Colorado’s unofficial severe weather season is during the months of May and June.  However, as we look back in Denver weather history, we see that July can oftentimes hold its own.  Many occurrences of flooding, scorching heat, and even tornadoes have been recorded.  Most notably, this week marks the 24th anniversary of the Big Thompson Flood – Colorado’s deadliest weather disaster ever.

7-25 

In 1934…a streak of 15 consecutive days of 90 degrees ranked 5th on the list of hot streaks.  The record of 24 consecutive days was established in the summer of 2008.

13-5 

In 2008…a streak of 24 consecutive days of 90 degrees shattered the previous record of 18 consecutive days established in 1901 and 1874.   Ironically…no new single day record high temperatures were set in the month of July. In August however…a record of 104 degrees was set on the 1st…and another record of 103 degrees was set on the 2nd. In addition…a record low min of 70 degrees was set on August 2nd.

18-2 

In 1987…a streak of 16 consecutive days of 90 degrees ranked 4th on the list of hot streaks.  The record of 24 consecutive days was established in the summer of 2008.

20-25

In 1965…heavy showers and thunderstorms doused metro Denver with significant rain each day.  Rainfall for the six days totaled 5.16 inches at Stapleton International Airport. Massive rainfall occurred on the 20th…21st…and 25th… Flooding streets and basements and causing streams to overflow.  The heaviest rainfall…2.05 inches…at Stapleton International Airport occurred on the 25th.

24-25

In 2003…maximum temperature of 100 degrees on the 24th was a record high for the date.  Low temperature of 73 degrees on the 25th was a record high minimum for the date.

25   

In 1875…brief heavy rain and hail lasted only 5 minutes… But the 1/4 inch diameter hail covered the ground to a depth of 1/2 inch and made the streets look like there had been snowfall.  There was much crop damage…especially to corn…and some sheep were killed.  Precipitation totaled 0.51 inch in the city.
 
Continue reading July 25 to July 31 – This week in Denver weather history →

As we move further into summer, we see a decrease in traditional things associated with severe weather like tornadoes.  However, there is a corresponding increase in heavy rain as Colorado gets closer to its monsoon season.  We see many occurences of dangerous flooding as well as damaging hail, deadly lightning and more as we look back at this week in Denver weather history.

1-18 

In 1874…a streak of 18 consecutive days of 90 degrees tied for second with another streak that was later set in the summer of 1901. The record of 24 consecutive days was established in the summer of 2008.

6-23 

In 1901…a streak of 18 consecutive days of 90 degrees tied for second with another streak set in the summer of 1874. The record of 24 consecutive days was established in the summer of 2008.

7-25 

In 1934…a streak of 15 consecutive days of 90 degrees ranked 5th on the list of hot streaks.  The record of 24 consecutive days was established in the summer of 2008.

11

In 1872…heavy rainfall started at 4:00 pm and continued into the night.  The heavy rainfall damaged homes and buildings in all parts of the city.  Rainfall totaled 1.64 inches.
 
In 1888…the temperature reached 100 degrees in downtown Denver.
 
In 1954…the high temperature climbed to 102 degrees at Stapleton Airport.
 
In 1970…a girl walking in a park in southeast Denver received eye and facial injuries when lightning struck nearby.  Lightning also caused numerous power outages and heavy rainfall produced local flooding at several locations across metro Denver.
 
In 1974…large hail up to 1 1/2 inches in diameter fell in Thornton.
 
