A tornado touched down briefly in the vicinity of 60th and 62nd avenues near north Washington Street. The storm uprooted trees and damaged one building. Doors were ripped from a business house…widely scattering irrigation pipe. In addition…a total of 3 funnel clouds were sighted in that area.

In 1970…hail up to 1 inch in diameter fell at Stapleton International Airport.

In 1976…a single thunderstorm crossed south metro Denver producing a funnel cloud 2 miles south of Arapahoe Road and Broadway. The storm moved over Buckley Field producing a funnel cloud and 1/2 inch diameter hail. As the storm moved northeast of the city…a large tornado touched down near east 59th Ave and tower road and was on the ground for 20 minutes. It demolished a 60-foot-long cinderblock cow shed…tore a wall from a machinery shed…tore shingles off the roof of a farmhouse nearby…and felled 12 trees on one farm. A boy in a feed shed 20 feet from a destroyed building was not injured.

In 1977…3/4 to 1 inch diameter hail fell at or near Stapleton International Airport. One inch to baseball size hail fell in south Denver…damaging some homes and extensively damaging some airplanes at Arapahoe County airport…now centennial airport. Hail covered highways to a depth of 6 to 8 inches in south Denver.

In 1978…two funnel clouds were sighted 5 miles south of Stapleton International Airport. Hail up to 1 1/4 inches in diameter was reported in Wheat Ridge and northwest Denver. Only 1/2 inch diameter hail fell at Stapleton International Airport.

In 1989…golf ball size hail fell at the junction of I-25 and I-225. One inch diameter hail fell in Littleton.

In 1990…a line of severe thunderstorms crossed metro Denver… Producing wind gusts to 60 mph and scattered areas of pea to marble size hail. Small trees and branches were blown down by the strong thunderstorm winds…which also caused minor power outages across southern and eastern sections of metro Denver. The strong winds uprooted a 25- to 30-foot tree in the acres green subdivision of northern Douglas County. The tree blocked a busy street for several hours. A pilot reported hail as large as 1 1/2 inches in diameter covering the ground near the north end of a runway at Stapleton International Airport. Heavy rain caused a rock and mud slide that partially closed the Boulder canyon highway 10 miles west of Boulder. Thunderstorm winds gusted to 41 mph at Stapleton International Airport.

In 2001…lightning ignited a fire which destroyed a luxury home on Bear Mountain near evergreen. Estimated damage was set at 1 million dollars.

In 2003…flash flooding occurred in the Hayman Fire burn area after as much as 1 inch of rain fell in 30 minutes. The heavy rainfall washed out many access roads and closed State Highway 67 between Deckers and west creek. A 3-foot wall of water ran down Fourmile Creek from the YMCA camp at shady brook…damaging one building in the camp and flooding roads. Hail as large as 3/4 inch in diameter fell near Roggen in Weld County.

In 2005…lightning struck as least 20 homes in Westminster. Only minor damage was reported. Severe thunderstorms produced hail as large as 1.25 inches in and near Fort Lupton and hail to 3/4 inch near Indian Hills in Jefferson County.

In 2014…heavy rainfall…nearly 1.2 inches in 30 minutes… Produced localized street flooding in Boulder. The heavy rain coupled with the already swollen creeks from the spring runoff along Boulder Creek resulted in the flooding. Street flooding was reported at 6th St and Canyon Blvd and at Baseline Road. Some cars were stranded in the high water in low lying areas and one person reported being trapped in his vehicle.

In 2024…during the late evening hours…severe thunderstorms moved across Denver as well as the northern and eastern suburbs…including Broomfield…Aurora…and Commerce City. Quarter to baseball sized hail left a large swath of damage. These storms and the resulting hail caused an estimated $1.9 billion in damages. That mostly includes homes…autos…and businesses. The total damage caused makes this second only to the May 8…2017…storm…which was the worst hailstorm in Colorado history.

30-31

In 1935…heavy thunderstorm rains overnight caused flash flooding east of the city on both Kiowa and Bijou Creeks… Resulting in a total of 9 deaths. Most of the damage was on Kiowa Creek where there were more structures. The water rose rapidly during the storm…ripping houses and stores from their foundations and sweeping them downstream. Precipitation in Denver totaled only 0.01 inch. Hail fell in the city for a short time. The hail was very small and caused no damage.

In 1983…a late storm of rain and snow hit the Front Range. Over an inch of rain fell at some spots…and above 7 thousand feet…1 to 5 inches of snow whitened the ground. Some snow flakes even fell in the western suburbs of metro Denver on the night of the 30th.

In 2002…unseasonably warm weather at the end of the month resulted in 3 temperature records. High temperature of 91 degrees on the 30th equaled the record maximum for the date. Low temperature of 61 degrees on the 31st was a record high minimum for the date. High temperature of 93 degrees on the 31st was a record maximum for the date.

As we move further into the severe weather season, we begin to see that transition in our look back at Denver weather history.  There are many more mentions of lightning, wildfires, tornadoes, hail and other season weather conditions.

14-18

In 1996…a period of unusually warm weather resulted in 4 record maximum temperatures in 5 days.  The record high temperatures were 87 degrees on the 14th…89 degrees on the 15th…and 93 degrees on both the 16th and 18th.  The temperature climbed to only 81 degrees on the 17th which was not a record.

16-17

In 1981…a heavy rain storm dumped 1 to 2 1/2 inches of rain across metro Denver.  Rainfall totaled 1.27 inches at Stapleton International Airport where north winds gusted to 38 mph on 17th.

In 1983…a very strong late spring storm dumped heavy snow over the Front Range.  Strong winds with the storm produced blizzard conditions at times.  Sustained winds were 20 to 40 mph with a peak gust to 55 mph at Stapleton International Airport.  The foothills received 1 to 2 feet of snow with 4 to 12 inches along the foothills.  Howling winds whipped the snow into drifts several feet deep…closing schools and highways.  Stapleton International Airport was forced to reduce flight operations…closing 2 of 4 runways and stranding hundreds of travelers.  Most of the damage and inconvenience caused by the storm was in power outages… Which occurred when wind and heavy wet snow caused hundreds of power poles to snap and topple.  About 20 square miles of Denver were blacked out.  Precipitation from the storm totaled 1 to 3 inches.  At Stapleton International Airport… Snowfall totaled 7.1 inches with a maximum snow depth on the ground of only 2 inches due to melting.  The high temperature of 40 degrees on the 17th was a record low maximum for the date.  Due to the heavy moisture content of the storm…widespread street flooding occurred on the 18th when much of the snow melted under the warm May sun and temperatures climbed to a high of 57 degrees.

In 1995…significant moisture and upslope flow caused flooding across metro Denver.  Moderate to heavy rains… Which began on the evening of the 16th…developed in the foothills and spread eastward over metro Denver throughout the night.  The heavy rains brought many creeks and small streams to bankfull or slightly over.  Locations along the foothills received between 3 and 4 inches of rainfall from the storm.  Boulder received 3.60 inches of rainfall for the 24-hour period…causing minor street flooding near small streams.  To the northwest of Boulder…a bridge which crossed Fourmile Creek was washed out.  Numerous rock and mudslides occurred in foothills canyons…closing portions of U.S. Highways 6 and 40 and State Highway 119 for a few hours at a time.  Rocks were piled 6 feet deep on a stretch of State Highway 119 along with Boulders as large as cars on U.S. Highway 6.  A parking lot near a creek in Golden caved in leaving a hole the size of an 18-wheeler.  Rushing water washed out a 50-foot stretch of a road in Westminster. Rainfall totaled 1.75 inches at Denver International Airport…but only 1.42 inches at the site of the former Stapleton International Airport.

17

In 1903…southwest winds were sustained to 42 mph with gusts to 45 mph from an apparent microburst which produced only a trace of rain.

In 1960…hail to 3/4 inch diameter was measured in Thornton. Golf ball size hail fell in Arvada.

In 1972…microburst winds gusted to 51 mph at Stapleton International Airport.

In 1975…hail 1/2 to 3/4 inch in diameter fell over western metro Denver.

In 1978…a small tornado touched down in south Aurora damaging 40 homes…6 to a considerable extent.  One garage was demolished and blown across the street.  Parts of roofs were completely blown away.  Several 2×4-inch boards were blown into the sides of houses.  Another small tornado in Parker damaged two airplanes.  Other funnel clouds were sighted over Northglenn and near Golden.

In 1985…a thunderstorm produced a total of 1.50 inches of rain in Brighton where 0.72 inches fell in 40 minutes. Small hail covered the ground…and there was some street and basement flooding.

In 1987…small hail piled up 4 inches deep in southwest Aurora.  There was also widespread street flooding and a few power outages.  Hail as large as 3/4 inch in diameter fell at Castle Rock.

In 2000…high winds occurred along and east of the Front Range foothills…as a deep surface low pressure center formed over the northeast plains of Colorado.  An amusement park in north Boulder received about 25 thousand dollars in property damage.  Peak wind reports included:  88 mph at the national wind technology center…84 mph in Boulder…and 80 mph at the National Center for Atmospheric Research Mesa Laboratory. A powder keg of severe weather…including tornadoes and thunderstorms producing large hail…damaging winds and heavy rain…occurred over the plains to the northeast of Denver.  The only severe weather reported across metro Denver was 1 inch diameter hail in Littleton.

