The first part of June typically brings some of Denver’s most eventful weather of the year and we clearly see that in our look back at this week in Denver weather history. From many damaging hail and wind events to heavy rains that resulted in flooding and even the Southlands Mall tornado of 2009 it has been an eventful week in history.

From the National Weather Service:

1-4

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.

2-4

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-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 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.

4-5

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 1.0 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 member’s 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.

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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 2009…severe thunderstorms in Denver and the surrounding metropolitan area produced five tornadoes… Large hail…up to 3 inches in diameter…and damaging thunderstorm winds. The tornado that produced the most significant damage touched down in southeast Aurora… South of Buckley Airport; it moved south-southeast across open fields…some residential areas and damaged southlands mall. It was 100 yards wide with a storm track of approximately 5 1/2 miles. Southlands Mall had some roof and window damage…as well as wall damage to one of its restaurants. South of the mall…Lowe’s received some roof damage; lightweight sheds and other structures were also destroyed. Numerous homes and apartments suffered window damage…minor roof damage and there were a few broken garage doors. One resident…north of the mall…was injured when he was swept off his porch while attempting to photograph the tornado. He was found unconscious and bleeding in his front yard…with a dislocated shoulder…an injured neck…and numerous other injuries. In addition…the tornado flipped a trailer home. A man inside the trailer suffered minor injuries. In parts of Aurora and Centennial…thunderstorm winds blew down power lines and caused electrical outages. Approximately 8000 homes and businesses were without power for nearly two hours. Earlier in the day…a tornado touched down about 6 miles northwest of Northglenn and caused minor damage. It’s path covered approximately 1/2 mile. Several trees were downed in an open field. The tornado also damaged a metal fence and caused minor roof damage to a nearby residence. The third tornado touched down 7 miles east-northeast of Buckley Air Field and flipped a semi-trailer as it passed over interstate 70. Lastly… Two tornadoes touched down in northwest Elbert County. One tornado damaged several outbuildings…a residence…and downed several trees. In addition… Several horses were injured by flying metal debris. The other tornado touched down in open country. This day was the first in the series of eight to cause damage along the urban corridor. Damage to homes and property along the Front Range totaled $161 million during the 8-day span. The majority of the property damage was caused by hail; 21000 automobile claims and 13000 homeowner claims were filed.

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.

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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 2009…lightning struck an apartment complex…a veterinary hospital in Boulder and caused minor damage. Lightning also struck two oil tanks…one in Boulder and the other at Front Range airport north of Watkins. The oil tanks in both instances were set on fire and suffered extensive damage.

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 10^th 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.