In 1990…the worst hailstorm in American history in terms of dollar damage at the time battered metro Denver.  Storm damage totaled 605 million dollars…as it cut a 5-to 10-mile wide swath from just southeast of Estes Park to northeast of Colorado springs.  Hail as large as baseballs (2.75 inches) pounded metro Denver.  Hardest hit areas were southeast Boulder County…the Jefferson County Airport in Broomfield… Arvada…east Wheat Ridge…southwest and south-central Westminster…west Thornton…northwest…west-central and downtown Denver…northeast and east-central Lakewood…just east of Littleton…portions of Arapahoe County west of I-25… And northern and central Douglas County near Castle Rock and franktown.  Golf ball to baseball size hail severely damaged roofs on thousands of homes and buildings…battered tens of thousands of automobiles…windows…signs…street lights…and traffic signals…stripped paint…awnings…and trim from buildings…punched holes in the roofs of two homes in Arvada…knocked out power and telephone service to thousands of homes and businesses…defoliated thousands of trees…ripped up greens and fairways on a number of golf courses…and severely damaged several aircraft tied down at Jefferson County Airport.  Hail the size of baseballs fell for several minutes in old town Arvada.  Later…golf ball size hail and heavy rain pummeled two northwest Denver amusement parks.  Hardest hit was Elitch Gardens amusement park where 47 people were injured and received treatment for bumps…cuts…and bruises at local hospitals.  Many of the injured were stranded on rides during the storm when power failed.  Hail clogged storm sewers…causing rain water to back up 3 to 6 feet deep on some roads and intersections in Arvada.  Several basements were flooded.  In some places hail was washed into drifts several feet deep.  In addition… The storm spawned 2 small tornadoes.  One touched down briefly in Lakewood near 6th avenue and Kipling Blvd….but did no damage.  In Castle Rock…a tornado (f1) did heavy damage to some homes and vehicles in the Founders Village development near Ridge Road.
 
In 2001…lightning struck two homes in Thornton.  Most of the damage was confined to the attics of both homes.  Hail as large as 3/4 inch in diameter fell in Keenesburg…Longmont… And near Boulder.

Continue reading July 11 to July 17 – This week in Denver weather history →

Closing out June and entering July our look back at this week in Denver weather history is marked by severe weather and scorching heat.  Damaging hail to dangerous lightning are two common occurrences as is record-setting heat waves.

From the National Weather Service:

21-3 

In 2002…the maximum temperature in Denver equaled or exceeded 90 degrees for 13 consecutive days…equaling the 5th longest such streak on record.  The record of 18 consecutive days was set during the summer of 1901.

26-27

In 1965…wind gusts to 38 mph were recorded in downtown Boulder…causing widespread minor damage.  A microburst wind gust to 41 mph was recorded at Stapleton International Airport.

27

In 1873…Pikes Peak was hidden from view by smoke from forest fires in the mountains to the southwest of the city.
 
In 1927…the temperature cooled to a low of only 72 degrees… The all-time record high minimum for the month.
 
In 1980…lightning injured 4 people on a baseball diamond in Broomfield.  The bolt seriously injured the pitcher while also striking (out) the batter…catcher and second baseman.
 
In 1987…a microburst wind gust to 53 mph was recorded at Stapleton International Airport.
 
In 1990…the temperature reached a high of 102 degrees… Setting a new record maximum for the date.
 
In 1993…thunderstorm winds gusted to 60 mph across parts of metro Denver.  A wind gust to 50 mph blew over a 30-foot canvas tent at an amusement park southeast of Denver. Fifteen people…mostly children…were injured.  Microburst wind gusts to 33 mph were recorded at Stapleton International Airport.
 
In 2002…heavy rain…up to 3/4 inch…fell across sections of the Hayman burn area near Cheeseman Reservoir.  Several forest service roads were washed out and many culverts were plugged by debris.
 
In 2004…heavy rain producing thunderstorms caused rock and mud slides across the overland fire burn area in Jamestown. An estimated 50 tons of sand…dirt…rock…and ash slid into town…filling a culvert under main street.  The slide covered 150 to 225 feet of Main Street.  The flood was produced by half an inch of rain in 30 minutes.  A deluge of very heavy rainfall from nearly stationary thunderstorms caused flooding and flash flooding problems over parts of Jefferson and Douglas counties.  An automated rain gage in Golden measured 3.60 inches of rainfall in one hour.  Numerous homes were flooded in Golden…including one that was 146 years old. The home was listed as a complete loss.  State Highway 93 had to be closed from the Pine Ridge subdivision to the Golden Gate Canyon Road.   At the height of the storm…about 4 feet of water covered State Highway 93 through Golden… Forcing its temporary closure.  Several intersections were also flooded and impassable.  Rock and mud slides were reported in Golden Gate Canyon State Park.  At the Deer Creek Golf Course at Colorado 470 and Kipling…the greens were completely inundated by floodwaters.  Some backyards near the golf course were partially washed out.  In Douglas County…water up to a foot deep covered the roadways in Roxborough State Park.  The Waterton Canyon Road also had to be closed due to high water.

