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October 8 to October 14: This week in Denver weather history

This Week in Denver Weather History

Denver has yet to get a taste of wintry weather this year as we continue what has been a very dry period the last few months. In the past that hasn’t always been the case and our look back at this week in Denver weather history shows that heavy, winter-like snowstorms can and do strike in October.

From the National Weather Service:

7-8

In 1990…the season’s first snow occurred. Snowfall amounts varied from 3 to 7 inches across metro Denver. Snowfall totaled 4.0 inches at Stapleton International Airport where north winds gusted to 29 mph.

8

In 1923…southeast winds were sustained to 44 mph with gusts to 47 mph. The strong winds persisted through the afternoon. The high temperature of 77 degrees was the warmest of the month that year.

In 1975…a wind gust to near 100 mph was recorded in Boulder. Frequent wind gusts to 60 mph were reported along the foothills causing only minor damage. West winds gusted to 45 mph at Stapleton International Airport.

8-9

In 2017…an early season snowstorm produced heavy wet snow which broke branches and downed power lines. About ninety-eight thousand outages occurred in Denver and the surrounding metro area. Almost half the outages were very short…while 54210 were sustained outages that lasted longer than five minutes. Some however lasted for several hours. Snow amounts varied greatly along the Interstate 25 Corridor. West of I-25…storm totals included: 7.5 inches in Arvada…7 inches in Broomfield…6 inches Boulder and Louisville…with 5 inches at Ralston Reservoir. East of I-25…storm totals ranged from a trace to 4 inches. In the mountains and foothills…storm totals included: 12.5 inches near Genesee…10 inches at Eldorado Springs… Idledale and Nederland…with 8.5 inches near Jamestown.

9

In 1910…light smoke from forest fires in the mountains was sighted over the city.

In 1982…northwest winds gusted to 49 mph at Stapleton International Airport.

9-10

In 2005…a major winter storm brought heavy…wet snowfall to the Front Range mountains…eastern foothills…portions of metro Denver…and the Palmer Divide. Snow accumulations ranged from 8 to 26 inches with drifts from 3 to 4 feet in places. The heaviest snow occurred to the east and southeast of the city…closing most major highways in that area…including I-70 from Denver to Limon. The Red Cross opened four shelters for people who were stranded along I-70 in eastern Colorado. Since many trees had not yet shed their leaves…the storm caused significant tree damage. One woman in Denver was killed when a tree branch… 8 to 10 inches in diameter…snapped under the weight of the heavy…wet snow and struck her as she was shoveling her driveway. Xcel Energy reported power outages to about 35 thousand customers. Several incoming flights were delayed at Denver International Airport. Snow totals included: 16 inches in the foothills near Boulder…12 inches at Genesee and near Golden…22 inches near Watkins…19 inches near Bennett…17 inches southeast of Aurora…14 inches near Parker…13 inches near Castle Rock…12 inches in centennial… 11 inches in Parker…and 10 inches at Denver International Airport and in Littleton. While many areas of metro Denver received heavy snow…others experienced almost entirely rain. This included west and northwest metro Denver…Boulder…and Longmont. Rainfall amounts were significant as storm totals ranged between 1.50 and 2.50 inches. The steady rainfall triggered 3 rockslides in foothills canyons. Two of the slides occurred on State Highway 119 in Boulder Canyon and the longest slide…7 feet in length…on State Highway 74 in Bear Creek Canyon at Idledale. North winds were sustained to around 23 mph with gusts to 31 mph at Denver International Airport on the 9th. The high temperature of only 34 degrees on the 10th was a record low maximum for the date. The low temperature on both days was 32 degrees.

In 2019…a vigorous winter like storm system brought intense northerly winds and the cold front blasted through the urban corridor. Peak wind gusts from 50 to 60 mph accompanied the front. Some trees in Denver were uprooted by the strong winds. Light rain and drizzle overnight…changed over to the season`s first snow during the predawn hours of the 10th. Bands of moderate to heavy snow brought 2 to 6 inches of snow in the Front Range mountains…foothills and urban corridor. The morning commute was especially hazardous as falling temperatures froze wet roads. Multiple crashes occurred including: I-25 in Denver…I-70 from Denver west to the Eisenhower Tunnel and State Highway 285 towards Fairplay. Over 300 crashes were reported in Denver and Aurora alone. After reaching a maximum temperatures of 83 degrees on the afternoon of the 9th…the temperature plummeted to 13 degrees on the 10th. A temperature change of 70 degrees…the second largest 2-day swing for the month of October in Denver weather history. Continue reading October 8 to October 14: This week in Denver weather history

October 1 to October 7: This week in Denver weather history

This Week in Denver Weather History

October is usually a relatively calm weather month in Denver but can see some interesting events. In our look back at this week in Denver weather history we see tornadoes, damaging wind and of course snow.

From the National Weather Service:

30-1

In 1959…heavy snowfall totaled 5.9 inches at Stapleton Airport. Winds were light.

1

In 1892…the highest temperature ever recorded in October… 90 degrees…occurred. This is also the latest 90 degree reading of the season.

In 1898…southwest winds were sustained to 40 mph with gusts to 49 mph in the city.

In 1927…a trace of snow was the only snow of the month… Ranking the year…amongst several other years…the second least snowiest on record.

In 1971…a wind gust to 90 mph was recorded at Buckley Field in Aurora. The severe winds caused damage in northeast metro Denver. A brick wall of a bowling alley was blown down…the roof was blown off a garage…and some business signs were damaged. A man in the bowling alley was injured by flying glass. Northwest winds gusted to 43 mph at Stapleton International Airport.

In 1994…unusually strong thunderstorms for so late in the season pummeled metro Denver with large hail. The largest hail…2 inches in diameter…fell at Buckley Field. Hail 1 3/4 inches in diameter fell 7 miles northeast of Boulder and at Niwot. Hail 3/4 to 1 1/2 inches in diameter fell in Boulder…Arvada…Wheat Ridge…Edgewater…capitol hill and northwest Denver…Bennett…and Strasburg. Hail of unknown size damaged a Boeing 737 aircraft and injured both pilots at Stapleton International Airport when the windshield was broken out on takeoff. Half inch diameter hail fell at Stapleton International Airport where northwest winds gusted to 40 mph and rainfall totaled 0.82 inch.

In 2014…severe thunderstorms produced wind gusts to 60 mph across parts of Arapahoe and Denver Counties.  The intense wind gusts downed trees and power lines which caused a power outage near the Denver Technology Center.  At Denver International Airport…a peak wind gust to 37 mph was measured from the northwest.

1

In 2020…extreme drought conditions continued in October. The first half of the month remained unseasonably warm… dry and windy. These conditions allowed the fires to the west and northwest of Denver to explode and double in size. The Cameron Peak wildfire become the largest in the state`s history. The Calwood wildfire in Boulder County started near Jamestown…and consumed 8788 acres within a 24-hr period on the 17th. It consumed a total of 10105 acres by the end of the month. The Calwood wildfire also became the largest wildfire in Boulder County history. The fire damaged or destroyed a total of 26 homes with preliminary damage estimates of nearly 37 million dollars. Extremely poor air quality continued to plague Denver and the entire Front Range.

2

In 1903…southwest winds were sustained to 42 mph with gusts as high as 60 mph. The strong Chinook winds warmed the temperature to a high of 78 degrees.

In 1910…an apparent dry microburst produced sustained northeast winds to 43 mph.

In 1934…a trace of rain was the only precipitation of the month. This was the driest October on record.

3

In 1875…very dense haze hid the mountains from view as observed from the city.

In 1933…rainfall of just 0.01 inch was the only precipitation of the month. This was the second driest October on record.

