Thornton, Colorado, USA
UpdatedTue, 12-Dec-2017 2:25pm MST 


ThorntonWeather.com on Twitter

ThorntonWeather.com on Facebook


Weather Geek Stuff - weathergeekstuff.com

Rocky Mountain Weather Network

Tony's Takes Photography


Recent News and Posts

Sierra Leone: At Least 200 Dead After Mudslide, Flooding

Monday, August 14th, 2017 11:47am MST

Officials in Sierra Leone’s capital, Freetown, say more than 200 people are dead after a mudslide and heavy flooding. The catastrophe in the early hours of Monday followed hours of heavy rains. Witnesses described a hillside collapse in the Regent area and said roads became “churning rivers of mud.” Sinneh Kamara, a technician at the Connaught… » Click here to read the rest of Sierra Leone: At Least 200 Dead After Mudslide, Flooding

Join the Discussion - Post your commentJoin the Discussion!

NOAA Upgrades Hurricane Season To Above Normal

Monday, August 14th, 2017 5:46am MST

Less than half way through the 2017 hurricane season the National Oceanic and Atmospheric Administration has upgraded the chances of an above-normal season in the Atlantic. In May, NOAA had estimated that the chance of an above-normal season was about 45 percent. Now the chance of an above-normal season is set at about 60 percent. This… » Click here to read the rest of NOAA Upgrades Hurricane Season To Above Normal

Join the Discussion - Post your commentJoin the Discussion!

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

Monday, August 14th, 2017 5:00am MST
This Week In Denver Weather History

August 13 to August 19: 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:


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


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.


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 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.


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 1902…a thunderstorm produced west winds sustained to 48 mph with gusts to 60 mph…but only a trace of rain.

In 1952…a thunderstorm wind gust to 50 mph was recorded at Stapleton Airport.

In 1960…lightning struck a warehouse in central Denver… Causing 8 thousand dollars in damage to the building and stored electrical equipment.

In 1975…large hail…1 1/2 to 1 3/4 inches in diameter…fell about 4 miles north of Castle Rock. Hail caused some minor damage in Aurora. A funnel cloud was reported 25 miles east of Denver near Bennett.

In 1981…a tornado touched down briefly in open country just to the east of Aurora. No damage was reported.

In 1982…a thunderstorm wind gust to 61 mph was recorded at Buckley Field in Aurora. At the same time almost an inch of rain flooded and closed streets in south Aurora. A women was hit by lightning just north of Denver. A house in the area was also struck.

In 1985…a thunderstorm produced strong wind gusts over southern metro Denver. One strong wind gust hit Cheery Creek Reservoir…capsizing a boat and drowning a man. The wind gusts…clocked as high as 50 mph…also downed a few trees.

In 1989…1 3/4 inch diameter hail fell at Intercanyon in the foothills of Jefferson County.

In 1990…lightning caused minor damage to a south Aurora home. No injuries were reported.

In 1994…strong thunderstorm winds caused damage in southern weld County near Hudson and Fort Lupton. Two mobile homes were destroyed and a few lost their roofs. Up to 20 downed power poles and the destruction of two 115 thousand-volt towers caused widespread power outages. Thunderstorm gust front winds from the north gusted to 48 mph at Stapleton International Airport.

In 2000…lightning ripped most of the roof from a home in southeast Aurora. The bolt sparked a fire which destroyed the residence. Damage was estimated at 250 thousand dollars.

In 2002…the temperature climbed to a maximum of 100 degrees setting a new record high for the date.

In 2003…a teenager was injured when he was struck by lightning while camping at Herman Lake…13 miles northwest of Georgetown. The boy was knocked unconscious and suffered minor injuries.

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.

» Click here to read the rest of August 13 to August 19: This week in Denver weather history

Join the Discussion - Post your commentJoin the Discussion!

Seasonal temperatures, slight chance for storms start Thornton’s workweek

Monday, August 14th, 2017 4:56am MST

A day with pretty typical weather for this time of year. Temperatures should be right near average and we see just a slight chance for PM thunderstorms.

The day starts with mostly sunny skies and those will be with us into the early afternoon when coverage will increase some. After sunrise temperatures will begin a steady climb toward an afternoon high of 88 degrees. The afternoon and evening will bring some isolated thunderstorm activity.

Overnight tonight look for lows near the 60 degree mark.

Join the Discussion - Post your commentJoin the Discussion!

Thornton’s weekend offers comfortable temps, daily chances for thunderstorms

Friday, August 11th, 2017 4:55am MST

Not any major changes in our recent weather expected for this weekend. Temperatures will remain below normal and there will be some thunderstorm activity each afternoon and evening.

