Tag Archives: August Weather

August 15 to August 21: This week in Denver weather history

This Week in Denver Weather History

While not as common this time of year, severe weather can still strike as we close out summer.  Most notable are the heavy rain events that can come along as a result of the monsoon season.  The dangers of these are oftentimes ignored and as we see can oftentimes turn deadly.

15

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.

In 2013…a dry microburst uprooted 30 to 40 large trees across a 12-block area of the Park Hill neighborhood in east central Denver. Several trees were snapped near the base along with numerous branches…8 to 10 inches in diameter. Power poles and lines were also downed with resulted in outages which affected seven hundred residents. One of the downed trees crushed a car`s hood… narrowly missing the driver. At Denver International Airport…a peak wind gust of 22 mph was observed from the southwest.

16

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 woman 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 15 to August 21: This week in Denver weather history →

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

This Week in Denver Weather History

Monsoon season in Colorado typically brings short-lived but heavy rains.  These can result in flash flooding and we see that in our look back at this week in Denver weather history.  Also notable are the number of lightning deaths and injuries as well as hail events and even a swarm of grasshoppers!

8

In 1874…swarms of grasshoppers invaded the city.  Millions of them were seen cruising through the air.  The insects were apparently picked up by a thunderstorm gust front and carried into the city.  The grasshoppers had ravaged crops in surrounding counties for the last month.

In 1878…the highest temperature ever recorded in Denver…105 degrees…occurred at 3:20 pm.  This temperature was equaled on July 20th in 2005.

In 1969…the temperature reached 100 degrees at Stapleton International Airport.

In 1976…in Thornton…a 13 year old boy riding a bicycle was struck and killed by lightning.

In 2000…lightning struck three homes in central Arapahoe County east of Denver.  Damage was estimated at 47 thousand dollars.

In 2003…hail to 1 inch in diameter pelted Denver.  Hail to 7/8 inch was measured in Boulder.

In 2008…heavy rain also caused flash flooding over south Denver and its nearby suburbs. Heavy rain…from 2.5 to 4 inches…fell in less than 90 minutes.  Firefighters rescued 20 people as the water quickly rose along creeks…flooded roadways…and stranded motorists.  Three people had to be rescued along Cherry Creek when the bike path flooded.  In Evergreen…a man suffered minor injuries when he was struck by lightning.  It entered his finger…traveled down his body… And exited his foot.

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.

9-10

In 2006…mid and high cloudiness overnight on both days resulted in two temperature records.  The low temperature of 71 degrees on the 9th was a record high minimum for the date.  The low temperature of 68 degrees on the 10th equaled the record high minimum for the date first set in 1936.

10

In 1924…0.01 inch of rain fell over downtown Denver.  This along with the 0.01 inch of rainfall on the 4th was the only rainfall of the month…making this the driest August on record in the city.

In 1962…the high temperature reached 100 degrees at Stapleton Airport.

In 1970…hail stones to 1 inch in diameter were reported in the Fort Lupton  area.

In 1972…dry thunderstorm microburst winds gusting to 46 mph briefly reduced the surface visibility to 3/4 mile in blowing dust at Stapleton International Airport.

In 1978…lightning struck two men in Aurora…killing one and injuring the other.

In 1982…a tornado was sighted near Castle Rock and remained on the ground for 10 minutes.  Wind gusts to 60 mph were reported in Castle Rock.  No damage was reported.

In 1994…heavy thunderstorm rains caused flash flooding on Lena Gulch in west metro Denver.  Damage was estimated at 50 thousand dollars.  Lightning struck a house in Westminster…causing a small attic fire.

In 1996…strong thunderstorm winds toppled a tent at a company picnic in Westminster.  Five people received minor injuries when the tent collapsed.  Two cars nearby were also damaged by flying debris.  A weak tornado (f0)…first sighted near Denver International Airport…traveled east to near Bennett and Strasburg.  No significant damage was reported.

In 1998…heavy rain caused flooding and flash flooding problems over southwest metro Denver.  An observer in Lakewood measured 3.26 inches of rainfall in an hour. Several streets were flooded in central Lakewood.  In addition…a trailer park along Lena Gulch in Wheat Ridge was evacuated due to high waters.  One inch diameter hail fell near Roggen.

