Thursday sees the heat return to Thornton

After two days of below average temperatures, we climb well-above again today. The heat will continue through the weekend with no chances for precipitation foreseen.

Skies will be sunny today but with areas of smoke from wildfires to the northwest. High temperatures will climb to the mid-90s. One thing that may inhibit highs is the aforementioned smoke. While the smoke is not good, it may help us out on those highs.

Tonight, skies remain mostly clear with smoke continuing. Lows will dip to the mid-60s.

Looking ahead, the weekend looks to be a toasty one with highs of 100 degrees currently expect Saturday and Sunday. It will remain dry but as with today, smoke may cool us slightly below those forecasted numbers.

Denver breaks record low temperature for August 5

Record Cold Temperatures

Did you feel a very slight chill in the air this morning? It was very pleasantly cool and in fact, record-tying.

As measured at Denver International Airport, the city’s official low temperature dipped to 47 degrees. This breaks the record low for the date set in 1978.

Amusingly enough, the record low follows record-setting heat. Just two days ago, Denver set a record high temperature.

Here in Thornton, we weren’t quite as cool with a low of 50 degrees. That was our coldest August 5th reading in the past 20 years that Thornton Weather has been operating. The previous low for the date was 53.9 degrees in 2015.

Editor’s note: This story originally reported Denver’s low as 48 degrees, per the National Weather Service. They then revised the number to 47 degrees and the story was updated accordingly.

Thornton’s August 2026 preview: Temps begin to cool, severe weather eases

Thornton's August Weather Preview
Thornton’s August Weather Preview

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.

Denver sets high temperature record for August 3

Record High Temperature

The heat has been on throughout the summer and continued today as Denver set another record high.

As measured at Denver International Airport, the Mile High City’s official high temperature today came in at 102 degrees. That breaks the old record high for the date of 100 degrees set in 1878.

Here in Thornton, we bested Denver slightly with a high of 103 degrees.

August 2 to August 8: This week in Denver weather history

This Week in Denver Weather History

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

From the National Weather Service:

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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.

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In 1876…grasshoppers were in great abundance in the city and caused considerable damage to gardens and to crops in the surrounding farms and ranches.

In 1951…heavy thunderstorms rumbled across metro Denver through the night. Heavy rain totaled 3.45 inches at Stapleton Airport. This was the greatest 24 hour precipitation ever recorded during the month of august in Denver.

In 2007…heavy rain caused localized flash flooding near Ft. Lupton. Up to 8 inches of water was reported across County road 18. In addition…several other County roads in the immediate area were washed out.

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In 1878…the high temperature climbed to 100 degrees in downtown Denver.

In 1900…a thunderstorm produced west winds sustained to 48 mph with gusts to 55 mph…but only a trace of rain.

In 1903…a thunderstorm produced a trace of rainfall and northwest winds sustained to 45 mph with gusts to 60 mph. The high temperature was 99 degrees.

In 1927…a thunderstorm produced hail and sustained north winds to 22 mph.

In 1933…heavy cloudburst rains caused the failure of the Castlewood dam…which resulted in flash flooding on Cherry Creek…the deaths of 7 people in Denver…and flood damage estimated at 1 million dollars. Lower Denver was flooded during the morning by waters pouring down Cherry Creek and its valley from Castlewood Dam…which had broken between midnight and 2:00 am. Heavy rain of 3 to 9 inches in 9 hours in the watershed above the dam resulted in the failure. At 7:30 am…the flow in Cherry Creek was reported at 16 thousand second-feet as compared with a peak flow of 3 thousand second-feet in other years. The flood waters ruined hundreds of acres of crops and drowned scores of farm animals. Six bridges in Denver were swept away. Great deposits of mud were left in the lower sections of the city…including hundreds of basements and lower floors of buildings. At the end of the month…a deadly stench still rose from swampy areas near the lower city limits.

In 1963…heavy thunderstorm rains in the Parker area caused Cherry Creek to overflow…which damaged roads.

In 1985…a tornado touched down briefly about 10 miles northeast of Parker. No damage was reported.

In 1991…upslope northeast winds produced chilly temperature readings and heavy rain across metro Denver. Rainfall… With no thunder…totaled 1.56 inches at Stapleton International Airport where the heavy rain briefly reduced the surface visibility to 7/8 mile. The mercury climbed to a high of only 63 degrees.

In 1992…a thunderstorm wind gust to 64 mph was recorded in Brighton. A wind gust to 60 mph was measured near the construction site of the new Denver International Airport. Lightning started a fire in an Evergreen church…causing over 75 thousand dollars in damage.

In 1998…3/4 inch hail fell in Jefferson County 15 miles northwest of Arvada.

In 2006…heavy thunderstorm rainfall caused flash flooding along Leyden Creek in unincorporated Jefferson County. An automated rain gauge on upper Leyden Creek…6 miles northwest of Arvada…measured 2.68 inches of rainfall in less than 2 hours. Two to three feet of water covered the roadway at the intersection of 82nd and Quaker Street.

