Thornton, Colorado, USA
UpdatedTue, 22-Sep-2020 1:25pm MDT 


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Thornton’s workweek starts off unseasonably warm, gives just a slight chance for storms

Monday, July 6th, 2020 5:15am MDT

Well, if you don’t like the heat, then you won’t be happy with today’s weather. In fact, you likely will be less than pleased with the entire week’s forecast.

For today, sunny skies start us off and will be with us through the morning. The afternoon brings a few clouds and just the slightest chance for a thunderstorm after 2:00pm. As the temperatures, look for a high today in the mid-90s, a good bit above the average high for the date of 89 degrees.

Tonight, any storms will end before sunset then skies will clear. Overnight lows will be in the low to mid-60s.

Looking ahead, today may actually end up being one of the “coolest” days of the week. Mercury readings in the mid to upper 90s are expected through the weekend. More here.

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Unseasonably warm temperatures, decent chances for thunderstorms for Thornton’s Independence Day weekend

Friday, July 3rd, 2020 4:12am MDT

A pretty good looking holiday weekend ahead for us however, there will be no break from the heat. We do however have a good chance for some thunderstorms each day.

For Friday, sunny skies start us off followed by an increase in clouds later this morning and into the early afternoon. Highs today will top out in the mid-90s. The afternoon brings a chance for some thunderstorms with the best opportunity coming from about 3:00pm to 6:00pm. Any storm activity should end by 9:00pm and then we will have partly clear skies overnight lows. Low temperatures tonight will dip to the low 60s.

Independence Day brings more of the same. Mostly sunny skies will be above for the most part. Highs will reach the low 90s. The afternoon brings a pretty good chance to see some thunderstorm activity. Saturday evening storm activity should again end by about 9:00pm. Overnight lows into Sunday morning will dip to around 60 degrees under partly clear skies.

Sunday looks much like the previous two days. Sunny skies start us off with some clouds in the afternoon. Highs will be in the low to mid-90s. Some scattered PM showers and thunderstorms will be seen. Have a safe and fun holiday weekend and God bless the USA!

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Thornton’s July weather preview: Temperatures climb, PM storms are common

Friday, July 3rd, 2020 3:19am MDT


Change is of course the one constant in Denver’s weather but come July, things actually get pretty consistent.

The standard formula for a day in July is a sunny morning, clouds developing in the late morning and early afternoon. Come mid-afternoon, thunderstorms are rolling off of the foothills and into the metro area and the eastern plains. These storms do occasionally reach severe status containing hail, gusty winds and heavy downpours of rain.

Check out our July weather preview for a complete look at what is in store for the month ahead.

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June 28 to July 4: This week in Denver weather history

Thursday, July 2nd, 2020 4:13am MDT

This Week in Denver Weather History

As always, an interesting week in Denver and Thornton weather history.  Various severe weather items are noteworthy, none more so than on July 2, 2006 when a teenager wearing an iPod was struck with lightning.  The music player actually contributed to the teen’s injuries by providing a direct route for the electricity into the victim’s head via the headphones.

From the National Weather Service:


In 2002…the maximum temperature in Denver equaled or exceeded 90 degrees for 13 consecutive days…equaling the 5th longest such streak on record.  The record of 18 consecutive days was set during the summer of 1901.


In 1873…there was a great deal of smoke over the city from forest fires in the mountains.

In 1875…smoke from forest fires in the foothills south of Denver were visible from the city.

In 1913…an apparent dry microburst produced southwest winds sustained to 44 mph with gusts to 48 mph in the city.

In 1925…a thunderstorm produced north winds sustained to 38 mph with gusts to 44 mph.

In 1958…a microburst caused a brief wind gust to 58 mph at Stapleton Airport.

In 1964…lightning struck several homes in metro Denver… Sparking fires.  Some flooding occurred in the stockyards area…at West 45th Avenue and St. Paul Street…and along Harvard Gulch.

In 1997…strong microburst winds of unknown speed downed several trees…signs…and at least one light pole in the Fort Lupton area.  Two trees knocked over by the storm downed power lines causing scattered outages.

In 2002…a thunderstorm wind gust to 60 mph was recorded in Parker.

In 2005…severe thunderstorms produced wind gusts to 66 mph near Longmont and to 60 mph near Niwot.  No damage was reported.  A thunderstorm produced a wind gust to 55 mph at Denver International Airport during the afternoon.