In 1999…thunderstorm-producing tornadoes…damaging straight line winds…heavy rain…and hail hammered metro Denver.  In the city…small hail and heavy rainfall…up to 2.50 inches an hour…caused a 20-foot by 50-foot section of the roof to collapse at a furniture warehouse.  Damage to the warehouse was estimated at 1 million dollars.  Heavy rain also flooded several underpasses with up to 3 feet of water…which resulted in a number of stalled vehicles.  In Fort Lupton…a tornado bounced across the area.  Spotty damage was reported along a 5-mile path as trees…power poles…and lines were downed.  In addition…an empty semi-trailer was overturned onto another vehicle northeast of the town.  Thunderstorm winds gusted to 81 mph south of Fort Lupton.

In 2004…severe thunderstorms pummeled metro Denver with large hail.  Hail up to 3 inches in diameter was measured 10 miles east of Castle Rock.  Two inch diameter hail fell in Louisville…10 miles north of Hudson…and 1 mile east of Brighton.  Hail to 1.75 inches was reported in Englewood… 1 mile south of Ft. Lupton…and 8 miles east of Boulder. Hail to 1.50 inches was reported around Boulder…near Broomfield…and in Lafayette…Thornton and Greenwood Village. Hail from 3/4 to 1 inch in diameter was found in Broomfield… Brighton…Castle Rock…Denver and Thornton…and near Longmont… Northglenn…Greenwood Village…Morrison…and Wheat Ridge. Severe thunderstorm wind gusts were recorded to 66 mph in Parker and to 60 mph 5 miles northeast of Boulder.  There were no damage estimates from the hail or wind.

11

In 1872…fog was very dense until about 8:00 am.  There was water dripping from the roofs of houses as if it had rained. The rain gage showed 0.01 inch of moisture…even though there had been no rainfall.

In 1927…an apparent dry microburst produced only a trace of rain and brief northwest winds sustained to 34 mph with gusts to 44 mph.

In 1980…hail up to golf ball size caused some roof and car damage in the southern part of Aurora.

In 1990…lightning ignited a storage tank filled with 10 thousand gallons of crude oil in a farmer’s field near Dacono…25 miles north of Denver.  Flames shot to 40 feet high for nearly 2 hours before being extinguished.  A lightning bolt also struck 21 miles north of Denver at an Erie fire station…causing extensive damage to the gas meter and electrical system.  The sudden power surge blew out the station’s television set…a refrigerator…and a pop machine.  Small fires spread throughout the structure… Totally destroying the building’s electrical wiring.  The fires were quickly extinguished by the in-resident fire fighters.  Golf ball size hail was reported in Denver near the intersection of Santa Fe Drive and I-25.

In 1992…dime size hail fell in Westminster.

In 1994…strong thunderstorms produced large hail across northwest and north metro Denver.  One inch diameter hail fell in Brighton with 3/4 inch hail reported in Westminster and at Indian Hills in the foothills west of Denver. Lightning struck a house in Arvada.  The resulting fire destroyed one-third of the house.  Funnel clouds were sighted over Westminster.

In 1997…large hail…strong winds…and torrential rains hammered portions of Lakewood and south Denver.  Nearly 1 inch of rain fell in the span of 10 minutes in south Denver with a storm total of 1.81 inches.  Street flooding was extensive as gutters and other drainage systems in the area were clogged by hail…piled several inches deep…and other debris.  Strong thunderstorm winds to 50 mph and large hail accompanied by heavy rain caused extensive damage to cars…homes…and businesses.  Several trees were downed by the strong winds…and trees were stripped of their leaves by hail.  A water lily exhibition on display at the Denver Botanic Gardens was heavily damaged.  Final estimates of the damage included 60 million dollars to automobiles and an additional 68 million dollars to homes and businesses.  Hail to 1 1/2 inches in diameter fell in south Denver with 3/4 to 1 inch hail in Lakewood.  A man received minor injuries in Aurora when he was struck by lightning while talking on the telephone.

In 2003…hail to 3/4 inch in diameter was measured in Aurora near Cherry Creek.

In 2012…a severe thunderstorm produced a wind gust to 60 mph at Rocky Mountain Metropolitan Airport.

