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:

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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 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.

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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.

Continue reading June 5 to June 11 – This Week in Denver Weather History →

There are many notable events on our look back at the weather history books for this week but one in particular stands out. It was 30 years ago this week, on June 3, that the infamous Thornton tornado struck. This twister still stands as the most damaging tornado to have ever struck the Denver metro area.

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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 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.

Continue reading May 29 to June 4 – This Week in Denver Weather History →

If history is a teacher, our look back at this week in Denver weather history should provide great instruction on the dangers severe weather presents in our history. It was three years ago this week that the infamous Windsor tornado tore through the area killing one man and damaging hundreds of homes.

From the National Weather Service:

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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.

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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.

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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!

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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.

Continue reading May 22 to May 28 – This Week in Denver Weather History →