In 1954…the low temperature cooled to only 60 degrees…the all-time record high minimum for the month October.

3-4

In 1969…the first snowfall of the season totaled 16.0 inches at Stapleton International Airport. There was a thunder snow shower on the evening of the 3rd…but otherwise little wind with the storm. The greatest snow depth on the ground was 8 inches due to melting. Heavy wet snow accumulated on trees…which were still in full leaf…and caused widespread damage from broken limbs and downed utility lines.

3-5

In 1984…the remnants of pacific hurricane Polo produced heavy rain over northeastern Colorado. Most locations received between 1.00 to 2.50 inches of rain…but 3.45 inches fell in Littleton. Rainfall totaled 1.73 inches at Stapleton International Airport…where north winds gusted to 24 mph.

4

In 1912…sustained south winds to 55 mph with gusts to 60 mph raised the temperature to a high of 83 degrees… The warmest temperature of the month that year.

In 1924…west winds were sustained to 46 mph with gusts to 50 mph in the city. The apparent Bora winds cooled the temperature to a high of 57 degrees from a high of 70 degrees on the 3rd.

In 2004…several small tornadoes touched down near Brighton… Barr lake…and Hudson in Adams and southern Weld counties. Most of these caused no damage. However…a small tornado 5 miles southeast of Brighton caused extensive damage to a recreational vehicle and severely damaged a barn. The barn was torn from its foundation…and the roof was thrown 100 feet. Four llamas in the barn were injured when it collapsed.

4-5

In 1997…unusually warm weather resulted in two temperature records. High temperature of 87 degrees on the 4th exceeded the old record set in 1922 by one degree. High temperature of 86 degrees on the 5th equaled the record set in 1990 and previous years.

5

In 1962…unusually severe thunderstorms for this late in the season affected areas from Boulder northward. Hail up to golf ball size and strong gusty winds did much damage to roofs…windows…and signs in Boulder. Heavy rainfall caused local flooding.

In 1994…lightning caused a power outage to over 2400 homes for a few hours in and around Nederland in the foothills southwest of Boulder. Very strong winds accompanied the thunderstorm. Thunderstorm winds gusted to 60 mph and hail to 1/2 inch diameter fell in Lafayette. Strong microburst winds gusting to 69 mph near Strasburg caused an oil rig to topple onto two vehicles…injuring one person. The strong winds in the area also downed a few power poles… But caused power outages to only a few homes.

In 1995…strong winds spread from the foothills onto the plains. Wind gusts to 77 mph were reported atop Squaw Mountain west of Denver. On the plains…winds gusted to 60 mph at Kennesburg and to 62 mph near Strasburg. North winds gusted to 41 mph at Denver International Airport.

6

In 1900…northwest winds were sustained to 40 mph with gusts as high as 50 mph in downtown Denver.

In 1903…northwest winds were sustained to 40 mph with gusts to 50 mph. The strong winds warmed the temperature to a high of 71 degrees in the city. The low reading was only 46 degrees.

In 1910…light smoke from forest fires drifted over the city.

In 1976…an arctic cold front brought light snow over the foothills above 6 thousand feet. Traffic was snarled at many locations. Only a trace of snow fell at Stapleton International Airport where rainfall totaled 0.20 inch and northeast winds gusted to 41 mph.

In 1991…the brilliant orange sunset was apparently the result of an extensive volcanic smoke layer in the upper atmosphere.

In 1994…strong west to northwest winds developed in the foothills above 9500 feet. A wind gust to 78 mph was recorded atop squaw mountain west of Denver and to 72 mph at Ward northwest of Boulder. Northwest winds gusted to 35 mph at Stapleton International Airport.

In 2011… Strong winds developed in and around the Denver area ahead of an approaching storm system. At the National Wind Technology Center, peak wind gusts ranged from 79 to 92 mph during the early morning hours. Across metro Denver, the strong winds toppled a few trees and damaged patio furniture. The wind caused a few flight delays at Denver International Airport due to a partial ground stoppage of incoming flights. Peak wind reports also included: 66 mph at Cedar Point, 63 mph at Denver International Airport, 60 mph at Buckley Air Force Base; 59 mph at Highlands Ranch; 58 mph at Deer Trail and Rocky Mountain Metro Airport in Broomfield; 55 mph at Bennett, Centenniel Airport and City Park in Denver.

7

In 1903…north winds were sustained to 40 mph with gusts to 48 mph.

In 1917…post-frontal northwest winds were sustained to 45 mph with gusts to 52 mph. Rain was mixed with a trace of snow…the first of the season. Precipitation totaled 0.22 inch and included the occurrence of hail… Even though no thunder was heard.

In 1950…strong winds caused a power outage in Boulder. This was the heaviest windstorm since January. Damage was minor. Northwest winds gusted to only 35 mph at Stapleton Airport.

In 1985…strong Chinook winds buffeted the Front Range foothills. Wind gusts between 60 and 70 mph were reported in Boulder and atop Squaw Mountain west of Denver. Southwest winds gusted to 41 mph at Stapleton International Airport.

7-8

In 1990…the season’s first snow occurred. Snowfall amounts varied from 3 to 7 inches across metro Denver. Snowfall totaled 4.0 inches at Stapleton International Airport where north winds gusted to 29 mph.

September 24 to September 30: This week in Denver weather history

This Week in Denver Weather History

Colorado’s famously inconsistent weather can be seen in our look back at this week in Denver weather history. Not only do we see damaging thunderstorms and winds but even major snowstorms that deposited more than a foot of the white stuff on the city.

From the National Weather Service:

23-24

In 2000…the first snowstorm of the season brought heavy snow to areas in and near the foothills. While the heaviest snow fell north of metro Denver…6 inches were measured in Boulder…4 inches at both Castle Rock and Morrison…but only 0.2 inch at the site of the former Stapleton International Airport where most of the precipitation fell as rain. At Denver International Airport where drizzle and rain fell on the 23rd… Snowfall during the early morning of the 24th was estimated at 2.1 inches due to melting. The foothills west of Denver received more snow with 10 inches measured at conifer…9 inches 11 miles southwest of Morrison… 8 inches atop Crow Hill…7 inches at Chief Hosa…and 5 inches at Ralston Reservoir.

24

In 1901…northwest winds were sustained to 50 mph with gusts as high as 57 mph in the city.

In 1932…thunderstorm rainfall of only 0.11 inch was the only measurable precipitation for the month that year in the city.

In 1986…a very strong wind storm roared across metro Denver. Boulder was hit hardest. Winds peaked to 131 mph at the National Center for Atmospheric Research. This is thought to be the highest wind gust ever recorded in Boulder during September. A wind gust to 118 mph was clocked on Davidson Mesa and to 92 mph near Niwot. Gusts of 70 to 80 mph were common over all of Boulder where an estimated 70 to 90 large trees were uprooted. About a dozen of them hit cars. Two walls of a building under construction were toppled and solar panels were blown off a house. Traffic lights and power lines were downed. Damage to power equipment alone was estimated at 100 thousand dollars. Wind gusts to 87 mph at Jefferson County Airport damaged two planes. A woman was seriously injured in Boulder. She suffered a fractured skull when struck by a falling tree limb. Trees were also downed in Louisville and Lafayette. West wind gusts to 45 mph were recorded at Stapleton International Airport.

25

In 1873…a fire was sighted in the woods near Platte Canyon… Probably caused by high winds blowing sparks among the timber.

In 1896…an apparent cold front produced northeast sustained winds to 40 mph with gusts to 48 mph.

In 1910…a thunderstorm produced sustained north winds to 51 mph. This was the highest recorded wind speed in the city in September at the time.

