All posts by Thornton Weather

ThorntonWeather.com is your local source for live Thornton, Colorado weather conditions and news!

Monday continues the mild, dry weather but with a good bit of cloud cover

The lack of drama in these forecasts makes writing them quite boring. ?  We will continue to enjoy well above normal temperatures today with the only notable change being the clouds.

With a good bit of moisture aloft, mostly cloudy skies will be the rule throughout the daytime hours today. Conditions will be calm and dry. High temperatures will again reach the mid-50s.

Tonight, we continue to be calm and the cloud cover will ease. Lows will dip to around 30 degrees.

December 2024 top shots: Monthly photo slideshow

December 4, 2024 - The crescent moon and Venus in the evening sky. (Al Feuerborn)
December 4, 2024 – The crescent moon and Venus in the evening sky. (Al Feuerborn)

The month of December can offer everything from bone dry conditions to bone chilling cold and monstrous snowstorms.  The weather and wildlife all afford an abundance of photo opportunities as our December photo slideshow shows.

Leaves have fallen from trees now and the landscape can sometimes look quite stark.  However it only takes a quick shot of snow to change that picture greatly.  Throw in gorgeous sunrises and sunsets, plenty of wildlife big and small, kids playing and much more and the month can be quite colorful and eventful.

  • Slideshow updated December 22, 2024
  • To learn more about how to send your photo to us for inclusion in the slideshow, see below the slideshow.

Showcasing images captured by ThorntonWeather.com readers as well as some of our own, our monthly slideshow covers the entire gamut of weather-related imagery.

Sunsets, sunrises, wildlife and of course every type of weather condition are vividly depicted in images captured from yours and our cameras.

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!

December 22 to December 28: This Week in Denver Weather History

This Week in Denver Weather History

The period around the Christmas holiday has historically been a pretty eventful one for the Denver metro area. Our look back at this week in Denver weather history showcases a wide variety of extreme conditions. From powerful, damaging winds to extreme cold to monstrous blizzards, we can and have seen it all.

From the National Weather Service:

17-24

In 1924…a prolonged cold spell occurred after mild temperatures during the first half of the month. Most low temperatures dipped below zero with the coldest reading of 15 degrees below zero occurring on the 24th. The high temperature of only 5 degrees on the 18th was a record low maximum for the date.

18-24

In 1998…a vigorous cold front with north winds gusting as high as 38 mph at Denver International Airport on the 18th dropped temperatures from a high of 51 degrees to a low of just 6 degrees before midnight. The arctic air mass that settled over metro Denver produced intermittent light snow and a week-long protracted cold spell that caused low temperatures to plunge well below zero for 6 consecutive nights. The coldest temperature was 19 degrees below zero on the morning of the 22nd. High temperatures climbed only into the single digits on 4 consecutive days…from the 19th through the 22nd. At least 15 people…mostly homeless… Were treated for hypothermia at area hospitals. The bitter cold weather was responsible…either directly or indirectly… For at least 5 fatalities. Three of the victims died directly from exposure. The cold weather also caused intermittent power outages. Following the cold snap… Thawing water pipes cracked and burst in several homes and businesses…causing extensive damage. Only one temperature record was set. The high temperature of only 7 degrees on the 19th set a record low maximum for the date.

19-23

In 1990…a surge of very cold arctic air invaded metro Denver. Many temperature records were broken as the mercury remained at or below zero for 85.5 hours at Stapleton International Airport…making it the third longest period of subzero readings in 118 years of record keeping. On the morning of the 22nd…the mercury plunged to 25 degrees below zero…which equaled the all-time record low temperature for the month set on December 24…1876. In the foothills southwest of Denver at tiny town…the mercury plunged to 33 degrees below zero on the morning of the 21st. On the same morning at Castle Rock the temperature dipped to 26 degrees below zero. During the period…other daily temperature records were set at Denver…including: record low maximum of 3 degrees below zero on the 20th and a record low of 17 degrees below zero on the 23rd. The record low was equaled with 16 degrees below zero on the 20th and 21 degrees below zero on the 21st. Snowfall totaled 2.7 inches at Stapleton International Airport from the 19th through the 21st.