Continue reading August 8 to August 14: This week in Denver weather history →

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

This Week in Denver Weather History

August isn’t normally associated with severe weather but our look back at the history books show it certainly can and does happen.  We see many occurrences of dangerous lightning and of particular note is the flood events – a byproduct of the monsoon season the first of August brings.

18-2

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

1

In 1888…heavy rain in the mountains and foothills caused flooding on clear creek in Golden.  The high waters also washed away portions of the railroad tracks in the canyon between Idaho Springs and Golden.

In 1901…the temperature reached a high of 100 degrees in the city.

In 1902…the high temperature climbed to 100 degrees in downtown Denver.

In 1914…a thunderstorm produced 1.00 inch of rainfall in just 21 minutes and north winds sustained at 43 mph with gusts to 50 mph.  Rainfall totaled 1.17 inches.

In 1938…the temperature climbed to a high of 100 degrees in downtown Denver…which is the record maximum for the date.  The temperature was also recorded on this date in previous years.

In 1976…flight operations at Stapleton International Airport were suspended for 90 minutes when the airport tower radar was knocked out and water reached a foot deep on some taxi ramps after 1.50 inches of rain fell in one hour.  Heavy rain also caused minor flooding in east Denver and Aurora where lightning damaged the roof of a home and injured the owner.  One young man was swept down a flooded ditch…but was rescued by firemen.  A number of rafts were floated in flooded streets.  Thunderstorm rainfall totaled 1.71 inches at Stapleton International Airport.

In 1978…a tornado damaged a house and broke a power pole 5 miles northwest of Parker.  A microburst wind gust to 52 mph briefly reduced visibility to 1 mile in blowing dust at Stapleton International Airport.

In 1985…heavy thunderstorms roared through the southern and western sections of metro Denver…producing large hail and heavy rain.  Lightning hit a recreational vehicle trailer causing it to burn.  There was a lot of street flooding over western suburbs where rainfall totaled over 2 inches in some areas.  One inch diameter hail was reported in Littleton and near Evergreen.  Hail piled 4 to 6 inches deep at Tinytown in the foothills southwest of Denver.

In 1990…a small rope-like tornado was spotted in open country 15 miles southeast of centennial airport. No damage was reported from the twister.

In 1992…pilots reported a funnel cloud near the construction site of the new Denver International Airport.  A few minutes later…a tornado was reported near Bennett.  The tornado remained on the ground for about 18 minutes and was visible from the national weather service office at Stapleton International Airport.  Thunderstorm wind gusts to 70 mph were reported near Bennett and Watkins with a wind gust to 60 mph at Brighton.  Two men were injured when struck by lightning.  A young man sustained serious injuries when struck by lightning while jet skiing on Cheery Creek Reservoir.  A man received only minor injuries when struck by lightning while golfing in Westminster.

In 1994…heavy thunderstorm rains in the foothills west of Denver caused the closure of the Virginia Canyon Road north of Idaho Springs by rocks and debris.

In 2001…a 34 year old man on the South Platte River bike path in Denver received minor injuries when lightning struck a nearby tree.  Lightning…coupled with strong thunderstorm winds…knocked out electrical power to about 10 thousand homes and businesses in Golden.

In 2006…strong thunderstorms hit southern metro Denver. A severe thunderstorm wind gust estimated to 71 mph knocked down a tree in Aurora near Cherry Creek. Lightning sparked a fire in a home near Lone Tree and struck a transformer at an RTD light rail station at Interstate 25 and Yosemite street.  Heavy thunderstorm rainfall forced the closure of Arapahoe road between Holly and Quebec streets due to high water.  Flooding was also reported near park meadows mall and greenwood village.  Heavy rainfall also caused flooding in Highlands Ranch…Lone Tree…and Parker.  Water up to 6 inches deep was reportedly running over the roads.

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 1 to August 7: This week in Denver weather history →

August 2020 top shots: Monthly photo slideshow

Sunflowers at sunset near DIA. (Jessica Fey)
Sunflowers at sunset near DIA. (Jessica Fey)

As the calendar turns to August, the summertime heat begins to fade and that makes it easier to get out and enjoy all of the outdoor activities Colorado has to offer.  From a walk in a park to afternoon thunderstorms to an abundance of wildlife, photo opportunities abound as is seen in our slideshow.