In 2015…a lightning strike injured 15 hikers as they were descending 500 feet below the summit of Mt Bierstadt…in Clear Creek County…south of Georgetown. Eight adults were were transported from the trailhead…and three of those were taken to Denver-area hospitals. One was in serious condition…the other two had non-life threatening injuries. The strike also killed a dog. Severe thunderstorms produced hail up to 1 1/2 inches in diameter…7 miles southwest of Byers…and 1 1/4 inches in diameter…13 miles north of Elizabeth.

In 2016…severe thunderstorms produced hail…from quarter to ping ball size…over northwest…west and southwest parts of Denver. In addition hail up to quarter size was also reported just southeast of Denver International Airport. Officially only a trace of rainfall was measured at the airport…with a peak wind gust of 35 mph from the west.


In 1874…eight different fires in mountain forests were visible from the city.  All of the fires were extensive… And the volume of smoke from each was immense.  Three of these fires had been burning from the 18th with varied intensity.

In 1911…an apparent dry microburst produced sustained winds to 45 mph.

In 1960…a strong gust of wind blew a small foreign sedan off the highway near Brighton…injuring the driver.  East winds gusted to 40 mph at Stapleton Airport.

In 1961…thunderstorm winds estimated as high as 40 to 50 mph occurred over southeast Denver.  No significant damage was reported.

In 1962…heavy rain and small hail caused some flooding in southwest Denver.

In 1995…upslope cloudiness with rain and fog cooled temperatures to record levels.  Low temperature of 47 degrees equaled the record for the date.  High temperature of only 54 degrees set a new record low maximum for the date.  Rainfall totaled 0.90 inch at Denver International Airport and 0.41 inch at the site of the former Stapleton International Airport.

In 2003…a severe thunderstorm in Parker produced hail to 1 inch in diameter.

In 2011…two airmen from the Colorado National Guard suffered minor injuries when they were struck by lightning. They were hit while on duty at a flight line at Buckley Air Force Base. At Denver International Airport…a microburst produced a peak wind gust to 72 mph.


In 1990…almost a year to date after the record breaking heat in early July 1989…the third longest heat wave in Denver history started.  From June 29th through July 2nd the temperature reached 100 degrees or more on four consecutive days.  The highest reading of 102 degrees occurred on the 29th…30th…and 1st.  Combined with the 102 degree reading on June 27th this would have been the longest heat wave on record…but the temperature climbed to only 98 degrees on June 28th.


In 2000…the 29th marked the beginning of a near record hot streak for metro Denver.  The high temperatures…as recorded at Denver International Airport…exceeded the 90 degree mark for 17 consecutive days from June 29th through July 15th. This was one day short of equaling the all time record.  The record of 18 consecutive 90 degree or above days was first set from July 1st through July 18th…1874.  The record was equaled from July 6th through July 23rd…1901.


In 1879…dense smoke from mountain forest fires covered the city and obscured the sun as it set behind the mountains.

In 1900…a thunderstorm produced northwest winds to 44 mph with gusts to 58 mph…but only a trace of rain.

In 1917…north winds were sustained to 47 mph with gusts to 52 mph.

In 1942…a strong thunderstorm produced hail and heavy rainfall in south Denver.  Leaves were stripped from trees and heavy rain caused street flooding which halted traffic.  Hail of unknown size reached a depth of 9 inches on the ground.

In 1965…funnel clouds were observed to the south of Stapleton International Airport and in Jefferson County…15 miles southwest of the airport.  Later…a tornado touched down briefly 1 mile east of Littleton…causing only minor damage. Another tornado was observed 12 miles southwest of Stapleton International Airport in Jefferson County.  Hail to 3/4 inch in diameter fell in the bear valley area…12 miles south- southwest of Stapleton International Airport.  Yet another tornado was sighted 10 miles northwest of the airport. Cloudbursts accompanied by hail battered areas of Arapahoe and Adams counties east of Denver…damaging ripening grain fields.  At Lafayette…3.50 inches of rain fell in 30 minutes…causing some flooding.