In 1936…a vigorous cold front produced a deadly dust storm in the city. North winds sustained to 36 mph with gusts to 38 mph produced much blowing dense dust…greatly restricting the visibility. The temperature plunged from a high of 84 degrees to a low of 38 degrees by midnight. The weather observer described the event with the following. “at 6:00 pm the temperature was 82 degrees and the wind velocity was only 4 mph; but with the wind shifting to the north and the barometer rising quite rapidly…the temperature fell sharply. By 6:30 pm…the wind velocity increased rapidly and by 7:00 pm had reached a maximum sustained velocity of 36 mph…bringing with it clouds of dust which had been picked up by gale force winds in southern Wyoming and northern Colorado…covering the city. The visibility was generally reduced to about 1/4 mile; however…the whirling of the dust down the streets and alleys…the visibility was at times somewhat less. Airplanes were grounded…traffic was halted at times…and homes filled with dust. The strong winds damaged electric power and telephone lines…leaving homes in darkness for a few hours in the city and for 18 hours in suburban towns and putting 2500 telephones out of service because of broken lines. An electric lineman was killed while repairing damage by the high winds. The dust storm was followed by rain that began falling at 10:55 pm…which turned to snow during the early morning hours of the 26th. A major snow storm followed on the 27th through the 29th.”

In 1999…high winds developed in the foothills of Boulder County. Winds gusted to 90 mph at Wondervu.

25-26

In 1908…apparent post-frontal rain changed to snow overnight and totaled 6.5 inches in downtown Denver. This was the first snow of the season. Precipitation totaled 0.76 inch. North winds were sustained to 39 mph on the 25th.

25-27

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.

26

In 1907…a late afternoon thunderstorm produced hail…0.23 inch of precipitation…and north winds sustained to 24 mph.

In 1927…snowfall of 1.7 inches…mixed at times with sleet… Was the first measurable snowfall of the season.

In 2012…a man was seriously injured when he was struck by lightning outside the Hebrew Educational Alliance as he and his family were getting in their car. The victim stopped breathing but was saved when his wife performed cardiopulmonary resuscitation on him immediately.

26-28

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. Continue reading September 24 to September 30: This week in Denver weather history

September 17 to September 23: This week in Denver weather history

This Week in Denver Weather History

The calendar may still say it is summer for a few more days but our look back at this week in Denver weather history shows that Old Man Winter can still make an appearance.

From the National Weather Service:

10-18

In 2018…the high temperature equaled or exceeded 90 degrees for 9 consecutive days; marking the first time such an occurrence has taken place in the month of September. It also brought September of 2018 into a 4-way tie for most 90 degree + days in the month. Previous years included 2017…2005 and 1895. During the streak…4 record high temperatures were either tied or broken…and one record high minimum temperatures was broken.

15-17

In 2000…unusually hot weather for so late in the season occurred when temperatures climbed into the 90’s setting daily record maximum temperatures on each of the 3 days. The high temperature was 92 degrees on the 15th and 95 degrees on both the 16th and 17th.

15-19

In 1906…rain on 5 consecutive days totaled 1.61 inches. A thunderstorm occurred on the 17th. High temperatures ranged from 48 degrees on the 16th to 65 degrees on the 15th. Low temperatures were in the lower to mid 40’s.

16-19

In 1971…a record breaking early fall snow storm caused extensive damage to trees and utility lines. The heavy wet snow occurred with little wind…but caused record breaking cold temperatures for so early in the season. Snowfall totaled 15.6 inches at Stapleton International Airport with most of the snowfall…12.0 inches…occurring on the 17th. This was the heaviest first snow of the season. The maximum snow depth on the ground was 13 inches. Record low temperatures were set on three consecutive days: 31 degrees on the 17th…23 degrees on the 18th…and 20 degrees on the 19th…which was also a new all-time record minimum for the month at that time. Record low maximum temperatures were set on 4 consecutive days: 48 degrees on the 16th…35 degrees on the 17th…40 degrees on the 18th… And 42 degrees on the 19th.

17

In 1873…brisk west to northwest winds at different times during the day…generally in sudden gusts…spread a good deal of dust into the city.

In 1953…strong winds caused thousands of dollars in damage to Boulder. The winds blew for most of the day with great gustiness…and a freak twister was reported during the afternoon. Damage was minor. A thunderstorm wind gust to 40 mph caused some blowing dust at Stapleton Airport.

In 1992…a tornado touched down briefly near Bennett. No damage was reported.

In 1993…severe thunderstorms rumbled across northern portions of metro Denver. Hail as large as 1 3/4 inches in diameter fell in Brighton. Dime size hail damaged several roofs of residences in Lafayette.

In 2000…for the second day in a row…the high temperature of 95 degrees at Denver International Airport broke three record temperature extremes: the high temperature broke the previous record for the day of 94 degrees set in 1895; it marked the warmest it has been for so late in the season; it also marked the 61st day in the year that the temperature had equaled or exceeded 90 degrees…eclipsing the record equaled the previous day and first set on September 29… 1994.

18

In 1901…northeast winds were sustained to 42 mph with gusts to 50 mph behind an apparent cold front.

In 1948…the low temperature cooled to only 69 degrees…the all-time record high minimum for the month.

In 1988…a strong cold front blasted metro Denver with high winds. Gusts reached 82 mph in Longmont and 81 mph at Jefferson County Airport near Broomfield where the winds flipped over and destroyed a small airplane. Wind gusts to 60 mph were recorded in Boulder and Wheat Ridge. West wind gusts to 54 mph were clocked at Stapleton International Airport. The strong winds downed trees and power lines and damaged homes and cars. A Longmont man was slightly injured…when a tree fell on top of his car.

In 1990…a slow moving thunderstorm over southwest metro Denver spawned an ominous looking funnel cloud near the intersection of Sheridan Blvd. and U.S. Highway 285. The funnel cloud nearly touched down a few times before lifting back into the main cloud. No damage was reported. Pea to marble size hail and 3/4 inch of rain fell over central and northeast Denver. Numerous streets and underpasses became flooded on Denver’s south side when the heavy runoff backed up storm sewers. Thunderstorm rainfall totaled 1.02 inches at Stapleton International Airport.

In 1993…a severe thunderstorm rolled through southeast metro Denver. Dime size hail was reported in many areas. Straight-line winds from the thunderstorm…measured by a weather spotter at 70 mph…tore the roof off 6 apartments of an apartment complex in Aurora. Heavy rain which accompanied the winds caused major damage to the apartments as well as the contents. Many trees…fences… And power poles were knocked down by the strong winds. Heavy rain flooded roadways in Denver and Aurora. Thunderstorm rainfall totaled 1.08 inches and north winds gusted to 44 mph at Stapleton International Airport where the visibility was briefly reduced to as low as 1/4 mile in heavy rain.

In 1996…a late summer snowstorm struck the northern mountains and Front Range eastern foothills. Golden Gate Canyon received 6 inches of new snow with 5 inches reported at both Nederland and Blackhawk. Thunderstorms produced heavy rain across metro Denver…which was mixed with snow by late evening. Rainfall totaled 0.83 inch at the site of the former Stapleton International Airport and 1.22 inches at Denver International Airport where northwest winds gusted to 39 mph. Continue reading September 17 to September 23: This week in Denver weather history

September 10 to September 16: This week in Denver weather history

This Week in Denver Weather History

Severe weather is less common as we enter the fall season but it is not entirely unheard of. As we see in our look back at this week in Denver weather history, we have seen everything ranging from torrential rains to tornadoes and even heavy snow.