Our monsoon season typically arrives about now and that means better chances for moisture.  However with limited instability, the intensity of storms are more sedate.  That doesn’t mean however that the weather is any less photographic.

  • Slideshow updated August 27, 2020

By the end of the month some of our seasonal feathered friends will be looking to leave the state giving our last chance to see them till spring.  Larger mammals are gearing up for the rut (mating season) and that can make for some intense scenes.

Showcasing images captured by ThorntonWeather.com readers as well as some of our own, our monthly slideshow covers the entire gamut of weather and nature related imagery. Sunsets, sunrises, wildlife and of course every type of weather condition are vividly depicted.

To learn more about how to send your photo to us for inclusion in the slideshow, see below the slideshow.

[flickr_set id=”72157715425013148″]

What is missing in the slideshow above?  Your photo!

Our monthly photo slideshow is going to feature images that we have taken but more importantly images that you have captured.  The photos can be of anything even remotely weather-related.

Landscapes, current conditions, wildlife, pets, kids.  Whimsical, newsy, artsy.  Taken at the zoo, some other area attraction, a local park, a national park or your backyard.  You name it, we want to see and share it!

Images can be taken in Thornton, Denver or anywhere across the extraordinary Centennial State.  We’ll even take some from out of state if we can tie it to Colorado somehow.

We’ll keep the criteria very open to interpretation with just about any image eligible to be shown in our slideshows.

What do you win for having your image in our slideshow?  We are just a ‘mom and pop’ outfit and make no money from our site so we really don’t have the means to provide prizes.  However you will have our undying gratitude and the satisfaction that your images are shared on the most popular website in Thornton.

To share you images with us and get them included in the slideshow just email them to us or share them with ThorntonWeather.com on any of the various social media outlets.  Links are provided below.

So come on, get those camera’s rolling!

August 2019 weather recap: Thornton experiences very warm, very dry month

The month of August usually brings respectable amounts of precipitation and by the latter part of the month, cooler temperatures. Mother Nature however had other plans last month keeping the heat on and the moisture at bay.

A dry, westerly flow was dominant for much of the month. While there were a few cool fronts and PM thunderstorms, these failed to amount to much at all and were a rarity.

Thornton saw 21 days of 90 degree or higher readings during the month. Only five days saw precipitation and three of those were in virtually negligible amounts.

Thornton’s overall average temperature for the month was 73.9 degrees. This makes it the warmest August since ThorntonWeather.com came online 13 years ago. The reading was a good ways above the long-term Denver average for the month of 72.5 degrees.

At DIA, where Denver’s official temperatures are recorded, it was even warmer with an average of 75.4 degrees. This put August 2019 into the books tying August 2007 as the warmest August ever recorded in the Mile High City.

One temperature record was set in Denver during the month when on the 19th, the high temperature topped out at 99 degrees. This topped the old record high for the date of 97 degrees.

In terms of precipitation, Denver averages 1.69 inches during the month of August. This year, Thornton recorded a paltry 0.18 inch during the month. Denver fared a bit better with 0.58 inches. Both were clearly far short of average and Thornton’s was the least amount of precipitation received in August since ThorntonWeather.com came online 13 years ago.

Click here to view Thornton’s August 2019 climate report.

Thornton, Colorado's August 2019 temperature summary. (ThorntonWeather.com)
Thornton, Colorado’s August 2019 temperature summary. (ThorntonWeather.com)
Thornton, Colorado's August 2019 precipitation summary. (ThorntonWeather.com)
Thornton, Colorado’s August 2019 precipitation summary. (ThorntonWeather.com)
Thornton, Colorado's August 2019 weather summary. (ThorntonWeather.com)
Thornton, Colorado’s August 2019 weather summary. (ThorntonWeather.com)
CLIMATE REPORT
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
910 AM MDT SUN SEP 1 2019

...................................

...THE DENVER CO CLIMATE SUMMARY FOR THE MONTH OF AUGUST 2019...