17-19

In 2017…a strong spring storm dropped across the Great Basin… and then moved eastward across Colorado. Isolated but strong thunderstorms preceded the system on the 17th with hail up to nickel size near Boulder Airport and Brighton. Significant snow fell across the Front Range mountains and foothills over the next couple of days. Along the Interstate 25 Corridor… rain turned to snow on the morning of the 18th…heaviest from around Broomfield northward. The heavy wet snow snapped the limbs of fully leaved trees and caused scattered power outages. A barns collapsed in northeast Loveland. Fifty-five head of cattle were inside the collapsed barn; three were injured and later euthanized. Numerous branches and trees snapped in the foothills. Elsewhere…several scattered smaller power outages were reported. Three to nearly five inches of liquid precipitation occurred…as rain or a mix of rain and snow…fell around Greeley. Storm totals in the Front Range mountains and foothills included: 42.0 inches near Allenspark…41.5 inches near Ward…36 inches at Estes Park… 32 inches near Pinecliffe…30.5 inches northwest of Golden… 30 inches near Nederland…26 inches near Breckenridge…25 inches near Aspen Springs and Bear Lake State Park…14 inches at Aspen Springs…with 9.5 inches near Evergreen. On the west side of the Interstate 25 Corridor…storm totals included: 10 inches near Superior and Louisville…6 to 8 inches in and around Fort Collins…6 inches in Lafayette… 5 inches in Broomfield and Loveland…and 4 inches near Niwot.

18

In 1864…heavy rains combined with melting snow to cause much flooding on north clear creek in Blackhawk.  Many bridges on the road to Denver were washed away by the high water on clear creek.

In 1893…northwest winds were sustained to 56 mph with an extreme velocity to 60 mph.

In 1960…large hail to 1 inch in diameter damaged roofs and cars in metro Denver.  Heavy snow and rain in the foothills caused rock and landslides…which blocked some highways. There was widespread minor damage from lightning. Hail as large as 1 1/8 inch in diameter was measured at Stapleton Airport where winds gusted to 44 mph.

In 1975…a tornado touched down briefly just south of Buckley Field in Aurora.  A few minutes later the same tornado touched down in open country 8 miles northeast of Stapleton International Airport.  No damage was reported.

In 1985…3/4 inch hail fell just southeast of Aurora.

In 1988…lightning started a fire at a home in the foothills west of Boulder…causing 50 thousand dollars in damage.

In 1995…strong thunderstorms rumbled across metro Denver dropping mainly pea to marble size hail.  However…hail stones as large as 1 1/4 inches in diameter fell in Wheat Ridge and downtown Denver.  Hail piled up to 2 inches deep in Wheat Ridge and northwest Denver.

In 1996…the Buffalo Creek Wildfire started and spread rapidly on strong southwest winds at 20 to 30 mph.  Dry weather conditions contributed to the spread of the fire… Which burned nearly 12 thousand acres and destroyed 12 structures including some houses.

In 2001…a 19-year-old man was struck and killed by lightning as he was walking along the shoulder of U.S. Highway 36 in Westminster.

In 2003…hail to 3/4 inch in diameter was measured at Denver International Airport.

In 2010…a small tornado touched down near Firestone but did no damage.

18-19

In 2011…a severe thunderstorm in central Adams County produced large hail and heavy rainfall on the 18th. Large hail from 1 inch to 1 3/4 inches in diameter…was reported in Commerce City…2 miles south-southeast of Federal Heights…Northglenn… And 2 miles south of Thornton. In Commerce City…the storm uprooted trees and knocked out power lines. A carport was lifted off the ground and struck the power lines overhead. Heavy rain…from 1.0 to 1.5 inches fell in less than 2 hours in Commerce City and near Brighton. The combination of hail and strong winds broke windows in Northglenn. In the foothills…moderate to heavy snow showers developed overnight. Storm totals included: 10.5 inches at gold hill…9.5 inches… 3 miles west of Jamestown; 9 inches at Lake Eldora; with 6 inches… 11 miles southwest of Gilpin and 4 miles east-northeast of Nederland. At Denver International Airport…total rainfall over the 2-day period totaled 1.71 inches. In addition…a peak wind gust to 37 mph was recorded on the 18th.

18-20

In 1915…3.9 inches of snow fell in the city.  The estimated amount of snow that melted as it fell was 6.2 inches which would have totaled an estimated 10.1 inches of snowfall. Precipitation totaled 1.03 inches.  North winds were sustained to 32 mph on the 18th.  Low temperatures dipped to 25 degrees on both the 18th and 20th…establishing record minimums for both dates.

In 1988…prolonged heavy rainfall drenched metro Denver. The event began when heavy thunderstorms on the 18th caused some street flooding and power outages…followed by steady rain on the 19th and 20th.  Rain amounts across metro Denver totaled 3 to 4 inches.  Rainfall totaled 3.71 inches at Stapleton International Airport where north winds gusted to 39 mph on the 20th.  Four to eight inches of snow fell in the foothills above 7 thousand feet.

18-26

In 2023…smoke and haze from massive wildfires in Canada
significantly impacted air quality and visibility across
Denver and the rest of northeast Colorado.

19

In 1927…southeast winds were sustained to 40 mph with gusts to 44 mph.

In 1956…a thunderstorm wind gust to 54 mph was recorded at Stapleton International Airport.

In 1969…hail stones to 1 inch in diameter were measured in Arvada and Aurora.  Some minor damage was reported. Pea to marble size hail fell in Westminster.

In 1972…a tornado was reported by aircraft about 5 to 10 miles east of Parker.

In 1988…lightning started a fire at a house in the Denver suburb of greenwood village…causing 2 thousand dollars in damage.

In 1991…strong thunderstorms over east metro Denver produced wind gusts of 56 to 60 mph.  The strong winds downed power lines…trees…and fences at some locations in Aurora. Thunderstorm outflow winds gusted to 60 mph at Stapleton International Airport.

In 1994…severe thunderstorms rumbled across metro Denver. The storms produced wind gusts averaging 65 mph and hail up to dime size.  Wind gusts to 77 mph were recorded in Brighton.  Numerous trees and power poles were downed by the winds.  One power pole fell onto spectators at a high school graduation ceremony in commerce city…injuring 6 people.  In fort lupton…trees fell onto 2 parked cars… Knocking out the windshields.  Hail to 3/4 inch in diameter was reported in Littleton.  A thunderstorm wind gust to 52 mph was recorded at Stapleton International Airport.

In 1995…a slow moving tornado…which was mainly discernible by its dust and debris cloud…was spotted 2 miles northeast of Denver International Airport or about 10 miles northwest of bennett.  No damage was reported.

In 2007…lightning struck a 33-ft statue of jesus at mother cabrini shrine…in the foothills west of Golden.  The blast broke off one of the statue’s arms and a hand…and also damaged a foot.  It cost an estimated $200…000 to repair.

In 2009…lightning struck the roof of a residence in Highlands Ranch. The home was not a total loss…but the fire caused extensive damage.

In 2010…a thunderstorm produced hail up to 7/8 inch in diameter in Thornton.

19-20

In 1864…a devastating major flash flood occurred on the normally dry and sandy Cherry Creek in Denver.  The flood was caused by heavy thunderstorm rainfall and hail over the palmer ridge to the south of the city in both the Cherry Creek and plum creek basins.  Nineteen deaths occurred along the South Platte River and Cherry Creek in Denver.  The torrent swept cattle and sheep along with large trees and houses before it washing out several bridges…and moving large structures from their foundations.  All city records were destroyed when city hall washed away.  The rocky mountain news building…built on stilts in the middle of the creek…was totally destroyed by the raging waters…which were as deep as 5 feet on the morning of the 20th.  Once the flood waters receded…much sand and gravel was left behind.  Property damage from the flood was estimated at nearly one million dollars.  This was the first major flood of record in the city.

20

In 1874…after a light late afternoon shower…3 rainbows were visible in the eastern sky.  The two upper bows were of the usual colors.  The lower bow had a deep violet center with a faint yellow and white rim.

In 1892…apparent post-frontal north winds were sustained to 40 mph with gusts to 48 mph.  A trace of snow was the last snowfall of the season.

In 1899…snow pellets from 1/4 to 3/8 inch in diameter fell from a thundershower during the late afternoon.  West winds were sustained to 42 mph with gusts as high as 48 mph.

In 1904…southeast winds were sustained to 40 mph with an extreme velocity of 42 mph produced by a thunderstorm.

In 1961…a tornado tore through central Douglas County…1 1/2 miles north of Castle Rock.  The storm struck 2 ranches and the property of a drilling company.  A car on the highway was lifted off the road and slammed into a truck…injuring the two occupants.

In 1983…heavy rain fell in Aurora with 1.00 to 1.50 inches of precipitation.  Local flooding occurred in Lakewood.

In 1990…1 inch diameter hail fell at Buckley Field in Aurora.  Minor damage was reported to autos…buildings and signs.

In 1995…hail as large as 3/4 inch in diameter fell near bennett where a funnel cloud was sighted.

In 2001…damaging winds developed behind a vigorous cold front that moved south from Wyoming into metro Denver. High winds…gusting to 58 mph at Denver International Airport…downed trees and power lines and kicked up blowing dust…dirt…and debris…reducing the visibility to near zero at times.  The poor visibility caused a multi-vehicle accident along U.S. Highway 85 north of Fort Lupton.  Six people were treated for minor injuries.  Several vehicles… Including semi-trailers…were blown off I-70 east of Denver. About 32 thousand Xcel Energy customers in metro Denver were without electricity for up to 2 hours.  At least a dozen incoming flights at Denver International Airport were diverted to other airports.  All departing flights were grounded for at least an hour.  At Southwest Plaza…shoppers were evacuated as rocks holding a tarp on a portion of a roof under repair toppled into the mall.  After the passage of the cold front…temperatures plunged from the lower 70’s to the mid 30’s in one hour as light snow developed.  Heavy snow developed in the foothills during the evening.  Peak wind reports included 68 mph near Parker and 63 mph near Sedalia.  Snowfall totals included:  7 inches near Blackhawk… At Ken Caryl ranch…and near Sedalia; 6 inches in Coal Creek Canyon…at Eldorado Springs…and atop Lookout Mountain; 5 inches at Chief Hosa…in Louisville…Rollinsville…and wheat ridge; and 4 inches in Aurora…Bailey…Parker…Castle Rock and near Morrison.  Low temperature of 31 degrees during the early morning of the 21st equaled the record low for the date last set in 1931.