1-30

In 2020…a worsening drought that started in the spring and continued through September. Outside of an early season snow on the 8th…the month of September was another unseasonably warm and dry period. The combination of hot…mostly dry conditions…and critically dry fuels… resulted in a continuation and rapid expansion of several massive wildfires. The Cameron Peak fire…which became the largest in the state`s history started on August 13th…and continued through September. As a result…very poor air quality continued to impact Denver and the entire Front Range. Denver recorded the most days ever with a high temperature of 90 degrees or better; 75 days. The last of which was 91 degrees on the 24th. The previous record was 73 days set in 2012.

5-13

In 2010…the Fourmile Canyon Wildfire…northwest of Boulder…broke out on the morning of the 5th. It originated from an unattended fire pit at a local residence. The wildfire quickly consumed 5 1/2 square miles or 3500 acres the first day…and forced the evacuation of over three thousand residents. Erratic 45-mph gusts sent the fire in two directions at times. Very dry weather conditions preceded the fire. The combination of strong winds…low relative humidities and dry fuels allowed the wildfire spread rapidly through the steep…heavily forested terrain. The flames were reportedly 20 to 50 feet in length. Towns within the burn area included Salina…Wallstreet and Gold Hill. The dry conditions coupled with gusty winds ranging from 45 to 64 mph persisted for several more days. Fire managers used as many as 700 firefighters and support personnel from 35 agencies and seven air tankers to battle the wildfire. A total of 6181 square acres or approximately 10 square miles were burned. The Fourmile Canyon Wildfire was the most destructive fire in Colorado history in terms of the damage to personal property. It destroyed 171 homes with an estimated cost of 217 million dollars.

9-10

In 1933…heavy rain over the Cherry Creek…Plum Creek…Big Dry Creek…and Little Dry Creek watersheds caused flooding on the South Platte River in Denver overnight. Nearly an inch of rain…0.98 inch…fell in the city.

In 1944…a trace of rain fell on each day. This together with a trace of rain on the 4th and 30th was the only precipitation for the month. The total of a trace of precipitation for the month equaled the driest September on record first set in 1892.

In 1994…unusually very warm weather resulted in three temperature records being equaled. High temperatures of 94 degrees on the 9th and 93 degrees on the 10th equaled record maximums for the dates. Low temperature of 63 degrees on the 9th equaled the record high minimum for the date.

10

In 1985…golf ball size hail was reported just east of Parker.

In 1989…3/4 inch diameter hail fell in Littleton. Heavy rain produced local flooding in Lakewood. The heavy rain caused the wall of a house to collapse.

In 1993…thunderstorm winds downed power lines…which caused a power outage in Castle Rock.

10-17

In 2018…the high temperature equaled or exceeded 90 degrees for 8 consecutive days; breaking the previous streak of 7 consecutive days in the month of September.

10-18

In 2018…the high temperature equaled or exceeded 90 degrees for 9 consecutive days; marking the first time such an occurrence has taken place in the month of September. It also brought September of 2018 into a 4-way tie for most 90 degree + days in the month. Previous years included 2017…2005 and 1895. During the streak…4 record high temperatures were either tied or broken…and one record high minimum temperatures was broken.

11

In 1910…west winds were sustained to 42 mph.

In 1951…a vigorous Canadian cold front produced a dust storm across metro Denver. Northeast wind gusts to 43 mph reduced the visibility at Stapleton Airport to as low as 1 1/2 miles for nearly 5 hours. The temperature dropped 47 degrees in 8 hours…from a high of 92 degrees to a low of 45 degrees.

In 1967…a microburst wind gust to 52 mph produced blowing dust and briefly reduced the visibility to 1/2 mile at Stapleton International Airport.

In 1974…a trace of snow…the first of the season…ended the shortest period without snow…94 days from June 9th through September 10th. A trace of snow also fell on June 8th.

In 1995…strong post-frontal winds associated with a fast moving pacific cold front knocked down power poles and trees as it moved through metro Denver. Numerous power outages affected nearly one thousand people in Denver and Jefferson counties. West winds gusted to 34 mph at Denver International Airport.

11-16

In 2013…a deep southerly flow over Colorado… Ahead of a nearly stationary low pressure system over the great basin… Pumped copious amounts of monsoonal moisture into the area. In addition…a weak stationary front stretched along the Front Range foothills and Palmer Divide.  This resulted in a prolonged period of moderate to heavy rain across the Front Range foothills…Palmer Divide…urban corridor. By the 14th…storm totals ranged from 6 to 18 inches… Highest in the foothills of Boulder County. The headwaters then moved down the South Platte River and caused widespread flooding with record flood stages at several locations as it made its way downstream.  The record high flood stages resulted in widespread flooding along the South Platte River basin. The flood damage encompassed 4500 square miles of the Front Range…left 7 dead… Forced thousands to evacuate…and destroyed thousands of homes and farms. Record amounts of rainfall generated flash floods that tore up roads and lines of communication… Leaving many stranded. Nearly 19000 homes were damaged… And over 1500 destroyed. Colorado department of transportation estimated at least 30 state highway bridges were destroyed and an additional 20 seriously damaged. Preliminary assessments of the state`s infrastructure showed damage of $40 million to roads and $112 million to bridges. Repair costs for state and county roads ran into the hundreds of millions of dollars. Miles of freight and passenger rail lines were washed out or submerged… Including a section servicing Amtrak`s iconic California Zephyr. The town of Lyons was isolated by the flooding of St. Vrain creek…and several earth dams along the Front Range burst or were over-topped. Floodwaters swept through Estes Park; damaged hundreds of buildings and destroyed large sections of U.S. 34 from Loveland and U.S. 36 from Lyons to Boulder. U.S. 34 suffered the most damage… With 85 percent of its roadway and bridges destroyed. In Weld County…about nearly two thousand gas wells were damaged and had to be closed off as the floodwaters inundated entire communities. Sewage treatment plants and other utilities were knocked out in a number of towns. Governor Hickenlooper declared a disaster emergency on September 13th…in 11 counties across northeast Colorado including:  Adams…Arapahoe…Broomfield…Boulder…Denver…  Jefferson…Larimer…Logan…Morgan… Washington and Weld. By the 15th…federal emergency declarations covered those counties as well as Clear Creek County. Projected losses from the flooding statewide was nearly two billion dollars in property damage…according to Eqecat… A catastrophe modeling firm.  The damage was most severe in and around Lyons and Boulder.  More than 11 thousand people were evacuated…reportedly the largest since Hurricane Katrina. President Obama declared a state of emergency for Boulder and Larimer counties.  An additional 10 counties were added on the 16th and included: Adams… Arapahoe…Broomfield…Clear Creek…Denver…Jefferson…  Morgan…Logan… Washington and Weld counties. The president also declared a major disaster specifically for Boulder County.  There were six fatalities directly attributed to flash flooding. Two 19-yr old teenagers died on the 11th…after they were swept away by floodwaters after abandoning their car on Lindon Drive in Boulder. In Jamestown…a 72-yr old man was killed when the building he was in collapsed. An 80-yr old Lyons resident died in the early morning hours of the 12th…when his truck was swept into the St. Vrain River near his home. Later on the 12th…a 79-yr old Larimer County resident was killed when she was swept away while trying to climb to safety from her home in Cedar Point. A 61-yr old cedar point resident died when her home was swept down the Big Thompson River by the floodwaters. An 80-yr old Idaho Springs resident drowned in Clear Creek when the embankment he was standing on collapsed. In Boulder…some of the monthly records broken included: one-day all-time record: 9.08 inches which shattered the previous wettest day of 4.8 inches set on July 31… 1919; one-month record of 18.16 inches…which broke the previous all-time monthly record of 9.59 inches set in May of 1995; wettest September on record which broke the previous record of 5.5 inches set in September of 1940; one-year record of 34.15 inches broke the previous wettest year of 29.93 inches set in 1995. At Denver International Airport…the total precipitation for the month of September was 5.61 inches…which was 4.65 inches above the normal of 0.96 inches. This is the most precipitation ever recorded in Denver for the month of September. Daily precipitation records included 1.11 inches on the 12th and 2.01 inches on the 14th.