Continue reading June 27 to July 3 – This week in Denver weather history →

Late June weather is usually relatively calm but when it turns severe, it can do so in spades.  Hail, flooding rains, tornadoes and more are not unusual.  This week in Denver weather history we see plenty of each of those including a hail storm in 1993 that damaged dozens of planes at Denver International Airport. 

19-21

In 1875…smoke from several large forest fires in the mountains was visible from the city on each of these days.

20

In 1888…northwest winds were sustained to 44 mph.
 
In 1956…a microburst caused a brief wind gust to 58 mph at Stapleton Airport.
 
In 1964…hail up to 1 inch in diameter was reported 1 mile north of Stapleton International Airport.  A 3 minute hail storm at both Stapleton International Airport and Lowry Field piled small hail to one half inch deep.
 
In 1967…a strong thunderstorm dumped 1.95 inches of rain in less than an hour at Stapleton International Airport and produced a wind gust to 54 mph.  The storm caused some flooding in east Denver and Aurora.  There was widespread flooding to streets…basements…and store buildings and automobiles.  Hail stones to 3/4 inch in diameter were measured at Buckley Field in Aurora.  A tornado touched down just south of Littleton…damaging a barn and killing several head of cattle.
 
In 1985…a wind gust to 61 mph was reported at Golden Gate Canyon in the foothills west of Denver.
 
In 1986…a man was killed by lightning at Highlands Ranch south of Denver.
 
In 1987…several tornadoes were sighted across metro Denver.  A tornado touched down briefly 5 miles west of Parker.  A tornado was sighted just north of Chatfield Reservoir.  A tornado just northwest of Watkins was on the ground for 15 minutes.  A tornado near Barr Lake was taped by a television news crew.  It had a double vortex and was on the ground for about 10 minutes.  In addition to the 4 tornadoes…severe thunderstorms dumped large hail across metro Denver.  One inch hail was reported in southeast Aurora; 3/4 inch hail fell at the Denver technology center…Buckley Field…and Franktown.
 
In 1992…several short-lived tornadoes occurred in the vicinity of Barr Lake.  No injuries or damages were reported.  A water spout was sighted over the southern end of Barr Lake.  Funnel clouds were also sighted on the grounds of the rocky mountain arsenal by national weather service observers at Stapleton International Airport.
 
In 1994…hail up to dime size covered I-25 south of Denver and near Sedalia.  Heavy rain caused local flooding on the interstate highway.
 
In 1996…strong thunderstorm winds downed several large tree limbs in Boulder on the University of Colorado campus.  A stop light in the city was also blown down.
 
In 1999…lightning sparked an oil tank fire near Brighton.
 
In 2001…large hail driven by strong thunderstorm winds raked Denver international and Front Range airports.  Wind gusting to 54 mph along with hail as large 2 inches in diameter punched at least 14 thousand holes and cracks in the flat roofs of several buildings at Denver International Airport. In addition…93 planes and hundreds of cars were damaged. About 100 flights had to be cancelled…stranding 1500 travelers.  The airport was completely shut down for about 20 minutes.  The storm also damaged a ground avoidance radar used to track planes on the ground to prevent collisions. Damage was estimated at 10 million dollars…not counting the damage to the 93 airliners.  The storm moved south and struck Watkins with hail as large as 2 1/2 inches in diameter and winds gusting to 60 mph.  A least 30 private planes at Front Range airport were destroyed.  The radome protecting the national weather service doppler radar…which was tracking the storm…also sustained damage.  The large hail…damaging winds…and heavy rain pummeled a mobile home park near Watkins.  In the park…52 mobile homes…14 recreational vehicles…3 homes…and a commercial building were damaged.  Siding was riddled with holes and windows were broken.  Vehicles sustained extensive damage and car windows were shattered.  A handful of people were treated for minor cuts and bruises.  The strong winds also flipped a tractor trailer along I-70 near Watkins.  The storm caused power outages…which affected about 1200 residents. Excluding the damage at Denver International Airport…damage estimates totaled 49 million dollars…making the storm the costliest in the last 3 years and the 10th costliest since 1984.  A small tornado touched down just east of Brighton… But did no damage.  Hail as large as 2 inches in diameter fell near Fort Lupton with 3/4 inch hail measured in Bennett.  Precipitation from the storm totaled only 0.23 inch at Denver International Airport.
 