In 2004…severe thunderstorms produced hail as large as 1.25 inches near Ft. Lupton and hail to 1.50 inches 10 miles north of Ft. Lupton.

In 2014…severe thunderstorm produced hail… From 1 to 1 1/4 inches in diameter…across parts of Aurora…Denver… Englewood and Lakewood.

20-21

In 1891…heavy rain was mixed with snow at times and totaled 2.02 inches in the city.  Snowfall was 1.0 inch.  Northeast winds gusted to 28 mph on the 20th.

20-22

In 1959…a three-day rain caused some flooding in metro Denver where rain totaled 1.68 inches at Stapleton Airport. Showers…accompanied by hail near Brighton…caused some damage to truck crops.  Heavy snow in the foothills caused damage to power and telephone lines.

20-27

In 2002…lightning sparked a wildfire near Deckers.  Extremely dry conditions and very strong winds the following day allowed the fire…known as the Schoonover…to consume 3850 acres before it could be contained.  Thirteen structures were destroyed…including 4 homes…resulting in 2.2 million dollars in damage.

21

In 1874…an extensive fire at central city in the mountains to the west of Denver produced large columns of smoke that were visible from the city.  In the afternoon…the smoke and fire produced a dark inky black convective cloud…which spread over the city and produced brief strong and gusty winds along with a few sprinkles of rain.

In 1880…west winds increased to a sustained velocity of 40 mph during the afternoon.

In 1893…north winds were sustained to 48 mph.

In 1914…a severe thunderstorm was attended by hail…excessive rainfall which totaled 1.94 inches…and an unusual amount of vivid lightning.  The heavy rainfall of 0.83 inch in 15 minutes produced flooding…which caused considerable damage to bottom lands in eastern and southern parts of the city. Many garden tracts and cellars were flooded.  Southwest winds were sustained to 29 mph with gusts to 34 mph.

In 1935…no precipitation occurred…making this one of only two days without precipitation during the entire month.  The other day was the 10th.  Precipitation totaled 4.95 inches for the month.

In 1952…a tornado produced a high column of dust and dirt over northwest Denver.  No damage was reported.

In 1988…a microburst wind gust to 52 mph was recorded at Stapleton International Airport.

In 2002…very strong winds occurred over metro Denver and northeastern Colorado as a developing surface low pressure center intensified.  Trees and branches snapped…downing power lines across parts of metro Denver.  About 20 thousand residents lost electricity.  The strong winds produced much blowing dust and dirt especially to the northeast of metro Denver.  Winds gusted to 61 mph at Parker.  South winds gusted to 58 mph at Denver International Airport.

In 2006…a large dust devil formed near quincy reservoir in south Aurora.  The tall column resembling a tornado or smoke plume extended upward into small high-based cumulus clouds and was visible for miles across southern Aurora and eastern centennial.  No damage was reported.

In 2014…severe thunderstorms occurred in and around metro Denver. The storms produced large hail…from quarter to golf ball size. Frontier Airlines canceled 16 flights…when several planes sustained hail damage. Forty flights at Denver International Airport were either delayed or canceled. Some homes in Green Valley Ranch…east of Denver… Were damaged by hail. Several vehicles were also damaged. Five short lived tornadoes touched down near Bennett and byers but no damage was reported. The storms also produced heavy rain and strong damaging winds. The wind downed trees and power lines east of Denver. The heavy rain and hail…up to 6 inches deep in spots…caused street flooding around the metro area. The hailstorm at dicks sporting goods park knocked out power to the stadium where the 4a and 5a girls soccer championship games were about to be played. The inclement weather snarled traffic on Interstate 70…Pena Boulevard… U.S. 85 and elsewhere due to the flooded roads. In some areas…snow plows were called out to clear the hail. Parts of Tower Road and Peoria Street…and other roads in Commerce City… Were closed through the late evening hours…because of standing water. Several vehicles stalled in standing water where water pooled in the underpasses. At Denver International Airport…1.2 inches of water was observed…along with a wind gust to 42 mph from the northwest.

21-22

In 1878…overnight heavy rains of cloudburst intensity on the palmer divide to the south of the city caused flash flooding on Cherry Creek in Denver…which resulted in 2 deaths.  A wall of water swept through the city between 2:00 am and 3:00 am on the morning of the 22nd.  The flood was so sudden and unexpected that homes along the creek in the city were submerged in water knee deep before the slumbering occupants knew anything about it.  By daybreak the banks on both sides of the creek were lined by residents viewing the destruction caused by the raging waters in such a short time.  Seven bridges across the creek were destroyed in the city.  Damage to private and city property was estimated between 30 and 50 thousand dollars.  Quite a number of cattle and sheep were killed along the reach of the creek.  Only 0.01 inch of rain fell in the city on the 21st with a trace of rain on the 22nd.  Flash flooding also occurred on Kiowa Creek near Bennett on the night of the 21st when the flood waters washed out the Kansas Pacific Railroad bridge.  An east bound freight train plunged into the turbulent waters killing the three crewmen.  The locomotive was completely buried in the sand and never found to this day!
21-23

In 1876…snow changed to heavy rain over the city…resulting in widespread flooding along Cherry Creek and the South Platte River…nearly as great as the flash flood of May 19-20…1864.  However…damage was greater because the city had grown much larger and there were more bridges for the flood waters to destroy.  Precipitation in the city totaled 6.70 inches from 10:00 pm on the 21st through 3:00 am on the 23rd.  The greatest precipitation ever recorded in Denver in 24 hours…6.53 inches…occurred on the 21st and 22nd.  Small buildings and bridges along Cherry Creek were washed away by the flood waters.  Bridges over the South Platte River were damaged.  The city irrigation ditch was damaged and rendered unfit for service.  Strong winds at speeds of 30 to 40 mph drove the heavy rain through brick walls 12 to 16 inches thick.  Many sheep and cattle were either killed by lightning or drowned…including some 100 head of cattle in Jefferson County alone.  There was immense damage to railroad tracks…especially the Kansas Pacific Line to the east of the city.  The Colorado central suffered estimated damage of 10 to 15 thousand dollars.  In addition…the heavy rain caused extensive flooding on soda and bear creeks in the foothills.  Flooding along Boulder creek inundated farm and pasture land in the Boulder valley and damaged a few bridges.  Rail travel had to be suspended in the area for several days.

22

In 1876…the most precipitation in Denver on any calendar day…6.50 inches…occurred.

In 1901…northeast winds were sustained to 41 mph with gusts to 45 mph.

In 1903…west winds were sustained to 45 mph with gusts to 55 mph from an apparent microburst…which produced a trace of rain.

In 1976…the public reported 3/4 inch diameter hail and wind gusts to 53 mph near Littleton.

In 1987…golf ball size hail fell in the Lorretto Heights area of south metro Denver.

In 1991…a tornado touched down briefly in Castle Rock.  No injuries were reported.

In 1993…an off duty national weather service employee reported hail up to golf ball size just west of the city of Denver in Jefferson County.  Thunderstorm wind gusts reached 58 mph at Jefferson County airport near Broomfield and 33 mph at Stapleton International Airport.

In 1996…a severe thunderstorm pummeled northwest and northern sections of metro Denver with large hail ranging in size from 3/4 to 2 inches in diameter.  The cities of Arvada and Westminster were the hardest hit.  The insurance industry estimated 60 million dollars in damage to homes and personal property and 62 million dollars in damage to automobiles…for a total of 122 million dollars in insured losses.  This estimate also included the cities of Golden… Thornton…and Wheat Ridge.  This was the fourth worst hailstorm to hit metro Denver in the last 10 years.

In 1998…large hail fell across north metro Denver.  Hail as large as 1 1/2 inches in diameter was measured in Broomfield and Hudson.  Hail to 1 1/4 inches fell in Roggen.  Hail to 1 inch fell in Brighton…near Keenesburg… In Watkins…and in the city of Denver.  Lightning ignited a house fire in Ft. Lupton.  A warehouse worker in Denver was injured when he was knocked off a loading dock by a lightning bolt.  The bolt skipped off a nearby radio tower and struck him in the arm.  He was treated for numbness in his right arm and released.

In 1999…severe thunderstorms produced 7/8 inch diameter hail over the city of Denver…with one inch diameter hail reported in Aurora…and 3/4 inch hail near Watkins.

In 2006…a lightning strike sparked a fire and damaged the roof of a recreation center in evergreen.  The fire spread into some brush and consumed about one quarter acre before it was extinguished.  Severe thunderstorms produced strong wind gusts across portions of metro Denver.  Winds gusted to 72 mph in Georgetown…62 mph near Parker and Bennett… 60 mph in Castle Rock…and 59 mph in Longmont.  The winds caused no reportable damage.  A thunderstorm produced southwest wind gusts to 52 mph at Denver International Airport.

In 2008…an EF1 tornado touched down near Dacono.  The tornado overturned a five-wheel trailer and injured a man sitting inside.  It also destroyed 5 outbuildings. In addition…large hail up to 1 1/2 inches in diameter… Was reported in the vicinities of Golden and Longmont.