CLIMATE NORMAL PERIOD 1981 TO 2010
CLIMATE RECORD PERIOD 1872 TO 2019

WEATHER         OBSERVED          NORMAL  DEPART  LAST YEAR`S
                 VALUE   DATE(S)  VALUE   FROM    VALUE  DATE(S)
                                          NORMAL
................................................................
TEMPERATURE (F)
RECORD
 HIGH             105   08/08/1878
 LOW               40   08/26/1910
                        08/25/1910
                        08/24/1910

HIGHEST            99   08/19
LOWEST             51   08/28

AVG. MAXIMUM     90.5              87.2     3.3     86.8
AVG. MINIMUM     60.2              57.9     2.3     58.0
MEAN             75.4              72.5     2.9     72.4
DAYS MAX >= 90     18              11.5     6.5       11
DAYS MAX <= 32      0               0.0     0.0        0
DAYS MIN <= 32      0               0.0     0.0        0
DAYS MIN <= 0 0 0.0 0.0 0 
PRECIPITATION (INCHES)
 RECORD MAXIMUM 5.85 1979
 MINIMUM 0.02 1924 
TOTALS 0.58 1.69 -1.11 0.93 
DAILY AVG. 0.02 0.05 -0.03 0.03 
DAYS >= .01         3               8.6    -5.6        7
DAYS >= .10         1               4.3    -3.3        2
DAYS >= .50         0               1.2    -1.2        0
DAYS >= 1.00        0               0.3    -0.3        0
GREATEST
 24 HR. TOTAL    0.46   08/08 TO 08/08           08/14 TO 08/14

SNOWFALL (INCHES)
TOTALS            0.0               0.0

DEGREE_DAYS
HEATING TOTAL       0                10     -10        9
 SINCE 7/1          0                16     -16        9
COOLING TOTAL     326               244      82      247
 SINCE 1/1        757               688      69      862

FREEZE DATES
RECORD
 EARLIEST     09/08/1962
 LATEST       06/08/2007
EARLIEST                        10/07
LATEST                          05/05
.................................................................

WIND (MPH)
AVERAGE WIND SPEED              9.3
RESULTANT WIND SPEED/DIRECTION   2/155
HIGHEST WIND SPEED/DIRECTION    40/020    DATE  08/20
HIGHEST GUST SPEED/DIRECTION    56/020    DATE  08/20

SKY COVER
POSSIBLE SUNSHINE (PERCENT)   MM
AVERAGE SKY COVER           0.50
NUMBER OF DAYS FAIR            9
NUMBER OF DAYS PC             21
NUMBER OF DAYS CLOUDY          1

AVERAGE RH (PERCENT)     50

-  INDICATES NEGATIVE NUMBERS.
R  INDICATES RECORD WAS SET OR TIED.
MM INDICATES DATA IS MISSING.
T  INDICATES TRACE AMOUNT.

Thornton’s August 2019 preview: Temperatures begin to cool, fewer storms intrude

As summer vacations wind down and families prepare to send their kids back to school in August, Colorado weather also starts to settle down. The chances for severe weather decrease markedly during August and by the end of the month daytime temperatures are dropping quite a bit as well.

Find out more about what lies ahead with Thornton’s August weather here.

August 2018 weather recap: Month sees cooler than normal temps, well below normal precipitation

Somewhat of a mixed bag for Thornton’s weather in August.  While we enjoyed temperatures near normal without too many extremes, precipitation was lacking considerably from what we expect during the month.

The month started out toward the cool side but with days of above normal temps interspersed.  For the first few weeks it appeared we would end up a good bit cooler than normal but then the heat returned for much of the last week driving up average temperatures.

Precipitation was quite disappointing with only a couple decent rainfalls during the month and a few minimal events.

Probably the most notable thing for the month was the relatively persistent haze from smoke from wildfires to our west.  While it made for pretty sunrises and sunsets, it obscured our normally beautiful blue skies.

Thornton finished the month with an average temperature of 70.4 degrees.  That is more than two degrees cooler than Denver’s long term August average of 72.5 degrees. As is the norm, Denver’s official measurement came in a good bit warmer with an average of 72.4 degrees.

Our highs ranged from a maximum of 94.9 degrees on the 4th of the month down to a low of 47 degrees on the morning of the 20th.  Denver matched our maximum on the same date and saw a low of 46 degrees on the 20th which also tied the record low for the date.

