With the end of summer and the arrival of fall, looking back at Denver weather history we start to see more mentions of snow.  It is of course not the only notable weather event this time of year.  We still have received severe thunderstorms, damaging winds, and 90 degree plus heat.

From the National Weather Service:

From the 25th to the 27th:

in 1996…an early season snowstorm brought heavy snow to the Front Range eastern foothills.  Snowfall totals included:  8 to 12 inches around Conifer…7 inches on Floyd Hill…and 6 inches at both bailey and Chief Hosa. Snowfall totaled only 4.7 inches at the site of the former Stapleton International Airport.  This was the first measurable snow of the season.  After the passage of a strong cold front…north winds gusted to 38 mph at Denver International Airport on the 25th.

From the 26th to the 28th: 

In 1936…the heaviest snowfall ever recorded in September and the heaviest snowfall ever recorded so early in the season dumped a total of 16.5 inches of snow on downtown Denver and 21.3 inches at Denver municipal airport.  The 15.0 inches of snow measured from 6:00 pm on the 27th to 6:00 pm on the 28th is the greatest 24 hour snowfall ever recorded in September.  This was the first snow of the season.  The snow was intermittent through the 26th…but continuous from early afternoon on the 27th to around midnight on the 28th…except for a period of rain during the afternoon of the 28th which contributed to a loss of depth on the ground.  The greatest snow depth on the ground downtown was 13 inches with 8 inches at Denver municipal airport.  There were no high winds with the storm and traffic was interrupted for only a short period.  The storm produced property damage estimated at 7 million dollars.  With trees and shrubs in full foliage…the leaves caught and held the heavy water-laden snow…until the branches snapped from the weight.  More than 3000 workmen were called to remove the debris and snow from the city.  The city firemen who were off duty…as well as all the reserves… Were asked to report to their stations.  All schools in the city remained open…but attendance was only 50 percent of normal.  Grade school students were sent home at noon on the 28th.  The early storm caught stockmen with many cattle still in higher ranges.  Warm weather followed the snow…which had all melted by the end of the month…except for a few inches in sheltered places.

On the 27th:

In 1877…smoke from heavy forest fires in the mountains spread over the city on upper wind currents.
 
In 1935…the first snow of the season was 2.8 inches in downtown Denver.  The low temperature dipped to 31 degrees for the first freeze of the season.

Continue reading September 27 to October 3 – This week in Denver weather history →

Looking back at this week in Denver history we start to see more of the signs that summer is coming to an end and fall and winter are right around the corner.  Summer-like severe weather can still occur but we also start to see more cold temperatures and occasions with snow become more prevelant.

From the National Weather Service:

20   

In 1921…an apparent Bora produced northwest winds sustained to 44 mph with gusts to 64 mph.
 
In 1955…hail stones 1/2 to 3/4 inch in diameter were reported across parts of the city of Denver.
 
In 1992…weather observers at Buckley Air National Guard base sighted two tornados southeast of the base.  The tornados were short-lived and caused no injuries or damage.

20-21

In 1963…heavy rain and hail caused local flooding in southeast Denver.  Thunderstorm rainfall was only 0.60 inch at Stapleton Airport on the 20th.
 
In 1983…the cold front on the 19th brought an unusually cold air mass into metro Denver for so early in the season.  The temperature dipped to a daily record minimum of 28 degrees on both days.
 
In 1995…a vigorous late summer storm brought the season’s first heavy snow to portions of metro Denver.  Millions of trees were damaged and power lines downed as 4 to 8 inches of heavy wet snow settled on fully leafed trees in the Boulder and Denver areas.  Branches snapped and trees split under the weight of heavy snow…downing power lines. Firefighters responded to numerous transformer fires. Around 100 thousand people were left without electricity in Boulder and Denver areas alone.  It took over a week to fully restore power to some areas.  Insurance claims were estimated to be around 6 million dollars to homes in metro Denver and about 500 thousand dollars in damage to automobiles.  It was estimated that about 80 percent of 125 million dollars worth of city owned trees in Denver were damaged.  Snowfall totaled 7.4 inches at the site of the former Stapleton International Airport where the greatest depth of snow on the ground was only 4 inches due to melting.  Temperature records were set on the 21st when the thermometer dipped to a record low reading of 27 degrees and climbed to a high of only 36 degrees… Setting a record low maximum for the date.  North winds gusted to 29 mph at Denver International Airport on the 20th.