11-12

In 1974…post-frontal rain changed to snow overnight for the first snow of the season. Snowfall totaled only 1.8 inches at Stapleton International Airport where north winds gusted to 40 mph on the 11th. High temperature of only 46 degrees on the 12th set a new record low maximum for the date. Continue reading September 10 to September 16: This week in Denver weather history

September 3 to September 9: This week in Denver weather history

This Week in Denver Weather History

The first full week of September sees us start one of the most pleasant times of year in Denver. While less common this time year, severe weather can and does occur. Our look back at this week in Denver weather history includes hail, damaging wind and even smoke from wildfires hundreds of miles away.

From the National Weather Service

1-5

In 1995…record breaking heat occurred on the first 5 days of the month when the temperature climbed into the 90’s on each day. Record high temperatures of 97 degrees on both the 1st and 4th equaled the all-time record maximum for the month. High temperature of 95 degrees on the 3rd was a record for the date. High temperatures of 94 degrees on both the 2nd and the 5th were not records. The low temperature of 64 degrees on the 4th equaled the record high minimum for the date.

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.

1-30

In 2020…a worsening drought that started in the spring and continued through September. Outside of an early season snow on the 8th…the month of September was another unseasonably warm and dry period. The combination of hot…mostly dry conditions…and critically dry fuels… resulted in a continuation and rapid expansion of several massive wildfires. The Cameron Peak fire…which became the largest in the state`s history started on August 13th…and continued through September. As a result…very poor air quality continued to impact Denver and the entire Front Range. Denver recorded the most days ever with a high temperature of 90 degrees or better; 75 days. The last of which was 91 degrees on the 24th. The previous record was 73 days set in 2012.

2-3

In 1892…there was a trace of rainfall each day. This… Together with a trace of rain on both the 7th and 8th…was the only rainfall of the month…making the month the driest on record. The monthly record was equaled in 1944.

3

In 1901…a thunderstorm produced rain…hail of unknown size… And south winds sustained to 40 mph with gusts to 43 mph.

In 1961…Labor Day snow storm is the earliest date of the first snow…trace and measurable…of the season. The heavy wet snow broke many limbs from trees that were still in full foliage. The storm produced 4.2 inches of snowfall at Stapleton Airport with nearly a foot of snow in western suburbs and in the foothills. Minimum temperature of 33 degrees was a record for the date and the coldest ever recorded so early in the season.

In 1999…severe thunderstorms dumped large hail across metro Denver. Hail as large as 1 inch in diameter was measured near Cherry Creek in Aurora and near Bennett. Hail to 3/4 inch in diameter fell in the city of Denver.

In 2002…a thunderstorm produced a wind gust to 51 mph at Denver International Airport.

In 2003…very heavy thunderstorm rain washed out parts of the Virginia Canyon Road above Idaho Springs. Up to 4 feet of mud reportedly washed down the road during the storm. Several vehicles were trapped on the road.

In Idaho Springs…several streets…including the main street… Were also buried in mud and gravel. Some buildings in town experienced minor flooding…including the basement of the town library and the police station.

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.

4

In 1909…apparent post-frontal heavy rainfall totaled 1.94 inches in downtown Denver. North winds were sustained to 19 mph.

In 1944…a trace of rain fell. This together with a trace of rain on the 9th…10th…and 30th was the only precipitation for the month. The total of a trace of precipitation for the month equaled the driest September on record first set in 1892.

In 1960…the highest recorded temperature in September…97 degrees…occurred. The same temperature also occurred on September 5…1899…September 1…1995…and September 4… 1995.

In 1989…a strong thunderstorm wind gust flipped a plane taxiing on a private runway in Adams County east of Denver. Two people were slightly injured and the plane was heavily damaged.

In 1992…strong winds developed across metro Denver behind a pacific cold front. Sustained winds above 40 mph with gusts as high as 60 mph were recorded mainly in and near the foothills. Pre-frontal south winds gusted to 37 mph at Stapleton International Airport.

In 1995…two people were injured when lightning struck their home in Lakewood. The lightning entered the attic where it started a small fire. It then traveled through the walls… Exploding a mirror and spraying glass on the residents. Lightning also sparked small grass fires near Aurora…Denver International Airport…and Bennett. The highest recorded temperature in September…97 degrees…occurred. The same temperature also occurred on September 5…1899…September 4…1960…and September 1…1995.

In 2000…thunderstorm winds gusted to 64 mph in Castle Rock.

5

In 1899…the highest recorded temperature in September…97 degrees…occurred. The same temperature was also reached on September 4…1960…and September 1 and 4…1995.

In 1940…a severe wind and hail storm confined mostly to the west and north parts of the city occurred shortly after 4:30 pm. Hail stones ranged in size from 1/4 to 1/2 inch in diameter. In north Denver…hail piled to a depth of 4 inches. Flooding occurred in one underpass…which stalled 2 cars. One girl was injured when the weight of the hail flattened a porch on which she stood. Northeast winds were sustained to 29 mph with gusts to 32 mph in downtown Denver.

In 1987…a thunderstorm complex produced hail as large as 1 3/8 inches in diameter…2 miles east of Buckley Field in Aurora. No damage was reported.

5-8

In 2020…a strong upper level low brought an end to record heat to the Front Range urban corridor…and provided Denver its second earliest measurable snowfall on record. Numerous heat records were set leading up to the snowfall…and several new snowfall and cold records were also broken in this abrupt bout with winter. Denver set its all time record high for September…reaching 101 degrees during the afternoon. This was also the latest date a 100 degree reading has ever been observed in Denver. Another daily record high was then tied on September 6th when Denver hit 97 degrees. September 7th was the last day of heat when Denver`s high temperature reached 93 degrees. That tied Denver for the record for the number of 90 degree days for a year at 73…and was also the warmest temperature ever recorded before a day of measurable snowfall. By the evening of September 7th…a series of cold fronts progressed southward from Wyoming into Colorado… dropping the temperature into the low 30s by the early morning hours of September 8th. Snow developed across the Front Range mountains and foothills overnight… while a mix of rain and snow developed along the I-25 corridor. A few locations picked up light snowfall accumulations in the morning. Accumulating snow was mostly confined to the higher elevations much of the day…before spreading across the plains during the late afternoon and evening. Storm totals ranged from 4 to 10 inches in the mountains…with 3 to 6 inches near the foothills. A total of 5.6 inches of snow was measured at the NWS Boulder office…while at Denver International Airport…the official measurement was 1.0 inch. Continue reading September 3 to September 9: This week in Denver weather history

August 27 to September 2: This week in Denver weather history

This Week in Denver Weather History

This time of year we usually see calm conditions as we begin the transition to fall.  However, that is not always the case as is seen in our look back at this week in history. Everything from thunderstorms with hail to tornadoes can and have been experienced.

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.

26-27

In 1980…two heavy thunderstorms hit Arvada and Westminster… Dumping up to 1.50 inches of rain in less than an hour. At least two streets were washed out and a number of homes and cars were damaged when a creek flooded. Three homes in Arvada sustained minor lightning damage.

27

In 1910…a thunderstorm produced south winds sustained to 40 mph.

In 1961…strong thunderstorm winds and heavy rain occurred at 79th and Federal Blvd. in Westminster. The strong winds blew the roofs off lumber sheds onto parked cars.

In 1967…a young woman was killed by lightning while horseback riding in the suburbs just west of Denver. Her horse died several hours after the incident. A young man and another young woman were also knocked from their horses by the impact of the lightning and required hospitalization.

