Thornton, Colorado, USA
UpdatedSun, 15-Sep-2019 6:00pm MDT 


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Thornton’s workweek starts off a bit cooler with good chance for thunderstorms

Monday, June 17th, 2019 5:12am MDT

A somewhat typical day of weather for this time of year. We will enjoy mild temperatures but will be seeing some afternoon and evening thunderstorms for excitement.

The day starts with some areas of fog and then we will be seeing partly sunny skies for the rest of the morning. Cloud cover will increase by late morning / early afternoon as storms start to build.

From noon-onward to sunset will bring our best chances for storms. Some storms could turn severe with large hail, damaging wind and brief, heavy rain. You will certainly want to keep an eye on the sky.

In terms of temperatures, look for highs in the mid to upper 70s.

Tonight, a few lingering storms may roll through under mostly sunny skies. Look for lows tonight in the low to mid-50s.

Our Severe Weather Briefing Page is your one-stop shop to keep an eye on any weather drama.

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Thornton’s weekend weather to offer temps near normal, good chances for storms

Friday, June 14th, 2019 4:54am MDT

A series of weather disturbances are going to be moving through northeastern Colorado serving to destabilize conditions for the three day period. Temperatures will remain mild but showers and thunderstorms will be becoming likely.

Friday will be the warmest day of the period with highs in the mid-80s. Mostly sunny skies will be above with an increase in cloud cover this afternoon. The afternoon brings a chance for storm activity, primarily from about 3:00pm to 6:00pm. Tonight, thunderstorm activity should end around sunset. Overnight lows will be in the mid-50s.

Saturday cools down a bit with highs in the mid-70s. Partly cloudy skies will be above with just a bit of a chance of a morning sprinkle. Showers should become more widespread in the afternoon. Saturday night into Sunday morning, partly cloudy skies will be above with lows in the low 50s.

Mostly sunny skies will be above on Sunday morning with an increase in cloud cover in the afternoon. Highs will be in the mid to upper 70s. Thunderstorms and showers will be likely after noon and into the evening.

Have a fantastic weekend!

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Temps bounce up Thursday, slight chance for PM thunderstorms

Thursday, June 13th, 2019 4:56am MDT

After a brief cooling off yesterday, we warm back up today with mercury readings a bit above normal. There will also be a bit of a chance for some thunderstorm activity in the afternoon and evening.

The day starts with mostly sunny skies and similar sky conditions will remain into the afternoon. Temperatures today will top out in the mid-80s, a bit above the average high for the date of 82 degrees.

We do see just a slight chance for thunderstorms after 2:00pm and lasting until midnight.

Tonight, partly cloudy skies will be above with overnight lows in the mid-50s.

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June 9 to June 15: This Week in Denver Weather History

Wednesday, June 12th, 2019 5:58am MDT
This week in Denver weather history

June 9 to June 15: This Week in Denver Weather History

June means severe weather in Colorado and our look back at this week showcases that fact. Numerous, historical events have occurred during this week in the past including the disastrous Hayman fire and the infamous 1988 Denver tornadoes.

From the National Weather Service:


In 1979…rain…at times with thunder on the 7th…fell almost continuously through the morning of the 9th. Rainfall totaled 2.28 inches at Stapleton International Airport over the 3 days. High temperature of only 49 degrees on the 8th was a record low maximum for the date.


In 1900…an apparent cold front produced north winds to 42 mph with gusts to 47 mph.

In 1923…heavy rainfall totaled 2.18 inches in downtown Denver…where northwest winds were sustained to 27 mph. Heavy rain also fell in Boulder…causing flooding on Boulder and south Boulder creeks.

In 1939…post-frontal sustained northwest winds to 35 mph produced some blowing dust…which reduced the visibility to one mile at times during the afternoon. Dusty conditions prevailed into the early evening. The airport station reported a maximum wind of 56 mph. A few minor injuries and some damage resulted. A few trees were uprooted…some fruit was blown from trees…and a section of power lines was blown down.

In 1959…dry thunderstorm winds…estimated to near 70 mph… Toppled a 40-foot-high poplar tree…which was 4 to 5 inches in diameter…near Cherry Creek dam. The Colorado state patrol reported a possible tornado 1 mile south of the dam.