In 1982…numerous funnel clouds were observed over southwest metro Denver.  Only one funnel touched down near the intersection of Jewell and Kipling.  The tornado was on the ground for about 5 minutes and caused no damage except for uprooting some trees.  In addition…thunderstorms produced heavy rain and hail in the foothills west of Denver.  Over an inch of rain fell in a short time near Idaho Springs… Causing clear creek to overflow its banks and flood a few low lying areas of the town.  A few people were evacuated… And water and mud entered several stores.  The heavy rain also washed out several roads.  Hail piled up to a depth of 3 to 4 inches near Idaho Springs.   Hail to 3/4 inch was reported at many places across metro Denver including Stapleton International Airport.  Lightning struck a chemistry building on the university of Colorado campus in Boulder and started a small fire.  Thunderstorm wind gusts to 60 mph were reported near Brighton.

In 1984…heavy rain caused some street and basement flooding in Littleton.  One location received 1.56 inches of rain in 75 minutes.

In 1987…a weak tornado near Watkins stayed on the ground for 5 minutes.

In 1990…a small twister touched down in an open field just north of the rocky mountain arsenal.  No damage was reported.

In 1998…hail as large as 1 inch in diameter fell near Evergreen.

In 2005…a severe thunderstorm produced hail as large as 3/4 inch near Roggen.  The hail destroyed a wheat field.

In 2006…the temperature reached a high of 98 degrees at Denver International Airport.  This marked the 19th day in June with a maximum temperature of 90 degrees or more setting a new all-time record for the month.

In 2011…very strong thunderstorm winds were also observed across portions of the urban corridor. A peak wind gust to 65 mph was recorded…2 miles northeast of boulder with a gust to 63 mph at Front Range Airport at Watkins and 7 miles southeast of Denver International Airport.  The peak wind gust measured at Denver International Airport itself was 45 mph.  A severe thunderstorm also produced one inch in diameter hail 2 miles south-southeast of Parker. In addition…a lightning strike destroyed a home in north Denver.


In 1873…heavy rainfall overnight totaled 1.42 inches. Mountain peaks to the southwest of the city were covered with fresh snow on the morning of the 1st.

» Click here to read the rest of June 28 to July 4: This week in Denver weather history

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Thornton’s weekend starts off a bit cooler, will end with a return to the heat

Friday, June 26th, 2020 4:53am MDT

We get a one day reprieve from the unseasonably warm temperatures of the recent past today. That does not last long though and the mercury will be climbing for the latter part of the weekend.

For today, partly sunny skies will be above throughout the day with some breezy winds. Highs today will top out in the mid-80s. The afternoon brings a chance for thunderstorms, particularly from about 3:00pm to 8:00pm. Strong winds, possibly hail will be seen. Overnight tonight, skies will be clearing and lows dropping to the upper 50s.

Saturday brings sunny skies in the morning then the usual clouds in the afternoon. Highs will return to the low 90s. The afternoon will bring a chance for thunderstorms. Saturday night into Sunday morning, partly cloudy skies will be above with lows in the upper 50s.

Sunday will bring our warmest day of the period. Highs will reach the mid-90s under mostly sunny skies.

Have a great weekend!

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June 2020 top shots: Monthly photo slideshow

Thursday, June 25th, 2020 9:11pm MDT
A pelican takes off at Barr Lake State Park at sunrise. (Bill Hutchinson)

A pelican takes off at Barr Lake State Park at sunrise. (Bill Hutchinson)

The month of June typically sees springtime severe weather reach its height of activity in northeastern Colorado.

This affords the opportunity to capture extraordinary images of amazing weather phenomena from monstrous supercell thunderstorms to heavy rain, hail and even tornadoes.

  • Slideshow updated June 24, 2020

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.  June brings some very dynamic weather and the photos are a great way to see the stunning variety.

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

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!

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Thornton’s Thursday brings more hot temps, slight chance for thunderstorms

Thursday, June 25th, 2020 4:54am MDT

Today’s weather looks to be much like we saw yesterday. Mercury readings will be well above normal and we stand just a bit of a chance for a thunderstorm.

The day starts off with sunny skies then by late morning / early afternoon some cloud cover begins to develop. High temperatures will again reach the low to mid-90s. After 1:00pm and until about 11:00pm some scattered thunderstorms will develop. As before, coverage is not supposed to be particularly great and strong winds will be the biggest threat.

Tonight, partly cloudy skies will be above and overnight lows dip to around 60 degrees.

A cold front arrives tonight as well that will cool us down tomorrow and bring a better chance for showers Friday. We then heat right back up for the weekend. Get a look in the extended weather forecast here.