Continue reading June 20 to June 26 – This week in Denver weather history →

June typically is a very eventful weather month and looking back at this week in Denver weather history that is clearly seen.  Among the more noteworthy items are the 2002 Hayman Fire, a 1965 flood that damaged dozens of bridges in the Denver area and the infamous tornadoes in 1988 that struck near downtown Denver. 

11-14

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.

12-17

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.

13

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.
 
In 2009…severe thunderstorms produced hail up to one inch in diameter near Arvada and byers…as well as 7 miles north-northwest of Front Range airport near watkins.

Continue reading June 13 to June 19 – This week in Denver weather history →

We are getting closer to Colorado’s severe weather season and see how dangerous it can be when we look back in Denver weather history.  Many occurrences of dangerous lightning, large hail, flooding and tornadoes have been the hallmark of this week in Denver weather history.

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.

21-23

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.

22-23

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.

Continue reading May 23 to May 29 – This week in Denver weather history →

Late spring typically brings some of the most eventful weather Denver sees throughout the year and our look back at this week in Denver weather history shows that.  There are many typical events we would expect to see such as hail, heavy rain and flooding, and even tornadoes.  Most notably, this week marks the two year anniversary of the Windsor tornado.  And, for those that think the snow is done, we can see that in 1983 a snowstorm struck the city forcing the closure of Stapleton International Airport.

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.

15-16

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.

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.

Continue reading May 16 to May 22 – This week in Denver weather history →

As we get further into spring our look back at Denver weather history begins to show more typical severe weather.  This week in Denver weather history we see plenty of hail, heavy rainfall, a tornado or two and lightning that caused serious injuries. 

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.

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.
 
Continue reading May 9 to May 15 – This week in Denver weather history →

As we enter the month of May, our weather history calendar is as eventful as ever however we start to see a transition with fewer snow events and more typical spring events.  Of note are many events that caused flooding, severe winds, tornadoes, and lightning.

29-2

In 1954…a major storm dumped 10.1 inches of snowfall at Stapleton Airport.  Most of the snow…7.5 inches…fell on the 29th and 30th.  The maximum snow depth on the ground was 5 inches on the 30th due to melting.  No strong winds accompanied the storm.

1-2

In 1903…post-frontal rain changed to light snow overnight… But totaled only 2.0 inches.  This was the last snow of the season.  Northeast winds were sustained to 45 mph with gusts to 48 mph on the 1st.

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  

In 1874…strong winds upset two railroad passenger coaches near Georgetown.  The baggage was retrieved and placed in a heavy…large wagon.  The passengers then seated themselves on top of the baggage.  Another strong gust of wind upset the wagon.  The driver’s shoulder was dislocated…and a passenger’s leg was badly injured. In Denver…northwest winds increased and blew in gusts and heavy winds were observed on the ridge tops.  On the Kansas Pacific R.R. east of Denver…the wind was so strong that it blew the train back several lengths…which caused the train to be about 7 hours late arriving in the city.
 
In 1901…south winds were sustained to 50 mph with gusts to 60 mph from an apparent thunderstorm with hail.
 
In 1944…snowfall of 8.3 inches was accompanied by a thunderstorm.  This was the last snowfall of the season and the only snow of the month.  Northwest winds were sustained to 25 mph.
 
In 1955…southwest winds at speeds of 37 mph with gusts as high as 58 mph caused some blowing dust at Stapleton Airport.
 
In 1983…1 inch diameter hail fell a few miles south of Bennett.
 
In 1984…3/4 inch diameter hail fell in Northglenn.
 
In 1988…I-70 east of Denver was closed for the second straight day…this time due to snow and blowing snow producing up to 2 foot drifts.  While only 2 to 4 inches of snow fell across metro Denver…Strasburg…just east of Denver…received a foot of snow.  North winds peaked to 51 mph at Stapleton International Airport where snowfall totaled only 1.3 inches.
 
In 1995…lightning struck a house in Westminster sparking an attic fire.

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.

Continue reading May 2 to May 8 – This week in Denver weather history →