In 1960…strong gusty winds tore the roofs from 2 patios in Aurora. One of the roofs was blown over a house and landed on a car damaging its top. A house trailer was also overturned. Other minor damage was reported to roofs… Windows…and trees in Aurora. A thunderstorm wind gust to 43 mph was recorded at Stapleton Airport.

In 1963…golf ball size hail fell at Cheery Creek Reservoir.

In 1967…a small tornado damaged trees and a dwelling in south Denver. The storm touched down at the intersection of 1st Avenue and Harrison Street and moved northeast to the intersection of 3rd Avenue and Albion Street. Damage included 3 small roofs removed…15-20 large trees uprooted…one car overturned and thrown against a house… Plus other minor damage. A funnel cloud reported at the same time 10 miles north of Denver possibly touched ground. Later…funnel clouds were reported 12 miles south-southeast of Stapleton International Airport…10 miles southwest…and 5 miles north. A tornado was sighted 3 1/2 miles east of Stapleton International Airport by weather bureau personnel for a duration of 5 minutes. Heavy rain and some hail fell over much of the area.

In 1974…the start of the shortest seasonal snow free period on record…94 days…occurred with the last snow of the season…a trace…on the 8th. The first snow of the next season occurred on September 11th when a trace of snow fell at Stapleton International Airport. A funnel cloud was observed just east of Aurora and a small funnel was sighted just northeast of Stapleton International Airport.

In 1985…a thunderstorm wind gust to 62 mph was reported at Golden Gate Canyon in the foothills west of Denver.

In 1986…a thunderstorm…which dumped heavy rain and caused some street flooding across north metro Denver…produced a small tornado 5 miles east of Brighton. No damage was reported.

In 1987…strong thunderstorm wind gusts in Conifer destroyed a porch on a house; the wind gust apparently picked up the porch and dropped it on a man…killing him. The wind also damaged the roof of the house and a nearby barn. The same thunderstorm spawned a tornado…which touched down briefly just south of Lakewood. No damage was reported. Up to 3 inches of rain fell in a short time 8 miles southwest of Littleton. A few businesses in Englewood suffered minor water damage. A tornado was sighted between Watkins and Bennett. It was on the ground for 15 minutes. A weak tornado also touched down 4 miles southwest of Castle Rock. The twister tossed an aluminum shed into the air and carried it about 100 feet. A funnel cloud was sighted 15 miles east-northeast of Stapleton International Airport.

In 1988…golf ball size hail fell in Conifer along with 1.30 inches of rain. Three miles north of Louisville…1.10 inches of rain fell in 20 minutes. Ping pong ball size hail was measured in Arvada.

In 1990…3/4 inch hail fell in Castle Rock.

In 1991…hail two inches in diameter fell near Evergreen. Hail to 1 inch diameter fell in Lakewood where a funnel cloud was also sighted. One inch diameter hail was also reported in Aurora.

In 2002…high temperatures…low relative humidities…and strong gusty winds allowed the Hayman wildfire…located in the foothills to the southwest of Denver…to become the largest wildfire in the state’s history. Although the fire was initially started by a U.S. Forest Service employee…the ongoing drought and dry conditions allowed the fire to spread rapidly out of control. The wildfire consumed nearly 138 thousand acres of forest land and 133 homes before it could be contained and finally extinguished on June 30th. About 1800 households had to be evacuated during the blaze. Southwest winds aloft swept the smoke plume directly over metro Denver…creating poor air quality and blocking the sun. Much of metro Denver choked on smoke with the southern suburbs receiving the most. Smoke and ash restricted surface visibilities to a mile or less at times in the Denver and Castle Rock areas and to 2 miles at Denver International Airport.

In 2003…thunderstorm winds gusted to 51 mph at Denver International Airport. The storm produced only a trace of rain.

In 2004…severe thunderstorms produced large hail across portions of metro Denver for the second day in a row. The most extensive damage occurred across southern sections of metro Denver in Aurora…Lakewood…Littleton…and south Denver. The combined damage to homes and vehicles…not including commercial buildings…was estimated at 146.5 million dollars…making the event the 4th costliest insurance disaster in the state’s history. Hail as large as 2 1/4 inches in diameter fell near southern Aurora with hail to 1 3/4 inches in the city of Denver and in Lakewood. Hail to 1 1/2 inches fell near Morrison with 1 inch hail measured in Thornton…near Buckley Air Force Base…and near Roggen. Hail to 3/4 inch diameter fell in Littleton and near Conifer. A small tornado touched down near Bennett…but did no damage.