For Friday, following some fog in a few spots we will see partly sunny skies above. Temperatures will top out right around the 80 degree mark. The afternoon and evening should see some isolated thunderstorm activity. Overnight lows will be near 60 degrees.

Saturday will offer up the most sun of the three day period, at least for the morning. Temperatures will climb to the low to mid-80s. Some thunderstorms will be possible in the afternoon and evening. Low temperatures overnight Saturday into Sunday morning will again dip to around 60 degrees.

For Sunday, we’ll see a few more clouds with highs in the low 80s. Again, the afternoon and evening offer up some thunderstorms, possibly the best chances of the weekend.

All in all it looks to be a pretty decent late summer weekend. Enjoy!

Join the Discussion - Post your commentJoin the Discussion!

A bit cooler, better chances for storms on Thursday

Thursday, August 10th, 2017 5:10am MST

Mother Nature looks to mix things up again today. Instability courtesy of a disturbance coupled with a cold front will cool things a bit and offer up varying chances for showers throughout the day.

We start out with a good bit of cloud cover then should see some of a break in coverage as we head toward mid-day. Clouds will then increase in the afternoon and evening. Temperatures today will be topping out in the mid to upper 70s, a good ways below the average for the date of 88 degrees.

The morning hours may bring a sprinkle of rain here and there but nothing that should amount to much. This afternoon however, as daytime heating helps unsettle things, the opportunity for storms increases. Some brief, heavy rain will be possible along with gusty winds.

Some severe storms will be possible, most likely to our southwest, but the skies will bear close watching nevertheless.

Join the Discussion - Post your commentJoin the Discussion!

Wednesday continues trend toward warmer, drier conditions

Wednesday, August 9th, 2017 5:06am MST

It is taking some time but we gradually shaking off the cool, damp weather of much of the past week. Today brings some sun, warmer temps and less of a chance for storms.

We start out under partly sunny skies and will see that continue until at least the afternoon when some increased cloud coverage can be expected. Temperatures will climb steadily toward a high in the mid to upper 70s, warmer but still well below normal (89 degrees).

The morning will stay dry then this afternoon and evening do offer up some chances for storms, primarily driven by daytime heating. Best opportunity will come between about 3:00 and 6:00pm.

Overnight tonight lows will dip to the mid to upper 50s.

Join the Discussion - Post your commentJoin the Discussion!

Thornton’s Tuesday warms up a bit, still sees chances for showers

Tuesday, August 8th, 2017 5:12am MST

While the overall pattern will be warmer and drier today, that doesn’t necessarily mean we are done with the wet stuff. There still remains a good chance for activity, particularly in the late afternoon and evening.

We start out the day with mostly cloudy skies and while there may be an occasional patch of sun, overall the sky will be well covered today. Temperatures will be warmer today with highs in the low to mid-70s.

A few sprinkles of rain will be possible by mid to late morning then in the afternoon chances for activity increase and will last until midnight or so. Overnight lows will dip to the mid to upper 50s tonight. You can keep an eye out for those showers here.

Join the Discussion - Post your commentJoin the Discussion!

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

Monday, August 7th, 2017 5:03am MST
This Week In Denver Weather History

August 6 to August 12: 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:


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 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 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.

In 2013…heavy rain caused localized flash flooding in Aurora. An undergound parking garage at an apartment complex was inundated with 3 to 4 feet of water. Flash flooding forced a road closure at East Mississippi Ave. and Alton St. Also… several people had to be rescued when three vehicles stalled in floodwaters at Alameda Ave. and Havana St. The stationary thunderstorms dumped 2.75 inches of rain in less than 45 minutes. In addition…large hail…up to one inch in diameter… was reported north of Roxbourough State Park. At Denver International Airport…just a trace of rainfall was observed.


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.

» Click here to read the rest of August 6 to August 12: This week in Denver weather history

Join the Discussion - Post your commentJoin the Discussion!

Cool, damp weather conditions start off Thornton’s workweek

Monday, August 7th, 2017 4:58am MST

An almost fall-like day ahead for us. We will be under a steady cover of clouds with periods of drizzle, rain and thunderstorms being possible and temperatures well below normal.

The day starts with cloudy skies and you can expect similar coverage throughout. High temperatures today will only be in the mid to upper 60s offering one of our coolest days since May.

This morning some periods of rain will be possible then this afternoon and evening bring our best chance for precipitation coupled with perhaps some thunder.

Looking ahead at the balance of your week, you can expect temperatures to remain below normal with varying degrees of precipitation possible. Get a look at the extended forecast here.

Join the Discussion - Post your commentJoin the Discussion!