In 2014…a severe thunderstorm Denver area produced nickel to quarter size hail in parts of west Denver and near Bennett. Locally heavy rainfall produced some minor street flooding in parts of metro Denver. The heavy rainfall produced localized flash flooding near Bennett. Rainfall totaled 0.54 inches at Denver International Airport.

22-23

In 1933…high winds and gales overnight caused considerable damage in and near the city.  Much greenhouse glass was broken…which caused damage to sheltered plants.  Great numbers of plants growing in the open were damaged or killed by wind-driven sand and soil.  Fields were eroded by the wind and a few trees were uprooted.  West winds were sustained to 38 mph with gusts as high as 65 mph in downtown Denver on the 22nd.

23

In 1916…southeast winds were sustained to 43 mph with gusts as high as 52 mph.  The winds were strong for several hours during the afternoon.

In 1965…thunderstorm outflow wind gusts to 59 mph were recorded at Stapleton International Airport.

In 1987…slow moving thunderstorms bombarded metro Denver. One inch diameter hail was reported in south central Denver.  Torrential rain caused widespread street flooding… Stalling traffic throughout the area.  Rainfall totaled 2.10 inches in just 25 minutes in extreme southeast Aurora. Many other locations in Aurora and east Denver reported 1 to 1 1/2 inches of rain in about 30 minutes.  Thunderstorm rainfall totaled 1.33 inches at Stapleton International Airport where 1/4 inch diameter hail was measured and north winds gusted to 40 mph.  A man was slightly injured by lightning near Stapleton International Airport.  Lightning also started a fire that severely damaged a house in Aurora.

In 1990…a microburst wind gust to 52 mph at Stapleton International Airport produced some blowing dust.

In 1991…thunderstorms moving from southwestern sections of metro Denver to the east of Denver produced large hail up to golf ball size.  An estimated 5 thousand homes and 8 thousand cars received considerable damage.  Early estimates placed damage costs around 60 million dollars. Three funnel clouds were also reported…two by personnel at Buckley Field and the other by a storm spotter.  Heavy rain produced street flooding in Aurora where hail accumulated to a depth of 6 inches.  As the storms moved to the east…golf ball size hail was reported at Strasburg.

In 1997…hail to 3/4 inch diameter fell in Broomfield.

In 2002…a very strong microburst near Strasburg swept a woman into a swirl of dirt and carried her about 150 feet. The woman was in an open field…corralling a yearling horse… When the incident occurred.  Fortunately…she received only minor injuries.

23-24

In 2002…a pacific storm system brought much needed snow to the mountains and foothills with a mix of rain and snow on the plains.  The most snow fell from central Jefferson County northward.  Snow totals included:  13 inches in Coal Creek Canyon…11 inches near evergreen and atop gold hill… 10 inches near Blackhawk and Conifer and atop Crow Hill… 9 inches near Rollinsville…and 8 inches near Genesee and Golden.  Rain was mixed with snow across the city. Precipitation totaled 0.61 inch at Denver International Airport.  Snowfall was less than an inch at the site of the former Stapleton International Airport.  The storm brought unseasonably cold air to metro Denver.  Three temperature records were set.  Low temperature of 31 degrees on the 23rd was a record minimum for the date…as was the low of 32 degrees on the 24th.  The high temperature of only 48 degrees equaled the record low maximum for the date.

As we move further into spring we begin to less winter-like weather and more spring weather.  In looking at Denver weather history we can see that transition with more mentions of severe rains, flooding, tornadoes and other spring and summer-like severe weather.

From the National Weather Service:

8-10

In 1979…4.3 inches of snow fell at Stapleton International Airport where northwest winds gusted to 30 mph on the 8th. Most of the snowfall…2.3 inches…occurred on the 9th. High temperature of only 35 degrees on the 9th equaled the record low maximum for the date.

9-10

In 1889…heavy rainfall totaled 2.15 inches in downtown Denver.  The cold rain was mixed with snow at times overnight.  Temperatures on the 10th ranged from a high of 38 degrees to a low of 32 degrees with north winds sustained to 22 mph.

In 2003…a late spring snowstorm hammered the mountains… Eastern foothills…and urban corridor.  The heaviest snowfall occurred north of interstate 70.  The heavy wet snow caused damage to trees throughout metro Denver and downed power lines.  About 40 thousand people along the urban corridor were without power.  Storm total snowfall amounts included:  11.5 inches in Louisville… 8 inches in Boulder and Broomfield; 7 inches in Thornton…Broomfield…at Denver International Airport… And at the site of the former Stapleton International Airport; and 6 inches 4 miles east of Denver.  Snowfall ranged from 4 to 9 inches across extreme southern weld County.  In the foothills…15 inches of snow fell near Jamestown…9 inches at Rollinsville and Rawah…with 8 inches at Chief Hosa and atop Lookout Mountain. The snow was accompanied by thunder on the afternoon of the 9th at Denver International Airport where west winds gusted to 25 mph on the 9th and north winds gusted to 22 mph on the 10th.

In 2015…from the 9th to the 10th…a strong storm system brought heavy snow to areas in and around Denver. Moderate to heavy rain showers transitioned over to snow by early in the evening on the 9th. Heavy wet snow overnight caused many trees to break under the pressure of the sudden weight. Tree damage ranged from minor to significant…with old growth trees losing large limbs and new trees sustaining fatal damage. Power outages affected about 43350 Xcel Energy customers in metro Denver. The Intermountain Rural Electric Association also reported about 1000 power outages in the Strasburg areas. In the high country…CDOT shut down Interstate 70 between the Eisenhower Tunnel and Silverthorne due to multiple crashes.

10

In 1875…a windstorm sand-blasted the city from 10:00 am until midnight.  Northwest winds sustained to 60 mph brought clouds of sand…which caused high damage to unfinished buildings.

In 1912…a vigorous cold front produced strong north winds and rain.  North winds were sustained to 48 mph with gusts as high as 60 mph.  Rainfall totaled 1.10 inch.

In 1935…no precipitation occurred…making this one of only two days without precipitation during the entire month.  The other day was the 21st.  Precipitation totaled 4.95 inches for the month.

In 1956…northwest winds gusted to 53 mph at Stapleton Airport where the visibility was briefly reduced to 1/2 mile in blowing dust.

In 1974…strong winds caused 30 thousand dollars in damage to a building under construction in Lakewood.  Microburst winds gusted to 46 mph at Stapleton International Airport.

In 1988…lightning struck a house in Boulder…setting it afire.  The house…valued at 170 thousand dollars…was a total loss.

In 1989…golf ball size hail fell over southeast Denver near the junction of I-25 and I-225.  Hail to 3/4 inch in diameter fell over southeast Aurora.  Only 3/8 inch hail fell at Stapleton International Airport.

In 1991…high winds up to 63 mph raked the eastern foothills. Winds estimated to 50 mph tore a roof from a home in Lafayette.  A tower at Jefferson County stadium in west metro Denver was blown over by the high winds.  No injuries were reported.  Southeast winds gusting to 48 mph at Stapleton International Airport produced some blowing dust.  The temperature climbed to a high of 86 degrees… Equaling the record maximum for the date.

In 2005…severe thunderstorms produced hail as large as 2 inches in diameter in and near Longmont.

In 2023…severe thunderstorms produced large hail across to the eastern and southern portions of the Denver metropolitan area. The hail ranged in size from 1 to 1 3/4 inches in diameter. One storm developed over south Denver… while the rest formed along a line the stretched from Buckley AFB to between Lone Tree and Parker.

10-11

In 1918…post-frontal snowfall totaled 4.7 inches in downtown Denver.  Northwest winds gusted to 19 mph on the 10th.

In 1923…winds were strong and gusty on both days.  Northwest winds were sustained to 40 mph with gusts to 44 mph on the 10th.  North winds were sustained to 39 mph with gusts to 46 mph behind an apparent cold front on the 11th.

10-12

In 2011…a spring snowstorm brought heavy snow to the Front Range foothills and palmer divide. Storm totals included: 18 inches…4 miles south-southeast of Pinecliffe; 16 inches in Coal Creek Canyon; 15 inches…4 miles west-southwest of Eldorado Springs; 13 inches at Gold Hill…12 inches… 4 miles west-southwest of Conifer and 4 miles northwest of Elizabeth; 11.5 inches…6 miles southwest of Evergreen and 4 miles east-northeast of Nederland; 11 inches…3 miles east of Jamestown and 10.5 inches…3 miles east of Franktown and 3 miles south of Golden and 10 inches…10 miles north of Elizabeth. At Denver International Airport… 1 inch of snowfall was observed.

In 2023…a slow moving storm system produced a period of moderate to heavy rainfall across the urban corridor…Palmer Divide and adjacent plains. A 24-hr daily record of 2.92 inches occurred at Denver International Airport on the 11th…with a 2-day total of 3.75 inches on the 11-12th…and 3-day total of 4.40 inches from the 10-12th. The prolonged period of rainfall resulted in flooding…flash flooding and washed out roadways… including Cherry Creek State Park and the National Wildlife Refuge at the Rocky Mountain Arsenal. Three-day rainfall amounts south and southeast of Denver ranged from 4.00 to 7.00 inches. In the Front Range west of Denver…above 10 thousand feet…heavy wet snowfall ranged from 1 to 2 feet. The 3-day event propelled Denver into 4th place for rainfall in month of May…with a total of 5.53 inches.