In 1864…high water from melting snow combined with heavy rains over the upper reaches of the South Platte River forced the river over its banks and caused flooding of low lying areas along the river in the city. The amount of rainfall in the mountains and in the city is unknown.


In 1943…a man was killed by lightning while using a surveying instrument at Buckley Field.

In 1969…hail stones 2 to 3 inches in diameter caused extensive damage to buildings and automobiles in an area from northeast of Boulder to Longmont. Two funnel clouds were reported near Castle Rock. A funnel cloud and 1 inch hail stones were reported 10 to 20 miles southeast of Stapleton International Airport. Hail stones to 1 3/4 inches fell 3 miles west of Littleton. Hail to 3/4 inch diameter fell over southeast Denver.

In 1988…thunderstorm winds clocked to 60 mph unroofed a porch and downed a fence at a home near Stapleton International Airport. A small tornado touched down briefly in northeast Aurora. Another small tornado touched down for 3 minutes in southeast Aurora. No damage was reported from either twister.

In 1989…a National Weather Service observer saw lightning strike 2 storage tanks at 40th and Havana…3/8 mile northeast of Stapleton International Airport. The strike temporarily knocked out some weather observing equipment at the National Weather Service.

In 1991…a tornado was sighted 2 miles south of Castle Rock. No damage was reported. The funnel cloud associated with the tornado was sighted for 5 minutes by national weather service observers at Stapleton International Airport.

In 1994…lightning struck a home in Denver…which started a fire in the attic and caused minor damage.

In 1997…lightning struck a security guard at the castle pines golf course near Castle Rock. He received only minor injuries.

In 1999…severe thunderstorms rolled off the foothills over metro Denver…producing large hail and damaging winds. Hail to 1 inch diameter fell near Evergreen with 1 3/4 inch hail measured west of Golden. Hail to 1 1/2 inches fell in Commerce City with one inch hail in Lakewood…Wheat Ridge… The city of Denver and at Denver International Airport where thunderstorm winds gusted to 58 mph. As the storms moved east…3/4 inch hail was reported in Aurora…and damaging thunderstorm winds developed between Bennett and Strasburg. Winds gusting as high as 69 mph blew half a metal roof from a shed in a Bennett lumberyard. A small barn was also leveled between Bennett and Strasburg. Winds also gusted to 58 mph near Manilla.

In 2000…a dry microburst produced a wind gust to 58 mph at Jefferson County Airport. Thunderstorm winds gusted to 55 mph at Denver International Airport.

In 2003…hail as large as 1 3/4 inches was measured at Centennial Airport and near Parker.

In 2005…hail to 7/8 inch in diameter was reported near Parker with 3/4 inch hail measured near Castle Rock.

In 2009…lightning struck an apartment complex…a veterinary hospital in Boulder and caused minor damage. Lightning also struck two oil tanks…one in Boulder and the other at Front Range airport north of Watkins. The oil tanks in both instances were set on fire and suffered extensive damage.

In 2010…a complex of severe thunderstorms hammered portions of eastern Arapahoe…eastern Douglas and western Elbert counties. The hail ranged from 1 inch to 3 inches in diameter. The largest hail was observed near Elizabeth. Areas in and around Aurora…byers…Parker and Thornton were also impacted by large hail. One weak tornado touched down near prospect valley but did no damage. At Denver International Airport…a peak wind gust to 35 mph was observed from the northwest.


In 1882…heavy thunderstorm rains on the morning of the 10th caused a rapid rise in Dry Creek…which enters the South Platte River at Fairview in present day south Denver. This…combined with additional heavy rainfall on the 11th caused the South Platte River to overflow. Five people drowned and several houses were destroyed. Total losses in the city and suburbs was estimated at 75 thousand dollars. Total rainfall in central Denver was 2.21 inches over the 2 days.