Continue reading September 20 to September 26 – This week in Denver weather history →

Weather conditions in Colorado can of course vary greatly and we always see that in our weekly look back in the history books.  For this week, we see a dizzying array of weather events from record setting temperatures in the 90’s and summer-like thunderstorms with tornadoes to an early arrival of winter that brought a foot of snow!

From the National Weather Service:

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In 1899…west winds were sustained to 43 mph with gusts to 46 mph.
 
In 1928…northwest winds were sustained to 41 mph with gusts to 45 mph.
 
In 1937…an apparent dry microburst produced brief north winds sustained to 31 mph with gusts to 41 mph.  There was a trace of rain.
 
In 1982…torrential rains drenched both the foothills and plains from Denver north.  While the heaviest rain occurred north of Denver…just east of Denver 2 1/3 inches of rain fell in 5 hours along with hail that caused minor damage to a few airplanes.  Thunderstorm rainfall totaled 0.83 inch at Stapleton International Airport.
 
In 1993…an upper level system combined with a cold and moist upslope flow to bring the heaviest snowfall to metro Denver for so early in the season.  Snowfall from the storm totaled 5.4 inches at Stapleton International Airport; however…most of the snow melted as it fell leaving a maximum of one inch on the ground at any one time.  North winds gusted to 21 mph at Stapleton International Airport where a record low temperature of 33 degrees for the date was observed.
 
In 2002…Friday the 13th proved to be bad luck for several motorists when heavy thunderstorm rainfall caused flooding on I-25 in central Denver.  Water rose several feet under the Logan Street overpass…inundating several vehicles. Some motorists were rescued…while others simply waited atop their cars for the flood water to recede.  The highway had to be closed in both directions for about 3 hours.  The flooding was exacerbated by poor drainage due to the construction along the highway.  A 12-foot drainage pipe had not yet been installed beneath the underpass.  The deluge also flooded several businesses along Broadway.

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

Colorado weather is certainly varied and this week’s look back at weather history proves that.  We have seen everything from deadly lightning, hail and severe winds to even snow during the second week of September.

1-7  

In 1978…the temperature reached 90 degrees or more on seven consecutive days with the highest temperature…94 degrees… Recorded on both the 4th and 6th.

3-6  

In 1909…rainfall for the 4 days accumulated to 3.97 inches in Boulder…while in Denver rainfall totaled 2.45 inches on the 4th…5th…and 6th.

5-9  

In 1988…layers of smoke aloft from large forest fires in Yellowstone National Park completely obliterated the sun at times.  At Stapleton International Airport…surface visibility was reduced at times to 5 and 6 miles in smoke.

6

In 1940…a thunderstorm pelted the city with small hail. The storm produced some lightning damage.  One woman was stunned by a bolt which struck near her.  Heavy rain from the storm raised the level of Cherry Creek by more than 3 feet during the height of the storm.  Rainfall downtown was only 0.26 inch.
 
In 1988…strong winds blew down two houses that were under construction in Castle Rock.  Northwest winds gusted to 44 mph at Stapleton International Airport.
 
In 1993…a man was struck and killed by lightning while standing outside his home in unincorporated Arapahoe County 11 miles south of Denver.  Lightning also struck a cabin in Marshdale…20 miles southwest of Denver…which started a fire and damaged one room and a portion of the roof.
 
In 1995…hail as large as 3/4 inch in diameter fell in Coal Creek Canyon in northern Jefferson County.
 
In 2001…a thunderstorm dropped 3/4 inch diameter hail in Aurora near Cherry Creek.

Continue reading September 6 to September 12 – This week in Denver weather history →

As always, when looking at weather history we are reminded of the varied and sometimes dangerous weather conditions we have here in Colorado.  Our look this week we see high temperatures soaring to 97 degrees but also we see the earliest snowfall on record.