In 2009…a woman riding her bike… In training for an ironman triathlon…was struck by lightning in Boulder. She was in the 78th mile of a 100-mile training ride when she was hit. The woman lost her vision initially and couldn`t move her arms. After a short stay in the hospital…she made of complete recovery.

In 2013…severe wet microburst thunderstorms produced damaging winds and very heavy rain in and around Buckley Air Force Base…Erie and Lafayette. Peak gusts included: 68 mph in Erie…61 mph at Buckley AFB… And 60 mph in Broomfield…4 miles east-southeast of Erie and Lafayette. In Erie…a velodrome under construction was heavily damaged by heavy rain and high winds. The wind toppled the eastern third of the 250-meter cycling track. Bolts measuring one-half-inch thick by 7 1/2 inches in length were ripped out of concrete footers while 16-inch-wide trusses…collapsed under the force of the wind. In town…heavy rain… Around 2.5 inches in less than one hour…caused extensive street flooding. The intense wind also downed trees which resulted in localized power outages. In addition…an empty semi-trailer was blown on its side. A weak non supercell tornado touched down briefly in an open field…7 miles northwest of Hudson. The storm forced seven incoming flights at Denver International Airport to be diverted and contributed to 45-minute delays for others. At Denver International Airport…a peak wind gust of 55 mph was observed from the northeast…with 0.66 inches of rainfall recorded. The very heavy rain produced flash flooding in part of Aurora. Road closures were set up in both directions on both Picadilly Road and Gun Club Road…just north of Buckley AFB. A man had to be rescued when his car was trapped in flood waters at the intersection of 6th Ave. and Picadilly Road. Flash flooding was also observed at the junction of e-470 and I-70 with water running over the road.

In 2018…a gust front associated with a dissipating thunderstorm moved out of the foothills of Boulder and northern Jefferson counties continued to push eastward into Denver. The storm knocked down trees and branches. Power lines were also damaged which produced scattered outages. Peak wind gusts included: 67 mph near Gold Hill…64 mph in south Boulder…62 mph at Rocky Mountain Metropolitan Airport…and 60 mph at Denver International Airport.

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In 1988…two inches of rain fell in 3 hours at both Morrison and Wheat Ridge. Thunderstorm rainfall totaled 0.80 inch overnight at Stapleton International Airport.

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

Denver sets record high minimum for July 27

Record High Temperature

Following on a record setting high, the nighttime brought little relief and set another warm weather record.

As measured at Denver International Airport, the Mile High City’s low temperature for July 27 was only 74 degrees. This breaks the previous record high minimum for the date of 72 degrees set in 1931.

Notably, this reading is also the third warmest minimum temperature ever recorded in Denver. The warmest is 77 degrees recorded on July 3, 1881.

Here in Thornton, we did not stay near as warm at night with a low of 64.2 degrees.

Denver sets high temperature record for July 26

Record High Temperature

No rest from the summer heat for the Mile High City as Denver sets a record high for the second day in a row.

As measured at Denver International Airport, the Mile High City’s official high temperature today came in at 103 degrees. That breaks the old record high for the date of 100 degrees set in 1910.

Here in Thornton, we bested Denver slightly with a high of 104 degrees.

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

This Week in Denver Weather History

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

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In 2008…a streak of 26 consecutive days of 90 degrees shattered the previous record of 18 consecutive days established in 1901 and 1874.   Ironically…no new single day record high temperatures were set in the month of July. In August however…a record of 104 degrees was set on the 1st…and another record of 103 degrees was set on the 2nd. In addition…a record low min of 70 degrees was set on August 2nd.

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.

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In 1891…a thunderstorm produced sustained northeast winds to 44 mph with gusts to 60 mph and 0.16 inch of rain.

In 1894…a thunderstorm produced sustained southwest winds to 36 mph with gusts to 58 mph…but only 0.04 inch of rain.

In 1910…the high temperature reached 100 degrees in downtown Denver.

In 1959…a Denver man was stunned while standing by a car that was struck by lightning.  He was treated for burns and shock at a local hospital.  Thunderstorm winds gusted to 55 mph at Stapleton Airport.

In 1983…two heavy thunderstorms hit the northern and western suburbs.  The first drenched Northglenn with an inch of rain in 30 minutes.  The second storm dumped an inch or more of rain in Idaho Springs and Evergreen.  The heaviest rainfall… 2.90 inches in an hour…caused minor street flooding in Golden.

In 1984…heavy early morning thunderstorms drenched the foothills southwest of Denver.  Rainfall to 1 1/2 inches in just 30 minutes occurred between Evergreen and Conifer.  In nearby turkey creek canyon…1.80 inches of rain was recorded in 35 minutes.