In 1991…heavy thunderstorm rainfall totaled 0.91 inch at Stapleton International Airport…where 1/4 inch diameter hail was measured.

In 1996…localized street flooding occurred in the Fort Lupton area when 2 to 3 inches of rain fell in 45 minutes. The roof of a community college began leaking…which caused damage to ceiling tiles. The roof was under repair from hail damage which had occurred earlier in the summer. A weak tornado (F0) was sighted near Fort Lupton. No damage was reported.

In 1999…a slow moving thunderstorm dumped 5 inches of rain in 2 hours near Dacono. A severe thunderstorm produced 3/4 inch diameter hail in Castle Rock.

In 2002…severe thunderstorms spread large hail over metro Denver. Hail as large as 2 inches in diameter fell in Jefferson County 5 to 11 miles northwest of Golden. Other large hail reports included: 1 1/2 inches near Golden and in Lakewood; 1 1/4 inches in Nederland; 1 inch hail near Elizabeth…Louviers…Rollinsville…and Blackhawk; 7/8 inch hail near Acequia in Douglas County. A thunderstorm produced a trace of rain and a microburst wind gust to 52 mph at Denver International Airport.

In 2003…lightning struck a house and sparked a fire in Arvada. Damage to the roof and ceiling was extensive.

In 2005…lightning struck an unoccupied home in Parker. The resulting fire damaged the roof…attic…and second floor bedroom. Damage was estimated at 15 thousand dollars.

27-28

In 2004…a brief chilly spell resulted in three temperature records. The high temperature of 55 degrees on the 27th was a record low maximum for the date. The low temperature of 48 degrees on the 27th equaled the record minimum for the date. The low temperature of 42 degrees on the 28th was a record minimum for the date.

28

In 1887…a dry thunderstorm produced north winds to 48 mph but only a trace of rainfall.

In 1968…one man was seriously injured by lightning while riding on a roller coaster at a Denver amusement park. An airline employee was injured when lightning struck a jetliner he was servicing at Stapleton International Airport. A lightning-caused fire did extensive damage to one house and minor damage to several others in the city of Denver.

In 1970…a microburst wind gust to 53 mph was recorded at Stapleton International Airport.

In 2002…a severe thunderstorm produced 3/4 inch diameter hail near Parker.

In 2005…lightning sparked a small fire near Jamestown. The blaze was quickly contained and consumed less than an acre.

29

In 1876…after the passage of a gentle rain shower to the east during the late evening hours…the moon shone brightly and a remarkably bright lunar rainbow appeared.

In 1910…an apparent cold front produced sustained northeast winds to 40 mph.

In 1946…the high temperature warmed to only 55 degrees…the record low maximum for the month.

In 1989…a spectacular lightning display knocked out power to 300 blocks in southeast Denver. One bolt started a fire in a lumber yard in the northeast part of the city…and the attic of a home in the same area was set ablaze by a lightning bolt.

In 1996…3/4 inch diameter hail was measured in Parker.

In 2000…lightning struck two homes in Thornton. The extent of damage was unknown.

In 2002…two small tornadoes caused damage in southeast metro Denver. The first tornado…associated with a multi-vortex storm…touched down briefly near E-470 and South Jordan Road. Some fences were damaged…and a few trees were blown down. A few of the homes also sustained minor roof damage. Damage from this storm totaled 100 thousand dollars. The second tornado associated with the storm touched down in a subdivision that was under construction at Gartrell and Arapahoe roads. Four large condominiums under construction were destroyed. The most heavily damaged portions of the structures were still in the framing stages. Adjacent sections where enclosed walls were in place were not destroyed. A man suffered 4 broken ribs and several cuts and bruises when the trailer he sought shelter in was flipped three times and torn apart by the twister. Damage from this storm totaled 6 million dollars. A severe thunderstorm produced 1 inch diameter hail near Evergreen.

In 2006…severe thunderstorms produced large hail in the foothills west of Denver. Hail to 1 inch in diameter fell near Blackhawk. Hail as large as 7/8 inch was measured near Idaho Springs…along with 3/4 inch hail near Nederland and conifer. Continue reading August 27 to September 2: This week in Denver weather history

August 20 to August 26: This week in Denver weather history

This Week in Denver Weather History

Denver’s weather is not often boring. Lightning, hail, tornadoes and even swarms of grasshoppers have made appearances this week in Denver weather history.

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.

20

In 1980…winds to 55 to 60 mph were recorded in south Boulder.

In 1982…strong thunderstorm winds blasted the Jefferson County Airport near Broomfield…causing an estimated 3 million dollars in damage. At least 5 hangars and 15 airplanes were damaged…many seriously; one hangar was completely destroyed. Torrential rains accompanied the winds. Heavy rains also dumped on Boulder where 1.65 inches fell in just 15 minutes…causing street flooding. Wind gusts to 72 mph were recorded in Boulder. Over half an inch of rain fell in just 5 minutes in Littleton where two homes were struck by lightning. Lightning also struck a house in Arvada where over an inch of rain sent Ralston Creek over its banks. Strong winds accompanied the storms.

In 1984…slow moving thunderstorms dumped 1.25 inches of rain in Evergreen…causing street flooding. A half inch of rain fell in just 18 minutes in southeast Denver. Littleton and Boulder were also drenched with about an inch of rain. Rainfall totaled 0.92 inch at Stapleton International Airport.

In 2001…severe thunderstorms produced damaging winds and large hail across metro Denver. Hail as large 1 inch in diameter fell in Aurora near Cherry Creek. Strong thunderstorm winds gusting as high as 58 mph blew the roof from a building between Thornton and Denver and toppled several trees in Denver. One tree landed on a mail truck. Other thunderstorm winds were clocked to 60 mph near Parker… 62 mph in Broomfield…and 61 mph at Denver International Airport.

In 2006…a tornado (f0) touched down near Bennett…but caused no reported damage.

In 2013…severe thunderstorms pounded the southern Denver suburbs and other parts of the Front Range. In Jefferson County…water rescues were reported for some people in stranded cars. In the Ken Caryl area…large hail from one inch to 1 3/4 inches in diameter was reported. On West Chatfield Avenue in Jefferson County…hail runoff gathered six inches deep in spots and “hail plows” were sent out to clear some streets. Hail up to one inch in diameter was also reported near Castle Rock.

21

In 1876…heavy thunderstorm rain and hail struck the city. Hail stones as large as partridge eggs accumulated to a depth of 1 1/2 feet over eastern portions of the city. The heavy rainfall flooded streets and gutters. However… No significant damage was reported. Rainfall totaled 0.85 inch in central Denver.

In 1903…a thunderstorm produced west winds sustained to 42 mph with gusts to 48 mph.

In 1957…heavy thunderstorm rainfall and hail over the bear creek basin flooded portions of State Highway 8 in and near Morrison. There was also minor property damage in Morrison.

In 1995…a 68-year-old woman was struck by lightning while standing near a tree in Brighton.

In 2006…a severe thunderstorm produced 7/8 inch diameter hail in Franktown.

In 2019…severe thunderstorms produced hail up to 1 inch in diameter in parts of Arapahoe…Denver and Jefferson counties. Heavy rain and flash flooding…close to 2 inches in one hour…also accompanied the nearly stationary storms. In Denver…flash flooding caused several vehicles to be stranded at Martin Luther King Blvd and Dahlia Street. Highway 6 near Federal Blvd also flooded. Standing water up to 3 feet deep occurred in Park Hill. Lastly…water made its way into buildings north of Interstate 70. At Denver International Airport…just a trace of rainfall was recorded.

22

In 1898…an apparent thunderstorm produced southwest sustained winds to 40 mph with gusts to 43 mph.