11

In 1879…an apparent cold front during the afternoon produced sustained north winds as high as 60 mph and great clouds of blowing dust.  The dust filled the air until the thunderstorm rain began…which produced 1.46 inches of rainfall.  The rain ended during the evening.

In 1900…southwest winds were sustained to 40 mph with gusts to 46 mph.

In 1958…a microburst caused a brief wind gust to 55 mph at Stapleton Airport.

In 1963…south-southwest winds gusted to 48 mph at Stapleton Airport.  Winds May have been stronger over west Denver where some buildings were damaged.

In 1998…large hail fell over south metro Denver.  Hail as large as 1 1/4 inches in diameter was measured in Parker with 1 inch hail recorded in Littleton and 4 miles south of Lakewood in Jefferson County.  Hail to 3/4 inch diameter was measured in Douglas County…11 miles west- northwest of Parker.

11-12

In 2014…a strong storm system moved from southwest Colorado and produced heavy snow in and near the Front Range foothills and metro Denver. The snow was heaviest in the foothills where up to 2 1/2 feet of snow was observed. In the foothills… Storm totals included: 30 inches near Pinecliffe; 29 inches… 8 miles northeast of Four Corners; 28 inches near Pingree Park; 27 inches near Allenspark; 20.5 inches near Idaho Springs; 19.5 inches at Gold Hill; 19 inches near Genesee; 18 inches near Blackhawk; 17 inches at Aspen Springs; 16.5 inches near Ward; 13.5 inches at bergen park; with 11 inches at Evergreen. Along the urban corridor and Palmer Divide…storm totals included: 10.5 inches at Eldorado Springs; 10 inches at Ken Caryl; 9 inches at Superior; 8 inches near Morrison; 7.5 inches in Broomfield and Highlands Ranch; 7 inches in Denver… Near Franktown…Golden… Lakewood and Highlands Ranch; 6 inches…5 miles northeast of Westminster… 7 miles south of Lyons and near Parker; with 5.5 inches at Aurora. At Denver International Airport…1.1 inches of snowfall was observed… Along with 0.9 inches of water.

In 2023…a slow moving storm system produced a period of moderate to heavy rainfall across the urban corridor…Palmer Divide and adjacent plains. A 24-hr daily record of 2.92 inches occurred at Denver International Airport on the 11th…with a 2-day total of 3.75 inches on the 11-12th. The prolonged period of rainfall resulted in flooding…flash flooding and washed out roadways; including Cherry Creek State Park and the National Wildlife Refuge at the Rocky Mountain Arsenal.

12

In 1875…two forest fires on the eastern slope of the foothills were visible from the city.

In 1904…north winds were sustained to 40 mph with gusts to 48 mph.

In 1950…brilliant and complete primary and secondary rainbows arching across the sky were observed from Stapleton Airport.

In 1951…a wind gust to 51 mph was recorded at Stapleton Airport.

In 1984…winds gusted to 69 mph in Boulder.  Northwest winds gusted to 47 mph at Stapleton International Airport.

In 1987…a small weak tornado touched down for about 2 minutes in southeast Denver.  The twister hit a car dealership…blowing about a dozen windows out of cars and shattering four skylights on the building.  Some tin roofing was blown off a patio a block and a half away.  The tornado also downed a power pole.  Damage at the dealership was estimated at 10 thousand dollars.  A man was slightly injured by lightning in northwest Aurora.

In 1995…several funnel clouds were sighted near Parker. One of the funnels produced a short-lived debris cloud on the ground in an open field.  No damage was reported.

In 2015…a man suffered minor injuries when the tree he took shelter under was struck by lightning. He was jogging at City Park Golf Course when the incident occurred. The jogger was taken to the hospital for observation.

12-13

In 1907…the temperature warmed to a high of 73 degrees on the 12th…before a cold front produced a thunderstorm… Northeast winds sustained to 40 mph…and rain changing to light snow overnight.  Snowfall totaled only 2 inches…but the high temperature on the 13th was only 39 degrees.

In 1961…a storm that covered metro Denver with rain and snow started as thunderstorms on the evening of the 12th.  Hail to 1 1/2 inches in diameter was reported 10 miles northwest of Stapleton Airport.  Rain continued overnight and changed to snow on the 13th.  Snowfall totaled 6.4 inches and precipitation (rain and melted snow) 1.96 inches at Stapleton Airport where north winds gusted to 39 mph.  The rain and heavy wet snow caused icing damage to utility lines.  Heavy snow occurred in the foothills.

In 1982…a major storm dumped 1.50 to 3.50 inches of rain across northeast Colorado and deposited prodigious amounts of snow in the foothills.  Coal Creek Canyon southwest of Boulder was buried under 46 inches of snow with 39 inches at Nederland.  The heavy wet snow downed many powerlines in the foothills.  In Thornton…the roof of a school was damaged by water from the heavy rain.  At Stapleton International Airport…1.49 inches of rain were measured over the two day period.  The heavy rain ended a severe and prolonged drought.

In 2004…a winter storm produced heavy snow in excess of a foot in the foothills above 6 thousand feet while heavy rain fell across the city.  The heaviest snow occurred in the high country of Boulder County.  Storm total snowfall was 14.5 inches near Jamestown.  Rainfall totaled 0.81 inch at Denver International Airport with 0.94 inch recorded at Denver Stapleton.  A trace of snow was recorded at both locations.  East winds gusted to 24 mph at Denver International Airport on the 12th.

13

In 1905…a thunderstorm produced hail during the late afternoon.  Precipitation totaled 0.57 inch.

13-14

In 1912…heavy snowfall totaled 12.4 inches over the city. Most of the snow…9.9 inches…fell on the 13th…which was the greatest 24 hour snowfall in May at the time.  This was the last snowfall of the season.  The low temperature dipped to 27 degrees on the morning of the 14th.

In 1989…a spring storm brought heavy rain and snow to the foothills.  Metro Denver was soaked with 1 to 2 inches of rain.  Rainfall totaled 1.26 inches at Stapleton International Airport.  In the foothills…Echo Lake received 20 inches of snow.  A 30-ton Boulder slid onto I-70 east of the Eisenhower Tunnel…closing the freeway for 2 hours.

14

In 1910…a thunderstorm produced strong winds during the afternoon.  Northwest winds were sustained to 42 mph.

In 1913…light moist snow and light hail fell during short intervals…although no thunder was heard.  The trace of snowfall was the only snow of the month.  Precipitation… Mostly rain…totaled 0.44 inch.

In 1984…a pilot reported a tornado 16 miles east of Stapleton International Airport.  No damage was reported. A thunderstorm produced a 58 mph wind gust in Brighton. Thunderstorm winds gusted to 48 mph at Stapleton International Airport.

In 1989…lightning struck a home in evergreen…setting it afire.

In 1992…strong thunderstorm winds of unknown velocity… Knocked over and damaged the infield tote board at Arapahoe Park Racetrack just southeast of Aurora. Damage was estimated at 200 thousand dollars.  No injuries were reported.  Lightning started two house fires…causing 35 hundred dollars in damage in Adams County just 9 miles north-northwest of Denver.

In 1994…a sudden wind gust…estimated at 40 mph…blew a portion of the roof off a shopping center in Lafayette. The roof also damaged two parked cars in an adjacent lot.

In 2001…a construction worker in Castle Rock received minor injuries when lightning struck close-by.

In 2002…a microburst wind gust to 53 mph was recorded at Denver International Airport.

In 2007…severe thunderstorms producing large hail…very heavy rain…and tornadoes impacted the urban corridor and adjacent plains.  Heavy rain associated with a severe thunderstorm caused flooding along a small tributary draining into the South Platte River.  The incident took place at 13th and Decatur St….near Invesco Field.  The floodwaters inundated the bike trail adjacent to the creek. A woman with her child sought refuge under a bridge and became trapped by the high water.  The woman slipped and the stroller containing the child was swept into the swift current.  The child drowned.  Rainfall totaled 0.42 inches at Denver International Airport.  Elsewhere…golfball hail was reported near Hudson.  Hail…up to one inch in diameter…was observed in Boulder and Lyons. Thunderstorm wind gusts estimated to 70 mph were reported near Buckley Air Force Base…with a peak wind gust to 37 mph observed at Denver International Airport.  A small tornado touched down near Ft. Lupton but did no damage.

14-15

In 1977…high winds up to 100 mph felled hundreds of trees in Gilpin County and caused extensive damage to telephone and power lines.  Lumber and steel tanks were blown around in Boulder canyon.  West winds gusted to 46 mph at Stapleton International Airport on the 15th.

14-18

In 1996…a period of unusually warm weather resulted in 4 record maximum temperatures in 5 days.  The record high temperatures were 87 degrees on the 14th…89 degrees on the 15th…and 93 degrees on both the 16th and 18th.  The temperature climbed to only 81 degrees on the 17th which was not a record.

15

In 1894…southwest winds were sustained to 38 mph with gusts to 50 mph.

In 1910…an apparent cold front produced sustained northeast winds to 48 mph.

In 1986…a thunderstorm dumped an inch of rain in an hour over the eastern part of Aurora.  Total rainfall from the storm was 1.62 inches.

In 1989…a 47 year old man…a Lakewood police officer…was struck and injured by lightning.  Small hail piled up 3 to 4 inches deep near Golden.  There was reported street flooding from heavy thunderstorm rains over western metro Denver.  Rainfall totaled 0.76 inch at Stapleton International Airport.

In 1990…a thunderstorm produced a wind gust to 69 mph at Jefferson County airport in Broomfield.  Thunderstorm winds gusting to 49 mph at Stapleton International Airport produced some blowing dust.