From the National Weather Service:

19-30

In 1875…grasshoppers appeared in great numbers at 10:00 am on the 19th.  Thousands landed on the ground.  The streets were literally covered with them.  Swarms of grasshoppers were seen on each day.  All gardens in the city were devastated…and in the countryside the grasshoppers were very destructive to ripened grain.  On the 30th the grasshoppers were so numerous as to almost darken the sun.

30

In 1981…60 mph winds were reported in Boulder.
 
In 2004…a severe thunderstorm produced hail as large as 1 inch in diameter in south Aurora near Cherry Creek.

31

In 1951…hail as large as 1 3/4 inches in diameter caused an estimated 300 thousand dollars damage in metro Denver. Hail as large as 1 1/2 inches in diameter was measured at Stapleton Airport.
 
In 1978…strong thunderstorm winds tore the roof off an apartment building in Aurora…downed trees…and damaged windows in Denver.  A microburst wind gust to 58 mph was recorded at Stapleton International Airport.
 
In 1985…a thunderstorm wind gust to 60 mph was clocked at Buckley Field in Aurora.
 
In 1997…hail to 1 1/4 inches in diameter was measured in Aurora.
 
In 2006…a female postal worker was struck and injured by lightning while delivering mail in Westminster.
 
In 2008…lightning struck a home in Brighton…damaging the roof and a bedroom.  The damaged totaled 20 thousand dollars.

Continue reading August 30 to September 5 – This week in Denver weather history →

Quite the interesting week in Denver weather history.  Swarms of grasshoppers are the most unusual item we see but there is plenty of standard severe weather including tornadoes, landspouts, hail, lightning and much more.

From the National Weather Service:

19-30

In 1875…grasshoppers appeared in great numbers at 10:00 am on the 19th.  Thousands landed on the ground.  The streets were literally covered with them.  Swarms of grasshoppers were seen on each day.  All gardens in the city were devastated…and in the countryside the grasshoppers were very destructive to ripened grain.  On the 30th the grasshoppers were so numerous as to almost darken the sun.

22-24

In 1987…some locations in metro Denver had a total 3-day rainfall of 2 to 4 inches.  Rainfall totaled 0.96 inch at Stapleton International Airport.

23

In 1900…northwest winds were sustained to 42 mph with gusts to 49 mph.
 
In 1921…a thunderstorm cloudburst produced 2.20 inches of rainfall in an hour over downtown Denver.  This is the greatest 1 hour rainfall on record at the official observing site in the city.  Precipitation totaled 2.93 inches…which is the greatest calendar day precipitation ever recorded in august.
 
In 1941…one man was killed by lightning about 2 miles from the official weather station in downtown Denver.
 
In 1962…a home near Boulder was destroyed by a lightning- caused fire.
 
In 1968…strong winds buffeted Boulder briefly during the early morning hours.  At the National Center for Atmospheric Research…winds averaged 55 mph with gusts to 85 mph.  Damage was minor.  Northwest winds gusted to 31 mph at Stapleton International Airport.
 
In 1977…lightning damaged at least 6 homes in Aurora.
 
In 2008…a landspout touched down near Westcreek in Douglas County.  One man was seriously injured when he tried to escaped several falling trees in his ATV.  One of the trees struck his back and broke two vertebra.  Another camper narrowly escaped injury.  Seconds after he back up his truck…a tree came down where it had been parked.

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

August is usually considered one of the calmer weather months in Denver but as our look back in weather history for this week shows, that isn’t always the case.  Thunderstorms and all their associated dangers – lightning, flooding, tornadoes and more – all present a very real danger even this time of year.

From the National Weather Service:

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In 1902…a thunderstorm produced west winds sustained to 48 mph with gusts to 60 mph…but only a trace of rain.
 
In 1952…a thunderstorm wind gust to 50 mph was recorded at Stapleton Airport.
 
In 1960…lightning struck a warehouse in central Denver… Causing 8 thousand dollars in damage to the building and stored electrical equipment.
 
In 1975…large hail…1 1/2 to 1 3/4 inches in diameter…fell about 4 miles north of Castle Rock.  Hail caused some minor damage in Aurora.  A funnel cloud was reported 25 miles east of Denver near Bennett.
 
In 1981…a tornado touched down briefly in open country just to the east of Aurora.  No damage was reported.
 