In 1903…a late afternoon thunderstorm produced rain…hail… And east winds sustained to 40 mph with gusts to 44 mph.

In 1904…the lowest recorded temperature in August…40 degrees…occurred. The same temperature also occurred on three consecutive days…August 24…25…and 26 in 1910.

In 1965…heavy rain and hail caused some damage from flooding over northern Douglas County from Castle Rock to Franktown.

In 1981…thunderstorms moved across metro Denver. At least 5 funnel cloud sightings were reported. Funnel clouds were seen at 96th Ave. and Sheridan Blvd. And at 92nd Ave. and Federal Blvd. in Westminster and 7 miles north of Stapleton International Airport. Lightning injured two people in Boulder. A quarter inch of rain fell in just 5 minutes in Brighton. Up to 3/4 inch of rain doused Parker in 30 minutes.

In 1983…3/4 inch diameter hail was reported at Kittredge… Along with 0.60 inch of rain in 25 minutes.

In 1984…a thunderstorm dumped 4 inches of rain on Brighton in 90 minutes…causing extensive street flooding in the downtown area.

In 1987…over an inch of rain fell in 24 hours throughout most of metro Denver. A public library suffered water damage to the ceiling…carpet…and a few books. Rainfall was 0.76 inch at Stapleton International Airport.

In 1990…lightning knocked out power to about 2500 homes in Lakewood for about an hour.

In 1991…National Weather Service personnel at Stapleton International Airport sighted an apparent tornado briefly on the ground 3 miles west-northwest of the airport. No damage was reported.

In 1995…lightning struck 3 electrical power substations in Louisville. Residences of more than 4500 people were without power from 30 minutes to more than an hour.

In 1996…between 1 and 3 inches of rain fell across metro Denver. As a result…several low lying areas were flooded. A bicyclist was swept into a fast moving creek when he tried to cross a flooded bike path. The man was washed downstream about 15 feet before getting snagged by a tree stump. He and a man who tried to rescue him received minor injuries. The heavy rain caused numerous power outages…false fire alarms…and traffic accidents. In Lakewood…telephone service to around 60 thousand residents was knocked out when a switching center was flooded. Funnel clouds were sighted near Chatfield Reservoir and Highlands Ranch.

In 2000…lightning sparked a blaze which gutted a 10-unit apartment building in Highlands Ranch. Twenty-eight people were left homeless. Damage was estimated at 2 million dollars.

In 2007…severe thunderstorms produced large hail…up to 1 1/4 inches in diameter…in the vicinities of Castle Rock… Elizabeth and Franktown.

In 2013…flash flooding occurred in central Douglas County with numerous road closures reported. One of the closures occurred at the Tomah Road exit along I-25…south of Castle Rock.  The closure backed up all I-25 the way to Castle Rock. At Denver International Airport…1.94 inches of precipitation was recorded…which set a new record rainfall for the date. The old record was 0.75 inches… set back in 1953.

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.

In 2019…a severe thunderstorm produced large hail…up to 2 1/2 inches in diameter 5 miles west of Byers. Hail up to 1 3/4 inches in diameter was reported near Bennett.

24

In 1880…a thunderstorm produced vivid lightning and heavy rainfall…which caused flooding over the eastern part of the city including the brick yards. There was no rainfall recorded in downtown Denver.

In 1910…an apparent dry cold front caused a remarkable drop in temperature. From 3:00 pm until midnight the temperature fell from a high of 93 degrees to a low of 40 degrees. Northeast winds were sustained to 44 mph during the late afternoon.

In 1946…heavy rain near Idledale caused flooding on bear creek at Morrison…which resulted in one death when a woman was swept from her stranded car and drowned.

In 1973…strong winds blew down a few power lines and hail up to 3/4 inch diameter fell in southeast Aurora.

In 1984…heavy rain hit the south Denver area. Over an inch fell in less than an hour at both Castle Rock and Sedalia.

In 1992…heavy rains caused flash flooding across parts of metro Denver. Rainfall amounts of 1 to 3 inches fell with the hardest hit areas being the southwest and central parts of metro Denver. Bear Creek rose above bankfull near Idledale with flood waters moving into southwest metro Denver. Mud and rock slides along Colorado highway 74 west of Morrison were reported. The confluence of Cherry Creek and the South Platte River in downtown Denver also went out of its banks…flooding bike paths. Rainfall totaled 1.98 inches at Stapleton International Airport where light to moderate rain fell most of the day. Heavy rain and fog briefly reduced the surface visibility to 1 1/2 miles. The temperature climbed to a high of only 58 degrees…which was a record low maximum for the date.

In 2002…hail to 7/8 inch in diameter was measured in southwest Denver.

In 2008…several landspout tornadoes developed along a boundary to the southeast of the Denver metropolitan area during the Democratic National Convention. In northwest Elbert County… Minor damage was reported. The damage consisted of downed power lines…broken windows and an out building. Severe thunderstorms also produced very heavy rain and large hail… Up to one inch in diameter. In southwest Douglas County… Heavy rain caused flash flooding near the town of Westcreek. A mudslide closed State Highway 67. The road in the YMCA camp shady brook was also washed out and some bridges were damaged.

24-26

In 1910…the lowest temperature ever recorded in August…40 degrees…occurred on each of these days and on August 22… 1904. The unusually cold weather for so early in the season brought sub-freezing minimum temperatures to much of the Colorado northeastern plains.

25

In 1951…a microburst produced a southwest wind gust to 50 mph at Stapleton Airport. Only a trace of rain was observed.

In 1964…thunderstorm winds gusted to 59 mph and caused some blowing dust at Stapleton International Airport.

In 1994…lightning struck a power pole in Louisville and caused a two-hour power outage.

In 2008…an unoccupied home was struck by lightning in Aurora… Causing 75 thousand dollars in damage to the roof.

26

In 1944…one of the most destructive hailstorms in the city in a decade caused damage estimated at nearly one million dollars. The storm occurred within a period of 10 to 30 minutes…between 2:00 pm and 3:00 pm. The hail varied in size from very small to as large as 1 1/2 inches in diameter. Hail covered the ground to a depth of 5 to 6 inches in some sections of the city. Several people were cut by broken glass. The hail and heavy rain flooded underpasses to a depth of 6 feet…and the occupants of stalled autos had to be rescued. Sewers were unable to handle the sudden amount of water and water backed up and flooded a number of basements. A few first floors of buildings were flooded. The water department had a busy time replacing manhole covers that had been displaced by the water pressure. Trees were stripped…one was severely broken…and telephone lines were downed. Roofs…windows… Automobiles…awnings…and gardens were severely damaged. Flowers and gardens in some sections of the city were a total loss. Greenhouses were extensively broken with an estimated 20 carloads of glass shattered. Vegetable and truck crops in and around the city were severely shredded. The next day the American Red Cross was designated by the War Agency to grant any and all priorities needed to obtain materials and supplies to replace and repair the damage. In downtown Denver…the thunderstorm produced 0.95 inch of rain and heavy hail along with sustained northwest winds to 25 mph.

In 1961…strong winds blew in the walls of a warehouse under construction in Denver. Two workmen suffered a fractured foot and body bruises.

In 2014…two men in central Denver were struck by lightning as they sat under a tree to avoid a heavy downpour. One of the men was unconscious and had no pulse when emergency responders arrived. He was immediately taken to Denver Health was listed in critical condition. The other victim suffered less severe injuries. He was treated at the scene and hospitalized…then released a few hours later.

26-27

In 1980…two heavy thunderstorms hit Arvada and Westminster… Dumping up to 1.50 inches of rain in less than an hour. At least two streets were washed out and a number of homes and cars were damaged when a creek flooded. Three homes in Arvada sustained minor lightning damage.