In 1991…a funnel cloud was sighted near Morrison.  Later… Hail up to 2 inches deep covered U.S. Highway 285 at South Turkey Creek Road in west metro Denver.  Baseball size hail was reported on the east side of Littleton.  Dime size hail was reported in Boulder.

In 1993…lightning started a fire which damaged a home in Boulder.  No one was injured.

In 1997…a wind gust to 58 mph was recorded at the site of the former Stapleton International Airport.  A street sign was blown down at the Havana Street exit along I-70.

In 1999…lightning ignited a small fire in a 3-story structure in sunshine canyon above Boulder.  The fire was quickly extinguished and caused only minor damage.

In 2003…thunderstorms produced very heavy rainfall and localized flash flooding in the foothills of central Boulder County.  Rainfall ranged from 1.5 to 2.5 inches in less than 2 hours.  Water ranging in depth from 6 to 9 inches covered state highway 119 in Boulder canyon.  Dirt and rocks also washed over the roadway.  Some basements were flooded in the sugarloaf area.  Rockslides were also reported at Boulder falls…Lefthand Canyon…and Fourmile Canyon.

In 2015…Severe thunderstorms produced hail…from nickel to half dollar size…across parts of Adams…Arapahoe…Douglas and Weld Counties. Two tornadoes touched down briefly in Adams County; one tornado…rated an EF1…destroyed a storage shed north of Strasburg.

15-16

In 1957…heavy snowfall totaled 8.8 inches at Stapleton Airport. The greatest amount on the ground was 3 inches.

In 1986…a spring storm dumped 1 to 2 inches of rain over metro Denver…but 2.71 inches fell at Buckley Field in Aurora.  Rainfall only totaled 0.84 inch at Stapleton International Airport.  Snow fell in the foothills with 7 inches recorded in coal creek canyon southwest of Boulder.

In 2016…1.22 inches of precipitation was measured at Denver International Airport which was the greatest daily amount for the month.

In 2020…a potent storm system dropped out of the northern Rockies and produced moderate to heavy snow over portions of the Front Range mountains…foothills and adjacent plains. The heaviest snow fell in and near the foothills north of I-70. In the mountains and foothills…storm totals included: 30 inches near Jamestown…27 inches near Nederland…22 inches near Allenspark…21 inches near St Mary`s Glacier…18 inches in Estes Park…16 inches near Crescent Village and Deer Ridge…15.5 inches near Aspen Springs…and 15 inches near Pinecliffe. In Boulder…16.9 inches of snow helped to establish a new seasonal snowfall record of 151.2 inches. The previous seasonal snowfall record in Boulder was 142.9 inches in 1908-1909. Along the I-25 corridor…storm totals included: 14.5 inches in Niwot…13.5 inches in Frederick…13 inches in Broomfield… 12 inches in Lafayette and near Longmont…10.5 inches in Arvada…10 inches in Erie…Louisville…and Westminster…7 inches in Brighton…6.5 inches in Edgewater and Northglenn…and 5.5 inches in Greeley. Snowfall totaled 1.9 inches at Denver International Airport.

In 2021…a storm system produced bands of heavy snow in and near the Front Range Foothills. Storm totals included: 13.8 inches at St. Mary`s Glacier…12.9 inches at Aspen Park…10 inches in Genesee…9.5 inches at Ken Caryl…9 inches in Crescent Village…8.5 inches in Arvada and Westminster…8 inches at Evergreen and Sedalia…with 3 to 7 inches elsewhere. At Denver International Airport… 5.7 inches inches of snowfall was observed.

16

In 1875…a heavy hail storm turned into heavy rain during the afternoon.  Rainfall totaled 0.86 inch in just 37 minutes…while the temperature dropped 22 degrees in 22 minutes.  Precipitation totaled 0.90 inch.

In 1894…west winds were sustained to 48 mph with gusts to 56 mph.

In 1949…a tornado was observed for 16 minutes…20 miles to the southeast of Stapleton Airport.  The tornado moved 5 miles to the northeast before dissipating.  No damage was reported.

In 1963…intense lightning started several forest fires in the foothills southwest of Denver near Deckers and Cheeseman Lake.  Little precipitation fell from the storms to alleviate the unusual dry conditions so early in the season.

In 1978…thunderstorm winds caused damage in southeast Aurora.  Winds of 60 to 80 mph blew down numerous fences and damaged several homes under construction.  High winds tore docks loose at Cheery Creek Reservoir…sinking 3 or 4 boats and damaging about 15 others.  At Stapleton International Airport where winds gusted to 60 mph…a 727 jet suffered 15 hundred dollars damage when wind toppled a runway light onto it.  The public reported an unconfirmed tornado 7 miles south-southwest of Stapleton International Airport.

In 1990…a line of thunderstorms moving across metro Denver uprooted a large ash tree…which fell and blocked the outside doors to a Denver elementary school…briefly trapping the students inside.  Thunderstorm wind gusts to 69 mph were reported at Jefferson County airport. Northwest winds gusted to 44 mph at Stapleton International Airport.

In 1991…two tornadoes touched down briefly in Castle Rock… But no injuries or damage were recorded.  Heavy thunderstorm rains of 0.50 to 1.10 inches in a couple of hours caused Lena Gulch near Golden to flood.  No damage was reported.

In 1996…dry microburst winds of unknown strength overturned a trailer and damaged storage sheds in Strasburg east of Denver.

16-17

In 1981…a heavy rain storm dumped 1 to 2 1/2 inches of rain across metro Denver.  Rainfall totaled 1.27 inches at Stapleton International Airport where north winds gusted to 38 mph on 17th.

In 1983…a very strong late spring storm dumped heavy snow over the Front Range.  Strong winds with the storm produced blizzard conditions at times.  Sustained winds were 20 to 40 mph with a peak gust to 55 mph at Stapleton International Airport.  The foothills received 1 to 2 feet of snow with 4 to 12 inches along the foothills.  Howling winds whipped the snow into drifts several feet deep…closing schools and highways.  Stapleton International Airport was forced to reduce flight operations…closing 2 of 4 runways and stranding hundreds of travelers.  Most of the damage and inconvenience caused by the storm was in power outages… Which occurred when wind and heavy wet snow caused hundreds of power poles to snap and topple.  About 20 square miles of Denver were blacked out.  Precipitation from the storm totaled 1 to 3 inches.  At Stapleton International Airport… Snowfall totaled 7.1 inches with a maximum snow depth on the ground of only 2 inches due to melting.  The high temperature of 40 degrees on the 17th was a record low maximum for the date.  Due to the heavy moisture content of the storm…widespread street flooding occurred on the 18th when much of the snow melted under the warm May sun and temperatures climbed to a high of 57 degrees.

In 1995…significant moisture and upslope flow caused flooding across metro Denver.  Moderate to heavy rains… Which began on the evening of the 16th…developed in the foothills and spread eastward over metro Denver throughout the night.  The heavy rains brought many creeks and small streams to bankfull or slightly over.  Locations along the foothills received between 3 and 4 inches of rainfall from the storm.  Boulder received 3.60 inches of rainfall for the 24-hour period…causing minor street flooding near small streams.  To the northwest of Boulder…a bridge which crossed Fourmile Creek was washed out.  Numerous rock and mudslides occurred in foothills canyons…closing portions of U.S. Highways 6 and 40 and state highway 119 for a few hours at a time.  Rocks were piled 6 feet deep on a stretch of state highway 119 along with Boulders as large as cars on U.S. Highway 6.  A parking lot near a creek in Golden caved in leaving a hole the size of an 18-wheeler.  Rushing water washed out a 50-foot stretch of a road in Westminster. Rainfall totaled 1.75 inches at Denver International Airport…but only 1.42 inches at the site of the former Stapleton International Airport.

A very eventful week in Denver weather history. Four tornadoes are mentioned and many reminders that winter may not be over just quite yet.

From the National Weather Service:

1-5

In 1898…snowfall totaled 15.5 inches in downtown Denver. Most of the snow…6.2 inches… Fell on the 3rd. Most of the snow melted as it fell. The greatest snow depth on the ground was only 2.5 inches on the 3rd at 8:00 pm. This was the only snowfall during the month. Northeast winds were sustained to 22 mph on the 1st.

2-3

In 1979…heavy rain changed to snow on the 2nd. Snowfall totaled 3.9 inches at Stapleton International Airport… Where northwest winds gusted to 26 mph. The greatest depth of snow on the ground was only 1 inch at midday on the 2nd due to melting. Total precipitation for the 2 days was 1.65 inches.

2-4

In 1987…a slow moving storm brought rain…wind… And snow to metro Denver. Rainfall totaled 1.04 inches at Stapleton International Airport where north winds gusted to 48 mph on the 3rd. The foothills received 5 to 10 inches of snow.

2-5

In 2001…a very slow moving pacific storm system became parked near the Four Corners region…which allowed heavy snow to develop above 6500 feet in the foothills with a mix of rain and snow over lower elevations of metro Denver. Snowfall totals included: 21 inches atop Crow Hill and at Idaho Springs; 19 inches near Blackhawk; and 18 inches in Coal Creek Canyon…Genesee… And 11 miles southwest of Morrison. Snowfall totaled 6.2 inches at the site of the former Stapleton International Airport. Precipitation (rain and melted snow) totaled 2.09 inches at Denver International Airport where north winds gusted to 30 mph on the 2nd.

3

In 1898…heavy snowfall of 6.2 inches fell over downtown Denver. Most of the snow melted as it fell. The greatest snow depth on the ground was 2.5 inches during the evening.

In 1907…the all-time lowest recorded temperature in the month of May…19 degrees… Occurred.