In 2013…the high temperature of 99 degrees on the 10th broke the previous record maximum temperature of 97 for the date. Also…the minimum temperature of 68 and high temperature of 100 degrees on the 11th established a new record for highest minimum and maximum temperature for the date.

» Click here to read the rest of June 9 to June 15: This Week in Denver Weather History

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Wednesday to offer slightly cooler temperatures, slight chance for showers

Wednesday, June 12th, 2019 5:13am MDT

Cooler, stable air has settled in for the day on the Front Range. That will serve to keep temps below normal and allow just a chance for an evening shower.

A few clouds start us off but then we will see those ease leading to mostly sunny skies for most of the day. Highs today will top out in the mid-70s.

This evening brings a slight chance for a shower after about 6:00pm. Tonight, shower activity should end by 11:00pm or so and then we will have partly cloudy skies above.

Lows will drop to around 50 degrees.

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Seasonal temperatures, calm conditions for Thornton’s Tuesday

Tuesday, June 11th, 2019 5:24am MDT

A nice looking day ahead for us. Temperatures will be near normal and while there will be a few clouds, they won’t be overly intrusive.

Mostly sunny skies will be above throughout the day with the mid to late afternoon seeing an increase in cloud coverage.

Highs will top out right around the 80 degree mark. Late afternoon and evening will bring some breezy winds but no thunderstorms.

Tonight, mostly cloudy skies will be above with lows around 50 degrees.

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Thornton’s workweek starts off with calm conditions, temps a bit cooler than normal

Monday, June 10th, 2019 4:58am MDT

If you felt like there was a bit of a chill this morning you would be right as #Thornton dipped to 41 degrees in the pre-dawn hours. We will turn that around though and see a mild day but with temps a bit below normal.

Sunny skies start us off and will be with us till the early afternoon when a few clouds will arrive. We do not expect to see any thunderstorm activity in our area today. High temperatures will top out around 77 degrees, about 5 degrees shy of normal for the date.

Tonight, partly cloudy skies will be above with lows around 50 degrees.

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Thornton’s weekend starts warm with some storms, will end a good bit cooler

Friday, June 7th, 2019 5:25am MDT

Somewhat of a mixed bag of weather for the three day period. Temperatures will be above normal with the usual chance of storms Friday and Saturday. However, a cold front late Saturday will cool things down considerably for Sunday.

For today, mostly sunny skies start us off then the afternoon brings an increase in cloud cover. Highs today will be in the mid-80s. Scattered thunderstorms will roll off the mountains after noon with some having a slight chance to turn severe so this will warrant close watch. Tonight, any storms should end soon after sunset, skies will clear and lows will be in the mid-50s.

Saturday will offer a healthy dose of sun with clear skies much of the day. Highs will top out around the 80 degree mark with some breezy winds. There will be just a slight chance for a PM thunderstorms. Saturday night into Sunday, clouds increase and lows will dip to around 50 degrees.

Sunday will be coolest day of the period with highs only in the mid-60s. Partly clear skies will be above with a chance for PM showers and thunderstorms.

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Temps a bit above normal, dry conditions for Thornton’s Thursday

Thursday, June 6th, 2019 4:57am MDT

A very nice looking day ahead for us. We’ll enjoy lots of sun, mild temperatures and should avoid any showers.

Sunny skies start things off to be followed by just a few clouds in the afternoon. Temperatures will top out in the low 80s. Right now it looks like any thunderstorm activity will stay to our south.

Tonight, mostly clear skies will be above with lows in the mid-50s.

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Wednesday to offer temps right near normal, good chance for thunderstorms

Wednesday, June 5th, 2019 5:00am MDT

A largely typical, late spring day for Thornton. Highs today will be right near normal for the date and the afternoon and evening look to bring showers and thunderstorms.

Sunny to mostly sunny skies will be with us this morning. Cloud cover will then increase in the afternoon as storms approach.

Best chance for storm activity will come from about 2:00pm to 8:00pm. Some gusty wind and possibly heavy rain may be seen with some of the storm cells.

High temperatures today will top out right near the average high for the date of 79 degrees.

Tonight, thunderstorm activity will end by midnight then cloud cover will ease. Overnight lows will be in the low to mid-50s.

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