August 13 to August 19: This week in Denver weather history

This Week in Denver Weather History

Severe weather is a fact of life in Colorado during the summer months and while August is historically relatively calm, that isn’t always the case. In our look back at this week in Denver weather history we see the dangers of lightning, incidents of large hail and flooding rains and even a tornado.

From the National Weather Service:

8-13

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

12-13

In 1975…heavy rains caused flash flooding along the foothills from Denver north. Thunderstorm rainfall totaled 1.56 inches at Stapleton International Airport.

In 2004…a brief cool spell resulted in two daily temperature records. The low temperature of 49 degrees was a record minimum for the 12th…as was the low temperature of 48 degrees on the 13th.

13

In 1959…thunderstorm winds gusted to 53 mph at Stapleton Airport.

In 1983…thunderstorms dumped torrential rain in Northglenn… Thornton…and Broomfield. Northglenn was drenched with 1.72 inches in 30 minutes. Street flooding was widespread. Hail…as large as 3/4 inch in diameter…was reported 7 miles northeast of Boulder along with heavy rain which caused some street flooding.

In 2000…lightning sparked 3 small grass fires near Golden. The fires were quickly contained. Hail as large as 3/4 inch in diameter fell in Castle Rock..

In 2019…Hail up to 1 3/4 inches in diameter was observed 4 miles west of Frederick…with hail up to one inch in diameter near Dacono.

14

In 1960…a bolt of lightning struck a man in Henderson… Causing serious burns.

In 1962…the temperature climbed to a high of 100 degrees at Stapleton Airport.

In 1968…a young man on a golf course in Denver was injured when lightning struck a tree under which he was standing. Lightning caused minor damage to a house in Denver. Heavy thunderstorm rain caused local street flooding. One inch diameter hail fell at Jefferson County Airport near Broomfield.

In 1973…winds as high as 85 mph damaged 20 aircraft at the Arapahoe County airport…now centennial airport.

In 1977…three tornadoes were sighted in Bennett. A man suffered a broken leg when hit by a flying board. He was outside his camper home…which was destroyed. All windows were broken in a near-by farmhouse where some shingles were ripped off and a 2 car garage was knocked down. Several vehicles were damaged and a cat…some rabbits…and chickens were killed. A broken oar from a boat was driven into the side of a house. A mobile home was overturned. One old barn was destroyed. Half a dozen homes and several agricultural buildings were damaged just west of State Highway 79.

In 1978…high winds produced much blowing dust…causing many traffic accidents in the Denver-Boulder area. Winds gusts of 70 to 101 mph were recorded. Northwest winds gusted to 44 mph at Stapleton International Airport.

In 1980…lightning hit two power poles in Littleton…causing 400 dollars in damage. Rainfall of 1.23 inches in a short time caused minor flooding…which included damage to a ground floor apartment and partially submerging a few vehicles in water. Thunderstorm rainfall totaled 0.98 inch at Stapleton International Airport.

In 1983…2.10 inches of rain drenched Golden in an hour with similar amounts in Lakewood and Boulder. Over ten thousand dollars worth of plants were washed away at a nursery in Lakewood.

In 1997…twelve motorists were injured in a multi-car accident when strong microburst winds estimated to 50 mph blew blinding dust across I-70 near Bennett.

In 1998…lightning struck a hydro-electric plant in Nederland… Causing a power outage. Residents in the foothills west of Boulder…including Nederland…Ward…Eldora…Jamestown… And Gold Hill…were without power for about an hour.

In 2006…heavy thunderstorm rainfall near Deckers washed away some the banks along State Highway 67 between Deckers and Westcreek. Several driveways on both sides of the highway were also damaged.

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In 1899…a thunderstorm produced southwest sustained winds to 43 mph with gusts to 46 mph.

In 1972…a pilot reported a funnel cloud briefly touching the ground in open fields…17 miles east-northeast of Stapleton International Airport.

In 1980…thunderstorm winds gusted to 55 mph in Boulder.

In 1982…brief heavy rain and winds estimated as high as 70 mph occurred in the conifer-Evergreen area. No damage was reported.

In 1990…lightning triggered a small attic fire in a house near Sedalia…20 miles south of Denver. A furious lightning storm caused widespread power outages across southern sections of metro Denver. One lightning bolt knocked out an electrical substation…causing a 90-minute blackout in southeast Denver affecting nearly 10 thousand homes and businesses.

In 2007…severe thunderstorms produced large hail…up to 2 inches in diameter…near larkspur. Extensive damage to vehicles in the area was reported.

In Parker…lightning struck a residence. The ensuing fire damaged the attic and top floor; causing $100000 in property damage.

In 2008…at least three homes were hit by lightning during the early morning hours in Arapahoe County. Lightning also struck two homes in Castle Rock…damaging the roofs. Continue reading August 13 to August 19: This week in Denver weather history

August 6 to August 12: This week in Denver weather history

This Week in Denver Weather History

As we get further into the month of August severe weather is less common. It can however still strike as we see in our look at this week in Denver weather history. Everything from torrential rains to massive hail and even a tornado have been reported.

From the National Weather Service:

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In 1877…a severe rain…hail…and wind storm struck Denver. The storm produced a one minute sustained wind speed of 75 mph. Rainfall totaled 1.00 inch in 25 minutes. The hail storm damaged vegetable gardens in the city.

In 1954…an unconfirmed tornado was reported in Westminster. A funnel cloud was sighted in the area…but it was not certain if it had touched down. No damage was reported.

In 1980…the temperature reached 100 degrees…setting a new record high for the date.

In 1982…3/4 inch diameter hail was reported in north Denver. Heavy rain caused street flooding in central Denver where 4 to 5 feet of water inundated I-25…closing the freeway for a while. Rainfall across metro Denver ranged up to 2.35 inches in just over an hour. An estimated 2000 basements were flooded. Only 0.01 inch of rain fell at Stapleton International Airport.

In 1991…heavy rain caused flooding at the junction of I-25 and I-70. Dime size hail was reported northeast of Boulder near Niwot.

In 1995…microburst winds gusting as high as 58 mph caused minor damage to an apartment complex in Broomfield. Some homes under construction were also damaged when the winds knocked over 2 by 4 wood beams along with some insulation and roofing materials…which broke a few windows. Microburst winds also overturned a camper near Barr Lake.

In 1996…hail ranging in size from 1 to 1 1/2 inches fell near Bennett.

In 2001…3/4 inch hail fell in the foothills near Conifer.

In 2008…a record daily rainfall record was set at Denver International Airport. The record of 1.29 inches in 24 hours broke the previous record of 1.10 inches set in 1929.

In 2020…a severe thunderstorm developed near Byers. The wind snapped large tree branches…up to 4 inches in diameter…and produce large hail up to one inch in diameter. At Denver International Airport…a peak wind gust to 47 mph was observed from the west.

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In 1948…a brief west moving tornado was sighted 3 miles north-northeast of Stapleton Airport. The white funnel silhouetted against a gray cloud background was very narrow…nearly vertical…and estimated at nearly 5 thousand feet high. A dust cloud formed on the ground around the funnel. No damage was reported.

In 1952…a thunderstorm wind gust to 52 mph was recorded at Stapleton Airport.

In 2014…severe thunderstorms produced large hail across western and southern parts of metro Denver. Near Centennial and Golden…hail up to quarter size was reported. Near Bennett…a peak thunderstorm wind gust to 65 mph was also reported. At Denver International Airport…a peak wind gust to 46 mph was recorded.

In 2018…a severe thunderstorm produced large hail around Denver and vicinity. Hail ranging in size from 1 to 1 3/4 inches fell near Firestone…Ft Lupton…Parker…and Smoky Hill. Continue reading August 6 to August 12: This week in Denver weather history