In 1982…a thunderstorm wind gust to 61 mph was recorded at Buckley Field in Aurora.  At the same time almost an inch of rain flooded and closed streets in south Aurora.  A women was hit by lightning just north of Denver.  A house in the area was also struck.
 
In 1985…a thunderstorm produced strong wind gusts over southern metro Denver.  One strong wind gust hit Cheery Creek Reservoir…capsizing a boat and drowning a man.  The wind gusts…clocked as high as 50 mph…also downed a few trees.
 
In 1989…1 3/4 inch diameter hail fell at Intercanyon in the foothills of Jefferson County.
 
In 1990…lightning caused minor damage to a south Aurora home.  No injuries were reported.
 
In 1994…strong thunderstorm winds caused damage in southern Weld County near Hudson and Fort Lupton.  Two mobile homes were destroyed and a few lost their roofs.  Up to 20 downed power poles and the destruction of two 115 thousand-volt towers caused widespread power outages.  Thunderstorm gust front winds from the north gusted to 48 mph at Stapleton International Airport.
 
In 2000…lightning ripped most of the roof from a home in southeast Aurora.  The bolt sparked a fire which destroyed the residence.  Damage was estimated at 250 thousand dollars.
 
In 2002…the temperature climbed to a maximum of 100 degrees setting a new record high for the date.
 
In 2003…a teenager was injured when he was struck by lightning while camping at Herman Lake…13 miles northwest of Georgetown.  The boy was knocked unconscious and suffered minor injuries.

16-19

In 1979…heavy thunderstorm rains on each of 4 consecutive days dumped a total of 2.62 inches of rain on Stapleton International Airport.  The heaviest rain…1.05 inches… On the 19th was accompanied by 1/4 inch diameter hail.

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

Denver and Colorado as a whole are known for their unusual weather.  This week in particular is notable for one extraordinary event in weather history – clouds of grasshoppers!

8-10 

In 1979…heavy thunderstorm rains on each of three consecutive days dumped a total of 2.22 inches of rain at Stapleton International Airport.  The heaviest rain… 0.95 inches…fell on the 9th.  Small hail to 1/8 inch diameter fell on the 8th.

8-13 

In 1875…clouds of grasshoppers were seen flying through the air on the prevailing winds during each day.

9    

In 1900…a thunderstorm produced west winds sustained to 47 mph with gusts to 55 mph…but only 0.01 inch of rain.
 
In 1902…a thunderstorm produced no rain and north winds sustained to 52 mph with gusts to 60 mph.
 
In 1934…heavy cloudbursts in the foothills near Kittredge and at the head of Mount Vernon creek caused flash flooding on both bear creek and Mount Vernon Creek at Morrison… Which resulted in 6 deaths and much property damage. The highway in Mount Vernon Canyon was destroyed by the flood waters.
 
In 1981…3/4 inch hail fell at Kittredge near Evergreen in Jefferson County.
 
In 1987…3/4 inch hail fell in Boulder and 9 miles northwest of Castle Rock.
 
In 1995…lightning struck a 16-year-old counselor in the back of the head while he and a friend were standing under a tree at the singing river ranch…7 miles west of Evergreen.  He stopped breathing…but his friend was able to summon help and they were able to revive him.  He was hospitalized for a few days and released.
 
In 1998…brief…weak tornadoes (f0) were sighted near Bennett and Roggen.  No damage was reported.  Hail as large as 1 inch diameter fell in Franktown with 3/4 inch diameter hail measured near Castle Rock. Thunderstorm winds gusted to 61 mph near Roggen.

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

On first glance our look at this week in Denver weather history appears to be less eventful than many we have looked at previously.  However, the severity of the events that appear on the historical weather calendar this week are enough to make you stand up and pay attention.  While August is typically a pretty quiet weather month, it is clear that severe weather can certainly strike and Thornton is mentioned in more than one significant event.

From the National Weather Service:

2    

In 1878…the high temperature reached 100 degrees in downtown Denver.
 
In 1911…an apparent dry microburst produced sustained west winds to 42 mph.
 