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June 21 to June 27: This week in Denver weather history

Wednesday, June 24th, 2020 5:10am MDT

This Week in Denver Weather History

A typical week during the spring and summer for Denver – tornadoes, hail, damaging winds and more.


In 2012…it was the hottest June in Denver since weather records began back in 1872. The average temperature for the month was 75.0 degrees which was 7.6 degrees above normal. There were a total of seventeen 90 degree days in the month of June. The highlight of record setting month was a stretch of five consecutive 100 degree days from the 22nd to the 26th. This was only the third time in Denver weather history in which this happened. Two of the high temperatures during the stretch peaked at 105 degrees… Which set the all-time record for the month of June and tied the all-time maximum temperature for Denver.


In 1875…smoke from several large forest fires in the mountains was visible from the city on each of these days.


In 1897…high winds raked the city overnight. Southeast winds were sustained to 60 mph with gusts as high as 72 mph on the 20th. Southeast winds were sustained to 57 mph with gusts to 60 mph on the 21st.
In 2007…a brief hot spell produced two temperature records. The high temperature of 97 degrees was tied on the 20th. A new record high temperature of 99 degrees was established on the 21st.


In 1927…north winds were sustained to 40 mph with gusts to 44 mph.

In 1984…lightning struck and killed two children standing near a tree in a backyard in Lakewood. Strong thunderstorm downbursts caused a wind gust to 58 mph in Northglenn and knocked down two power poles near Brighton.

In 1988…lightning struck a home in Denver…causing about ten thousand dollars damage. Lightning damaged 3 homes in Littleton…and also hit a house in greenwood village that had been struck by lightning 7 years previously.

In 1991…thunderstorms produced widespread hail across metro Denver. Hail as large as 2 1/2 inches fell at several locations across southwest metro Denver. One storm spotter reported hail 8 inches deep near the intersection of I-25 and C-470. Heavy rain with the storms caused some street flooding. In Commerce City…several cars were under water… And in Westminster a police officer reported water up to the doors of his car. Damage to homes and automobiles totaled 55 million dollars.

In 1992…a tornado touched down briefly near Bennett. Another tornado was briefly on the ground near Strasburg.

In 1994…heavy thunderstorm rains caused flooding in metro Denver. Several vehicles were stalled in the high water on I-25. Lightning struck an underground natural gas line in Aurora…causing a fire. Widespread power outages were also observed.

In 1996…three homes were struck by lightning in Parker. The lightning struck the garage of the first home…which started a small fire that burned some siding and spread into the attic. A second home sustained damage to the attic when a small fire was started. The third home received only minor damage. Lightning also sparked two small grass fires in the area. A man in Lakewood received minor injuries when he was struck by lightning while working on a ladder. A funnel cloud was sighted in Castle Rock. Strong thunderstorm winds downed a large tree near crossroads mall in Boulder. A small tornado (f0) briefly touched down near Lafayette. No damage was reported.

In 1997…one inch diameter hail was measured in Boulder.

In 2002…a thunderstorm wind gust to 62 mph was recorded at Denver International Airport.

In 2005…severe thunderstorms produced hail to 1 inch in diameter in Broomfield along with 3/4 inch hail near Arvada.

In 2006…a man riding a motorcycle was struck and killed by lightning on U.S. Highway 36 between church ranch Blvd. And Sheridan Blvd. In Westminster. After the biker was struck…he and his motorcycle crashed into the center concrete median of the highway. The lightning bolt left a crater in the highway asphalt that measured 18 inches long…8 inches wide and 4 inches deep.

2010…A severe thunderstorm produced hail up to 1 1/2 inches in diameter near Morrison. In Lafayette and Louisville, hail up to one inch in diameter was observed.

2014…Three small tornadoes touched down in eastern Adams County near Barr Lake, Bennett and Front Range Aiport. The tornado near Barr Lake damaged some out buildings and a storage shed. Minor roof damage to houses in the immediate area was reported near 168th Ave and Haymont Rd near 168th Ave and Haymont Rd. It was rated an EF1. The others did no damage.


In 1941…strong thunderstorms produced cloudbursts of rain in Boulder County…starting during the late evening of the 21st and continuing overnight. The heavy rains over the Boulder creek…left hand creek…and south St Vrain River basins produced flooding in already swollen streams and turned dry gulches into raging torrents. The force of the floodwaters swept a man from the arms of his wife to his death…severely damaged canyon homes and swept others away… And hurtled a car down a steep embankment after the driver narrowly escaped. West of Boulder…the Boulder canyon highway was littered with rocks and debris and collapsed when two culverts were washed away. The flood waters washed much debris down four mile canyon…damaging the road near the creek bed. A bridge over dry creek just south of Niwot was completely washed away.