The month saw a paltry 0.52 inches fall in Thornton’s rain bucket.  Denver actually fared better with 0.93 inches.  Both measurements however fell short of the August average of 1.69 inches.

Click here to view Thornton’s August 2018 climate report.

Thornton, Colorado's August 2018 temperature summary. (ThorntonWeather.com)
Thornton, Colorado’s August 2018 temperature summary. (ThorntonWeather.com)
Thornton, Colorado's August 2018 precipitation summary. (ThorntonWeather.com)
Thornton, Colorado’s August 2018 precipitation summary. (ThorntonWeather.com)
CLIMATE REPORT
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
318 PM MDT SAT SEP 1 2018

...................................

...THE DENVER CO CLIMATE SUMMARY FOR THE MONTH OF AUGUST 2018...

CLIMATE NORMAL PERIOD 1981 TO 2010
CLIMATE RECORD PERIOD 1872 TO 2018

WEATHER         OBSERVED          NORMAL  DEPART  LAST YEAR`S
                 VALUE   DATE(S)  VALUE   FROM    VALUE  DATE(S)
                                          NORMAL
................................................................
TEMPERATURE (F)
RECORD
 HIGH             105   08/08/1878
 LOW               40   08/26/1910
                        08/25/1910
                        08/24/1910
                        08/22/1904
HIGHEST            95   08/04       105     -10       95  08/19
LOWEST             46   08/20        40       6       51  08/04
AVG. MAXIMUM     86.8              87.2    -0.4     85.7
AVG. MINIMUM     58.0              57.9     0.1     57.3
MEAN             72.4              72.5    -0.1     71.5
DAYS MAX >= 90     11              11.5    -0.5       10
DAYS MAX <= 32      0               0.0     0.0        0
DAYS MIN <= 32      0               0.0     0.0        0
DAYS MIN <= 0       0               0.0     0.0        0

PRECIPITATION (INCHES)
RECORD
 MAXIMUM         5.85   1979
 MINIMUM         0.02   1924
TOTALS           0.93              1.69   -0.76     1.86
DAILY AVG.       0.03              0.05   -0.02     0.06
DAYS >= .01         7               8.6    -1.6        6
DAYS >= .10         2               4.3    -2.3        4
DAYS >= .50         0               1.2    -1.2        2
DAYS >= 1.00        0               0.3    -0.3        0

GREATEST
 24 HR. TOTAL    0.38   08/14 TO 08/14

SNOWFALL (INCHES)
 TOTAL            0.0
RECORD
 TOTAL            0.0               0.0

DEGREE_DAYS
HEATING TOTAL       9                10      -1        8
 SINCE 7/1          9                16      -7        8
COOLING TOTAL     247               244       3      216
 SINCE 1/1        862               688     174      749

FREEZE DATES
RECORD
 EARLIEST     09/08/1962
 LATEST       06/08/2007
EARLIEST                        10/07
LATEST                          05/05
.................................................................

WIND (MPH)
AVERAGE WIND SPEED              10.3
RESULTANT WIND SPEED/DIRECTION   3/176
HIGHEST WIND SPEED/DIRECTION    41/280    DATE  08/27
HIGHEST GUST SPEED/DIRECTION    60/270    DATE  08/27

SKY COVER
POSSIBLE SUNSHINE (PERCENT)   MM
AVERAGE SKY COVER           0.50
NUMBER OF DAYS FAIR           12
NUMBER OF DAYS PC             17
NUMBER OF DAYS CLOUDY          2

AVERAGE RH (PERCENT)     48

WEATHER CONDITIONS. NUMBER OF DAYS WITH
THUNDERSTORMS             9   MIXED PRECIP           0
HEAVY RAIN                1   MODERATE RAIN          3
LIGHT RAIN               12   FREEZING RAIN          0
LT FREEZING RAIN          0   HAIL                   0
HEAVY SNOW                0   SNOW                   0
LIGHT SNOW                0   FOG W/VIS <=1/4 MILE   2
FOG                       4   HAZE                   8

-  INDICATES NEGATIVE NUMBERS.
R  INDICATES RECORD WAS SET OR TIED.
MM INDICATES DATA IS MISSING.
T  INDICATES TRACE AMOUNT.