In 1925…an apparent microburst produced sustained northeast winds to 44 mph with gusts to 52 mph. Rainfall was only 0.01 inch in downtown Denver.

In 1981…lightning struck 9 golfers at the south suburban golf course. None were injured seriously.

In 1983…hail 1 1/2 inches in diameter fell at Green Mountain west of Lakewood…with 3/4 inch stones reported in Lakewood.

In 1986…a thunderstorm wind gust to 51 mph was recorded at Stapleton International Airport.

3-5

In 1908…rain changed to snow on the evening of the 3rd and continued through the early evening of the 5th. Snowfall totaled 10.0 inches over downtown Denver. This was the last measurable snow of the season. Precipitation totaled 1.51 inches. North winds were sustained to 23 mph on the 3rd…33 mph on the 4th… And 21 mph on the 5th. Three temperature records were set. High temperatures of 30 degrees on the 4th and 38 degrees on the 5th were record low maximum temperatures for the dates. The reading on the 4th was also the all-time record low maximum for the month of May.

In 2007…a slow moving pacific storm system… From the desert southwest…brought a period of unsettled weather to the region. During the 3-day period…locally heavy snow was reported over parts of the Front Range foothills. Storm totals included: 15 inches near Conifer…14.5 inches west of Jamestown…13.5 inches; 6 miles southwest of Evergreen…and 12.5 inches at pine junction. Severe thunderstorms…producing large hail… Up to one inch in diameter were observed in the vicinity of Boulder and Hudson. Lightning struck a residence in Jefferson County. The roof was hit…causing the attic to catch fire. At Denver International Airport…lightning struck a united airlines jet as it was pushing away from the gate. The passengers were taken off the jet and put on another plane.

4

In 1893…northwest winds were sustained to 42 mph.

In 1971…a funnel cloud was sighted 10 miles southwest of Boulder. Hail stones to 1 inch in diameter fell in southeast Denver…but caused only minor damage.

In 2006…a severe thunderstorm produced hail to 1.00 inch in diameter in Aurora near Cheery Creek Reservoir.

In 2010…high winds downed trees and power lines across parts of the Front Range foothills and urban corridor. Downed power lines sparked a 12-acre wildfire near Conifer. In Boulder…Longmont and Louisville… The wind damaged roofs and broke windows and skylights. Peak wind gusts included: 75 mph in northwest Longmont…71 mph at the national wind technology center and 4 miles south- southwest of superior…61 mph at Broomfield and 56 mph in Erie. At Denver International Airport…a peak wind gust to 46 mph was observed.

4-5

In 1986…high winds buffeted the foothills. Wind speeds of 60 to 75 mph were recorded in Boulder. At Stapleton International Airport…west winds gusted to 45 mph on the 4th and to 40 mph on the 5th.

In 2000…a brief warm spell resulted in setting two daily high temperature records. The temperature climbed to highs of 87 degrees on the 4th and 89 degrees on the 5th.

4-8

In 1969…heavy rains caused flooding on Boulder Creek in Boulder…which resulted in one death on the 7th. Flooding also occurred on bear creek in Sheridan and on the South Platte River in Denver. Rain over most of the eastern foothills started late on the 4th and continued with only brief interruptions in many areas until the morning of the 8th. Very high rates of rainfall occurred on the 6th and 7th with the greatest intensities in a band along the foothills from about 25 miles southwest of Denver northward to Estes Park. Storm totals by both official and unofficial measurements exceeded 10 inches over much of this area and were over 12 inches in some localities. Heavy snow fell in the higher mountains and in the foothills later in the period. The saturation of the soil resulted in numerous rock and landslides…and the heavy run-off caused severe damage along many streams and flooding on the South Platte River. Many foothill communities were isolated as highways were blocked and communications disrupted. Roads were severely damaged over a wide area…and a large number of bridges washed out. Many roads were closed due to the danger from falling rocks. A building in Georgetown collapsed from the weight of heavy wet snow. In Boulder…a man drowned when caught by the flooding waters of Boulder Creek…and a patrolman was injured. Rainfall totaled 7.60 inches in Boulder with 9.34 inches recorded at the public service company electric plant in Boulder Canyon. In Morrison…rainfall totaled 11.27 inches in 4 days. Heavy rainfall totaled 4.68 inches at Stapleton International Airport over 3 days from the 5th through the 7th. Rainfall of 3.14 inches was recorded in 24 hours on the 6th and 7th. Downstream flooding continued along the South Platte River until the 12th when the flood crest reached the Nebraska line.

5

In 1903…apparent post-frontal northeast winds were sustained to 48 mph with gusts to 60 mph.

In 1950…a northwest wind gust to 52 mph was recorded at Stapleton Airport.

In 1969…a funnel cloud was observed for 2 to 3 minutes just north of Parker. Two other funnel clouds were sighted in the same area. The public sighted a tornado 15 miles east of Stapleton International Airport. No damage was reported.

In 2012…severe thunderstorms produced damaging hail ranging in size from quarters to golfballs in metro Denver including: Aurora…Centennial…Cherry Creek…Englewood… And southeast Denver. Aurora was hit the hardest…with extensive property damage reported to homes and automobiles.

5-6

In 1907…rain changed to snow on the 5th… Continued through the night…and totaled 3.50 inches. Northeast winds were sustained to 15 mph on the 5th.

In 1917…post-frontal rain changed to heavy snow and totaled 12.5 inches over downtown Denver. Most of the snow… 12.0 inches…fell on the 5th and this was the greatest 24-hour snowfall ever measured during the month of May. This was also the only measurable snow of the month that year. Low temperatures of 27 degrees on the 5th and 23 degrees on the 6th were record minimums for the dates. High temperatures on both days were in the lower 40`s. Southeast winds were sustained to 24 mph with an extreme velocity to 26 mph.

In 1964…high winds gusted to 54 mph in Boulder and to 80 mph at Jefferson County Airport near Broomfield. Wind gusts of 50 to 60 mph were common over all of eastern Colorado. Buildings…power lines…trees… And vehicles were damaged by the wind. South-southwest wind gusts to 54 mph caused some blowing dust at Stapleton International Airport where the visibility was briefly reduced to 2 miles.

In 1973…a heavy driving rain storm with embedded thunderstorms…produced 1 to 5 inches of rain and caused local flash flooding along the east slopes of the Front Range. The greatest flash flooding occurred in metro Denver where rainfall totaled 3.56 inches at Stapleton International Airport. Flooding in metro Denver occurred on Clear Creek and the South Platte River…already swollen from heavy snowmelt. Numerous basements were flooded… Roads and streets were washed out…a bridge was demolished… And miscellaneous other damage was reported. North winds gusted to 39 mph at Stapleton International Airport during the storm. The storm produced major downstream flooding along the South Platte River all the way to the Nebraska border during the next two weeks. One person died and total damage was estimated at around 120 million dollars.

In 1978…heavy wet snow of around 24 inches collapsed an office and hotel building in Boulder. Many cars were abandoned in the city. Denver received 14 inches of heavy wet snow with Evergreen and Golden reporting 12 inches. Snowfall totaled 12.4 inches at Stapleton International Airport with a total accumulation of snow on the ground of 8 inches due to melting. Southeast winds gusted to 23 mph on the 5th. Temperatures both days remained in the lower to mid-30`s.

6

In 1876…heavy snow fell during the night and ended during the morning…but no amount was recorded. Light hail fell briefly during the late afternoon. Precipitation for the day totaled 1.05 inch which would give an estimated snowfall of nearly 11 inches had all of the precipitation been snow.

In 1889…northwest winds were sustained to 45 mph in the city.

In 1893…heavy snow of 8.9 inches fell over downtown Denver. Once on the ground…the snow melted rapidly. This was the only snow of the month. Northwest winds were sustained to 20 mph.

In 1904…west winds were sustained to 45 mph with an extreme velocity to 46 mph.

In 1914…an apparent dry microburst produced sustained north winds to 44 mph with gusts as high as 50 mph.

In 1920…a thunderstorm produced hail and 0.55 inch of rain. The hail of unknown size covered the ground.

In 1921…thunderstorm winds were sustained to 42 mph with gusts to 44 mph. Rainfall was only 0.17 inch.

In 1936…a light to moderate duststorm moved in from the east on southeast winds and lasted most of the day. The dust reduced the visibility to two miles at times. Winds from the northwest sustained to 21 mph swept the dust out of the city during the late afternoon.

In 1966…a funnel cloud was sighted for 7 minutes to the southwest of Stapleton International Airport. The funnel appeared to be picking up dust from the ground…but was too distant to tell. No damage was reported.

In 1968…a thunderstorm wind gust to 53 mph was recorded at Stapleton International Airport.

In 1988…high winds raked the state. Wind gusts ranged from 60 to 80 mph in Boulder…Aurora… And at Centennial Airport. South-southwest winds to 53 mph were recorded at Stapleton International Airport. Across metro Denver…the strong winds knocked windows out of buildings…downed power poles and wires and some fences…unroofed several buildings… And damaged signs.

In 1997…strong winds from a dry microburst blew an empty 18-wheeler on its side in the northbound lane of I-25 north of Denver near the Brighton exit. There were no injuries. West winds gusted to 46 mph at Denver International Airport.

In 2017…lightning struck dangerously close to a woman while she watched a youth baseball game. She felt her legs go numb after a lightning bolt struck the ground.

6-7

In 1873…snowfall totaled 8.9 inches in downtown Denver. Most of the snow fell on the 6th.

7

In 1904…west winds were sustained to 48 mph with gusts to 60 mph. A shower produced 0.16 inch of rain.