In 1964…scattered hail and rain caused property damage and local flooding in Boulder.

In 1989…an unseasonably cold weather system produced strong winds over much of metro Denver and snowfall in the foothills as low as 7500 feet elevation. One to 6 inches of snow fell in the foothills west of Denver with 15 inches reported on the summit of Mount Evans. Six inches of snow were measured at Conifer. Rainfall totaled only 0.09 inch at Stapleton International Airport where northwest winds gusted to 29 mph on the 21st.


In 2002…the maximum temperature in Denver equaled or exceeded 90 degrees for 13 consecutive days…equaling the 5th longest such streak on record. The record of 18 consecutive days was set during the summer of 1901.


In 1872…small sandstorms…frequently seen on the prairie… Occasionally passed through the city.

In 1983…3/4 inch hail was observed at Deckers…and a thunderstorm produced wind gusts to 55 mph at Littleton.

In 1988…a tornado was spotted one mile east of Brighton; it remained on the ground for about 6 minutes…but did no reportable damage. Lightning damaged a home near Castle Rock.

In 1991…thunderstorms produced golf ball size hail in Lafayette. The strongest storms occurred north of metro Denver.

In 1992…nickel size hail was reported just east of Parker.

In 1995…large hail 3/4 to 1 3/4 inches in diameter fell in Castle Rock where a funnel cloud was sighted. Hail 3/4 inch to 1 inch in diameter fell in south Denver and Aurora. A funnel cloud was also sighted over Chatfield Reservoir. In Bennett…very strong dry microburst winds of unknown speeds ripped a 14- by 48-foot metal roof off of a barn. The roof was tossed approximately 250 yards. A few 150- pound railroad ties were moved 10 to 15 feet.

In 1997…a tornado touched down near the Adams County fairgrounds northeast of Denver…uprooting several trees and damaging a car. A dry microburst produced a brief wind gust to 69 mph at Jefferson County airport. A small brief tornado was sighted near Hudson…but did no reported damage.

In 1998…3/4 inch hail fell near Hudson.

In 1999…thunderstorm winds gusted to 63 mph at Denver International Airport.

In 2003…hail as large as 2 inches in diameter was measured in Fort Lupton with 3/4 inch hail in Erie and near Boulder.

In 2006…a small tornado (f0) touched down near Franktown… But caused no damage.

In 2008…strong winds from dry microbursts developed over parts of southern Weld and western Arapahoe counties. A peak gust of 60 mph was observed in centennial. Near Frederick…strong winds snapped 3 power poles and sparked a small grassfire near State Highway 52 and interstate 25. At Denver International Airport…a peak gust of 31 mph was observed.


2012…The maximum temperature exceeded 100 degrees for five consecutive days. Two of the high temperatures on the 25th and 26th peaked at 105 degrees, which set the all time record for the month of June and tied the all time maximum temperature for Denver.

» Click here to read the rest of June 21 to June 27: This week in Denver weather history

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Lots of sun, unseasonably warm temperatures for Thornton’s Wednesday

Wednesday, June 24th, 2020 4:28am MDT

We see a bit of a return of the heat today. Temperatures will return to levels a good ways above normal and we have only the slightest of chance for a PM thunderstorm.

Sunny skies start us off and will be with us for the morning. The afternoon brings a few clouds. There will be a brief window around mid-afternoon when a few thunderstorms may be seen but coverage will be widespread. High temperatures today will push into the low to mid-90s.

Tonight, partly cloudy skies will be above with lows around 60 degrees.

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Tuesday brings seasonal temperatures, some isolated thunderstorm activity

Tuesday, June 23rd, 2020 4:56am MDT

A relatively pleasant, early summer day for Thornton. Temperatures will top out right near normal today and we have just a slight chance for some PM storms.

Mostly sunny skies start us off followed by a gradual increase in clouds in the afternoon. High temperatures will top out in the low to mid-80s. After noon we will see some thunderstorms develop but coverage will be limited.

Tonight, a few storms may be seen until about 11:00pm then skies will begin to clear. Overnight lows will be in the upper 50s.

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