In 1985…a long rope-like white tornado touched down 5 miles east of Erie and stayed on the ground…mainly over an open field…for 18 minutes.  However…the twister damaged a few cars on I-25 and injured 3 people from broken glass.  The storm flipped over a van…blew out car windows…and ripped a highway sign.  It also blew an outbuilding off its foundation.  A tornado also touched down briefly 8 miles north of Bennett.  No damage was reported from this storm.

In 1988…a 9-year-old girl was slightly injured by lightning in Parker.

In 2003…a severe thunderstorm in and south of Franktown produced hail as large as 1.75 inches in diameter.

In 2022…severe thunderstorms produced strong winds across portions of Arapahoe and Boulder counties. The gusts ranged from 60 to 70 mph…with hail up to 1 inch in diameter near Aurora and Cherry Creek. The wind knocked down some large tree limbs…and the hail caused minor property damage.

26-27

In 1885…heavy cloudbursts on the palmer divide south of Denver caused flooding on Cherry Creek in the city overnight.  The high water washed away street and railroad bridges and a few houses.  The flood waters completely inundated the rail yards in lower downtown.  This was the worst flood on Cherry Creek since May 19-20…1864…but the damage was mitigated by stream improvements and fewer structures near the channel.  There was also no simultaneous flood on the South Platte River to slow the flow of water through the city.  Rainfall in the city was only 0.08 inch on the 26th.

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In 1897…an apparent dry microburst produced sustained west winds to 48 mph with gusts to 60 mph and a trace of rain.

In 1901…a thunderstorm produced north winds to 38 mph with gusts to 41 mph and rainfall of only 0.01 inch in downtown Denver.  This was the only measurable rainfall of the month… Making this the driest July on record.

In 1953…an unconfirmed tornado in south Lakewood touched down briefly and abruptly dissipated.  No damage was reported from the twister.

In 1955…the public sighted a funnel cloud estimated at 500 feet above the ground near the western edge of Lowry Field. Wind estimates up to 60 mph were reported in the vicinity.

In 1956…a severe thunderstorm produced 3/4 inch diameter hail and wind gusts to 48 mph at Stapleton Airport where rain fall totaled 1.08 inches.

In 1965…a tornado was sighted 21 miles south of Denver in Douglas County.  No damage was reported.

In 1977…a thunderstorm wind gust to 51 mph was recorded at Stapleton International Airport.  A funnel cloud was sighted by an aircraft east of Parker.

In 1982…heavy rain doused Boulder with 1 1/2 to 3 inches of rain over a short period of time…causing extensive street flooding.

In 1984…strong thunderstorms drenched several areas. Rainfall of 1.04 inches occurred in just 20 minutes at Boulder.  Downpours also hit Aurora and northeast Denver… Delaying flights at Stapleton International Airport for an hour.  Up to 3/4 inch of rain fell in central Aurora in 15 minutes.

In 1989…lightning hit a home in Littleton…setting a bed on fire.  Damage was confined to the bedroom.

In 1994…lightning struck a furniture store in Boulder… Igniting a fire which caused major damage to the building and contents.

In 1997…lightning sparked a fire…causing extensive damage to a home in Watkins.  Heavy rain caused Lena Gulch to surge 2 feet over its banks in Golden.  The fire department had to rescue a man when his van stalled in high waters. High waters from swollen creeks and streams washed out bridges and several sections of road in southeast Aurora. A 200-to-300 foot section of road was washed away where Picadilly Street dips across coal creek.  Three youths had to be rescued when they became stranded by rapidly rising water in another normally dry creek bed.

In 1999…lightning was suspected of igniting a fire which caused substantial damage to a farm in Hudson.  The blaze destroyed a 10-foot by 60-foot metal pole barn…a pick-up truck…a SUV…a boat and trailer…3 four wheeler vehicles… And other farm equipment.

In 2007…a man was struck and killed by lightning while jogging at Matthews Winters Park in Morrison.

In 2022…severe thunderstorm produced strong winds near Chatfield Reservoir and Parker…with gusts up to 66 mph. Hail up to 1 inch in diameter was reported at Gold Hill and near Highlands Ranch.

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In 1956…96 percent of the total precipitation for the month of July occurred over the last five days of the month. Heavy thunderstorms produced 4.00 inches of rainfall at Stapleton Airport.  This amount of precipitation in 5 days or less had been exceeded only 3 times in previous record. The last time had been in December of 1913 as snow. Considerable property damage occurred across metro Denver from flooding.

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

Out of Office Taking a Break

Out of the Office and in the Mountains
Time for some much-needed R & R that does not involve a keyboard and computer screen!

We’ll be largely incommunicado in our website news section and on social media for the next couple of weeks but rest-assured we shall return.

In the meantime, our website will continue to be updated with live conditions, radar, statistics and of course the forecast. See you soon!

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