August 26 to September 1: This week in Denver weather history

This week in Denver weather history
August 26 to September 1: This week in Denver weather history

Significant events on Denver’s weather history calendar get a bit less numerous as we enter what is historically a relatively quiet period of the year. That isn’t to say however that major weather events can’t occur. Our look back at this week in Denver weather history includes a massive hail storm in 1944, many events in which lightning injured people and the warmest temperature ever recorded in September.

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.

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.

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.

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 Continue reading August 26 to September 1: This week in Denver weather history →

August 19 to August 25: This week in Denver weather history

This week in Denver weather history
August 19 to August 25: This week in Denver weather history

Funnel clouds, tornadoes, deadly flooding and more highlight our look back at this week in Denver weather history.

From the National Weather Service:

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.

18-19

In 1875…nearly 0.75 inch of rainfall in the city overnight… Possibly assisted by heavier rainfall upstream…produced a decided and rapid rise in Cherry Creek…which washed out some bridges. Other small creeks and streams were filled to overflowing.

19

In 1983…heavy rain fell across the northern metro Denver suburbs with 1.50 to 1.80 inches of rain in Broomfield… Arvada…and Thornton.

In 1989…lightning killed a 31-year-old man and injured his 10 year old nephew when it hit a tree they were walking under in the foothills about 5 miles west of Boulder. The boy received mouth to mouth resuscitation on the scene and recovered after being hospitalized overnight. Three other people were knocked to the ground by the bolt…but were uninjured.

In 1990…3/4 inch diameter hail was reported in Wheat Ridge. A thunderstorm over west Denver dumped an inch of rain in 20 minutes…causing minor street flooding. One inch diameter hail was reported over east Denver. Ping pong to golf ball size hail was reported 14 miles northeast of Denver at the intersection of 122nd Ave. and Brighton Blvd. The hail stones knocked out windows and did an unspecified amount of damage to the roof of a house. Close by…heavy thunderstorm rains caused gullies…irrigation ditches…and small streams to overflow their banks near the intersection of 120th Avenue and Riverdale Road. Flood waters 1 to 2 feet deep covered the river bottom land along the South Platte River. However…no structures were threatened by the flood waters.

In 1999…heavy rain…up to 5 inches in two hours…caused east tollgate creek to jump its banks. The bike path adjacent to the creek was underwater at several locations. Several underpasses were also flooded…halting traffic. In addition…an unfinished playground at a local elementary school was completely flooded. Lightning struck a vehicle at east Evans Avenue and Tower Road. The woman inside the vehicle was not injured.

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.

Continue reading August 19 to August 25: This week in Denver weather history →

August 12 to August 18: This week in Denver weather history

This week in Denver weather history
August 12 to August 18: This week in Denver weather history

Denver’s weather calms considerably in August as compared to many other months but the history books show plenty of notable events in our past. Lightning, flooding rain and even a tornado highlight this week in Denver weather history.

8-13

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

12

In 1876…the temperature climbed to a high of 100 degrees in downtown Denver.

In 1941…excessive thunderstorm rainfall flooded streets and delayed traffic for a few hours in some sections of the city. The basements of a considerable number of homes and commercial buildings were flooded. The total value of the damage was unknown. Only 0.94 inch of thunderstorm rainfall was recorded downtown.

In 1969…a man and a 9-year old boy were injured…when lightning struck a tree near where they were standing. Both were revived after treatment…but the boy later died of respiratory failure due to electrical shock.

In 1984…heavy thunderstorm rains drenched southern metro Denver. Rural roads in Douglas County received minor washouts. Hail…as large as 3/4 inch in diameter…was reported in southeast Aurora with one inch diameter hail reported near Parker. Rainfall totaled 1.00 inch at Stapleton International Airport.
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.

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.

15

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.

In 2013…a dry microburst uprooted 30 to 40 large trees across a 12-block area of the Park Hill neighborhood in east central Denver. Several trees were snapped near the base along with numerous branches…8 to 10 inches in diameter. Power poles and lines were also downed with resulted in outages which affected seven hundred residents. One of the downed trees crushed a car`s hood… narrowly missing the driver. At Denver International Airport…a peak wind gust of 22 mph was observed from the southwest.

Continue reading August 12 to August 18: This week in Denver weather history →