In 1953…a microburst caused a brief wind gust to 58 mph at Stapleton Airport.

In 1958…3/4 inch diameter hail fell over south metro Denver… 10 miles southwest of Stapleton Airport.

In 1977…baseball size hail damaged windows in Wheat Ridge. Hail was 4 inches deep on the ground in Arvada. Hail 3/4 to 1 inch diameter fell in Westminster and Kittredge.

In 1990…a fast moving cold front produced wind gusts of 40 to 60 mph. Brighton reported a wind gust to 57 mph…while north wind gusts to 44 mph were measured at Stapleton International Airport.

In 1995…severe thunderstorms struck Aurora. Hail piled 4 to 5 inches deep in the vicinity of Quincy Reservoir in south Aurora. Lightning struck an Aurora police communications tower causing significant malfunction to the primary system. Minor damage was sustained when lightning struck an apartment building. Hail…up to 1 1/4 inches in diameter…while soft and slushy… Accumulated up to 6 inches deep in 15 minutes. Many streets were closed for an hour or more due to flooding caused by heavy rain and melting hail stones. Some trees were stripped of their leaves. Hail as large as 1/2 inch diameter was measured at Denver International Airport where a funnel cloud was sighted.

In 2003…a tornado touched down briefly near Bennett… But did no reported damage.

In 2005…severe thunderstorms produced 3/4 inch hail near Brighton and a thunderstorm wind gust to 60 mph near Fort Lupton.

In 2014…severe thunderstorms produced large hail… From 1 to 1 1/2 inches in diameter…across parts of Arvada…Broomfield… Dacono…Northglenn and Thornton.

In 2015…a severe thunderstorm produced hail…up to walnut size…in Elbert County. A weak tornado touched down briefly near Ft. Lupton.

In 2017…a 37-year-old woman and her horse were killed near Sedalia after lightning hit a nearby tree. A teenage girl was also seriously injured. Damaging microburst winds downed trees and power poles across parts of Adams…Arapahoe…Denver and Douglas Counties. Electrical lines and branches were also snapped causing scattered power outages.

7-8

In 1958…rainfall totaled 2.50 inches at Stapleton Airport.

8

In 1873…a very light rain fell until 5:00 am… When it turned into light snow and sleet and was accompanied by brisk northeast winds. The snow froze as it fell… Breaking the telegraph lines in many places. Precipitation totaled only 0.14 inch in the city.

In 1883…a severe rain and hailstorm struck the city. In 25 minutes the hail was 5 inches deep in the vicinity of the weather office in downtown Denver and reported as deep as 10 to 12 inches in other parts of the city. Gutters were blocked by the hail…and many cellars were flooded. Precipitation from the storm was 1.90 inches with the total for the day recorded at 2.02 inches. The size of the hail was not recorded.

In 1988…a wind gust to 68 mph was recorded at Echo Lake. Northwest winds gusted to 35 mph at Stapleton Airport.

In 1995…high winds of unknown strength blew a camper shell from the back of a pickup truck near Fort Lupton. North winds gusted to 49 mph at Denver International Airport.

In 1996…1 to 2 inch diameter hail was measured in Lochbuie northeast of Denver. Bean size hail fell in Brighton. The large hail fell from severe thunderstorms to the northeast of metro Denver.

In 2003…tornadoes touched down briefly near Brighton… Watkins…and Strasburg… But did no reported damage. Hail to 3/4 inch in diameter was measured near Hudson.

In 2017…severe thunderstorms broke out across Denver and the surrounding metro area and produced large damaging hail…strong winds…heavy rain and flash flooding. Hail up to baseball size…caused extensive property damage to cars…homes and businesses across a large part of Denver and the western suburbs including Arvada…Lakewood and Wheat Ridge. According to the Rocky Mountain Insurance Agency Association…the storm was Colorado’s most expensive insured catastrophe…around $2.3 billion. The group estimated more than 150000 auto insurance claims and 50000 homeowner insurance claims would be filed. Businesses and homes sustained holes in siding along with broken windows and torn screens. Severe thunderstorm producing large hail…strong winds and heavy rain impacted areas around Greeley as well. The high cost incurred from the storm was due to a number of factors including: the size of the hail…the densely populated area…the time of day…the escalating costs to repair high-tech cars…and more expensive homes. Colorado Mills Mall in Lakewood was severely damaged after hail busted skylights and caused flooding inside stores. The common areas and tenant spaces suffered substantial water damage. Extensive damage to electrical systems…mechanical systems… including HVAC and lighting…were expected to keep the mall closed for several months. In Lakewood…the loss in sales tax was projected to be about $350000 per month…which was 3 to 4 percent of the city`s monthly budget. Prestige Imports in Lakewood which sells Audis and Porches…250 to 300 vehicles were impacted by the storm. Some of those vehicles were valued at nearly $200000 each. Significant damage was reported at Lutheran Medical Center after the hailstorm tore through Wheat Ridge. The hospital building and some of the medical office buildings sustained broken windows. The storm also hit the office of the Colorado Bureau of Investigation in Lakewood. The offices were flooded…several cubicles destroyed…and even some ceiling tiles fell off. The storm damage prompted school officials to close all thirteen Adams 12 Five Star schools in Commerce City and Beach Court Elementary school in Denver. Most of the schools in the Adams 12 Five Star District were at least 50 years old and sustained flood damage. Large hail damaged an apartment building near Regis University… shattered windows and punctured the siding on the west- facing side of the building. Hail and heavy rain clogged drains and caused flash flooding throughout Greeley. Up to three feet of water covered the roadway near U.S. 34 and U.S. 85. Greeley firefighters helped several residents get out of garden level apartments that had flooded. Several other businesses and buildings suffered flood damage… including Greeley City Hall and an apartment complex in Evans. The Greeley Mall was extensively damaged when water poured into the mall from the roof and debris inundated the main floor.

8-9

In 1957…intense heavy rain caused flash flooding on toll gate creek in Aurora where 3 people were killed in a car. Up to 4 inches of rain fell in 5 hours in the toll gate creek basin. The rain also caused flash flooding on sand creek in Aurora and Denver. Rainfall totaled 3.29 inches at Stapleton Airport with most of the rain…2.34 inches… Occurring on the 9th.

8-10

In 1979…4.3 inches of snow fell at Stapleton International Airport where northwest winds gusted to 30 mph on the 8th. Most of the snowfall…2.3 inches… Occurred on the 9th. High temperature of only 35 degrees on the 9th equaled the record low maximum for the date.

9

In 1875…a heavy windstorm swept across the city for most of the day. West-northwest winds averaged a sustained speed of 31 mph between 6:00 am and 3:00 pm. The peak wind was sustained to 45 mph at 9:50 am.

In 1918…post-frontal winds were sustained to 40 mph with gusts as high as 43 mph. Only a trace of rain fell.

In 1941…a tornado was noted at 2:20 pm to the northeast of downtown and was followed by another similar shaped cloud or dust roll estimated 3 miles behind. Thick dust followed with heavy gusts of wind. The temperature fell 15 degrees in 10 minutes following the twister. The mild tornado did little damage except to unprotected frame structures. Winds were sustained to 50 mph with the passing of the tornado at Stapleton Airport. It was visible to observers for 10 minutes and was lost from sight as it traveled east into huge rolls of dust. Hail and rain followed with a few hailstones as large as 1/2 inch in diameter downtown. No damage was reported from the hail. Thunderstorm winds sustained to 31 mph produced blowing dust downtown. Precipitation was only 0.07 inch.

In 1983…streams swollen by recent rain and snowmelt caused an earthen dam to collapse…washing out portions of State Highway 67 near Deckers in southern Douglas County.

In 1992…three boys…ages 11…12…and 16… Were struck by lightning while taking cover under a large tree during a thunderstorm in Jefferson County…just 7 miles northwest of Denver. The three were seriously injured.

9-10

In 1889…heavy rainfall totaled 2.15 inches in downtown Denver. The cold rain was mixed with snow at times overnight. Temperatures on the 10th ranged from a high of 38 degrees to a low of 32 degrees with north winds sustained to 22 mph.

In 2003…a late spring snowstorm hammered the mountains… Eastern foothills…and urban corridor. The heaviest snowfall occurred north of Interstate 70. The heavy wet snow caused damage to trees throughout metro Denver and downed power lines. About 40 thousand people along the urban corridor were without power. Storm total snowfall amounts included: 11.5 inches in Louisville… 8 inches in Boulder and Broomfield; 7 inches in Thornton…Broomfield…at Denver International Airport… And at the site of the former Stapleton International Airport; and 6 inches 4 miles east of Denver. Snowfall ranged from 4 to 9 inches across extreme southern weld County. In the foothills…15 inches of snow fell near Jamestown…9 inches at Rollinsville and Rawah… With 8 inches at Chief Hosa and atop Lookout Mountain. The snow was accompanied by thunder on the afternoon of the 9th at Denver International Airport where west winds gusted to 25 mph on the 9th and north winds gusted to 22 mph on the 10th.

In 2015…from the 9th to the 10th…a strong storm system brought heavy snow to areas in and around Denver. Moderate to heavy rain showers transitioned over to snow by early in the evening on the 9th. Heavy wet snow overnight caused many trees to break under the pressure of the sudden weight. Tree damage ranged from minor to significant…with old growth trees losing large limbs and new trees sustaining fatal damage. Power outages affected about 43350 Xcel Energy customers in metro Denver. The Intermountain Rural Electric Association also reported about 1000 power outages in the Strasburg areas. In the high country…CDOT shut down Interstate 70 between the Eisenhower Tunnel and Silverthorne due to multiple crashes.