In 1972…one workman was killed and another injured when a strong gust of wind destroyed a partially completed apartment building in south Denver.  Hail to 1 3/4 inch diameter fell in Golden.
 
In 1973…hail to 3/4 inch diameter was reported in Boulder.
 
In 1986…a major outbreak of severe thunderstorms occurred along the Front Range.  Thunderstorms developed explosively.  Some places were hit by large hail twice. Two inch diameter hail broke car windows on I-25 west of Brighton…and up to 1 1/4 inch hail broke windows in Thornton.  Baseball size hail damaged several planes near Watkins.  Funnel clouds were sighted around Aurora.  Hail over 1/2 inch in diameter covered the ground 3 to 4 inches deep at Hudson northeast of Denver.  Most of the hail fell north of metro Denver…but 3/4 inch diameter hail was measured at Stapleton International Airport.  Total damage from the hail storms this day was estimated at over 10 million dollars.
 
In 1991…late afternoon thunderstorms produced heavy rain across metro Denver.  Two feet of water covered parts of I-25 in southeast Denver…while one foot of water covered parts of U.S. Highway 285 in Englewood.  Thunderstorm rainfall totaled 0.50 inch at Stapleton International Airport.
 
In 2001…severe thunderstorms producing heavy rain and hail… Either washed out or damaged several County roads in the Watkins and Bennett areas.  A small tornado (f0) touched down near Bennett…but did no damage.  Hail as large as 1 3/4 inches in diameter fell near Watkins.  One inch diameter hail was measured near Hudson and Keenesburg.
 
In 2008…strong winds blew several trees down in Denver… Damaging homes and downing power lines.  A peak wind gust of 67 mph occurred at Centennial Airport…with gusts to 60 mph estimated in Denver.  A peak wind gust of 37 mph was measured at Denver International Airport.  An elderly man was killed when a wind damaged tree broke free and crushed him while he attempted to remove it.  The downed power lines caused outages to about 500 Xcel energy customers.

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

Weather can be deadly – we are all well (hopefully) aware of that.  Looking at this week in Denver weather history we are reminded of that and the tragedy that weather can bring to our state.  We see numerous cases of lightning causing death and injury but no one incident highlights the dangers of weather more than what occurred on July 31, 1976.  The Big Thompson Flood was Colorado’s worth weather-related disaster and claimed 144 lives.  More details on all these events are below.

13-5 

In 2008…a streak of 26 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.

26   

In 1891…a thunderstorm produced sustained northeast winds to 44 mph with gusts to 60 mph and 0.16 inch of rain.
 
In 1894…a thunderstorm produced sustained southwest winds to 36 mph with gusts to 58 mph…but only 0.04 inch of rain.
 
In 1910…the high temperature reached 100 degrees in downtown Denver.
 
In 1959…a Denver man was stunned while standing by a car that was struck by lightning.  He was treated for burns and shock at a local hospital.  Thunderstorm winds gusted to 55 mph at Stapleton Airport.
 
In 1983…two heavy thunderstorms hit the northern and western suburbs.  The first drenched Northglenn with an inch of rain in 30 minutes.  The second storm dumped an inch or more of rain in Idaho Springs and Evergreen.  The heaviest rainfall… 2.90 inches in an hour…caused minor street flooding in Golden.
 
In 1984…heavy early morning thunderstorms drenched the foothills southwest of Denver.  Rainfall to 1 1/2 inches in just 30 minutes occurred between Evergreen and Conifer.  In nearby turkey creek canyon…1.80 inches of rain was recorded in 35 minutes.
 
In 1985…a long rope-like white tornado touched down 5 miles east of Erie and stayed on the ground…mainly over an open field…for 18 minutes.  However…the twister damaged a few cars on I-25 and injured 3 people from broken glass.  The storm flipped over a van…blew out car windows…and ripped a highway sign.  It also blew an outbuilding off its foundation.  A tornado also touched down briefly 8 miles north of Bennett.  No damage was reported from this storm.
 
In 1988…a 9-year-old girl was slightly injured by lightning in Parker.
 
In 2003…a severe thunderstorm in and south of Franktown produced hail as large as 1.75 inches in diameter.

Continue reading July 26 to August 1 – This week in Denver weather history →