20-22

In 1933…strong downslope winds produced a warm spell. Low temperatures of 43 degrees on both the 20th and 21st and 41 degrees on the 22nd were record high minimums for those dates. High temperature of 67 degrees on the 21st was a record maximum for the date. High temperatures of 56 degrees on the 20th and 69 degrees on the 22nd were not records; however…the 69 degrees was the warmest of the month. West to northwest winds were sustained to 20 and 24 mph on the 21st and 22nd respectively.

20-23

In 1918…light snowfall on each day totaled 12.0 inches over downtown Denver. Northeast winds were sustained to 16 mph on the 21st.

20-25

In 1983…an extremely bitter cold spell occurred. The temperature remained below zero for 115 hours in Denver… The longest sub-zero period on record. The mercury dipped to 21 degrees below zero on the 21st…the coldest recorded temperature in over 20 years. The cold was accompanied by winds that plunged chill factors to 50 to 70 degrees below zero. Two people froze to death in Denver; both were found outside dead of exposure. Numerous cases of frostbite were reported. Hundreds of water pipes broke from the intense cold…water mains and natural gas lines also fractured…and electricity consumption reached record levels. Light snow totaling 5.8 inches fell at times…and holiday traffic was delayed at Stapleton International Airport for several hours. Eight daily temperature records were set at the time. The all-time record low maximum temperature for the month of 8 degrees below zero on the 21st still stands today. Other temperature records still standing include record low maximum temperatures of 5 degrees below zero on both the 22nd and 23rd and 4 degrees below zero on the 24th.

21-22

In 1969…strong winds raked the eastern foothills in Boulder and Jefferson counties. Wind gusts to 115 mph were recorded at the National Center for Atmospheric Research in Boulder…while in downtown Boulder winds gusted to 75 mph. Some damage occurred.

In 1981…a snow storm dumped 3 to 8 inches of snow across eastern Colorado. Snowfall totaled 6.8 inches at Stapleton International Airport where north winds gusted to only 17 mph.

In 2011…large scale lift from an upper level low combined with a deep easterly upslope flow behind a cold front to produce heavy snow in and near the Front Range foothills and Palmer Divide. Storm totals ranged from 1.5 to 3 feet in the Front Range foothills…with 1 to 1.5 feet along the urban corridor. In the Front Range foothills and Palmer Divide…storm totals included: 36.5 inches…7 miles southwest of Boulder; 32 inches…12 miles northwest of Golden; 28 inches at Genesee; 24.5 inches…3 miles west of Jamestown; 23 inches at Bergen Park; 21 inches at Evergreen and Gross Reservoir; 19 inches near Eldorado Springs and 3 miles west-southwest of Conifer; 17 inches…4 miles south- southwest of Tiny Town; and 13.5 inches…15 miles north of Elizabeth. Along the urban corridor…storm totals included: 18 inches in Golden; 14.5 inches in Boulder…13 inches at the National Weather Service in Boulder; 12.5 inches…5 miles south-southwest of Arapahoe Park; 12 inches at Lone Tree; 11.5 inches in Broomfield; 11 inches in Arvada…4 miles northwest of Elbert…Niwot and Wheatridge; 10 inches in northwest Denver; with 7.3 inches at Denver International Airport.

21-23

In 1924…heavy snowfall totaled 7.9 inches over downtown Denver. During the storm north to northeast winds were sustained to 21 mph. Temperatures were quite cold…ranging from a high of 24 degrees on the 21st to a low of 5 degrees below zero on the 23rd.

In 1964…high winds were recorded along the eastern foothills. A wind gust to 100 mph was registered at Jefferson County Airport near Broomfield. In Boulder… Where many thousands of dollars in damage occurred…warm Chinook winds gusted in excess of 45 mph downtown. A wind gust to 82 mph was recorded at the National Center for Atmospheric Research in Boulder. Heavy damage to power lines…homes…and roads was reported at Evergreen…Golden… And Boulder. Several people were injured by wind-caused accidents. West winds gusted to 53 mph on the 22nd and to 51 mph on the 23rd at Stapleton International Airport where some blowing dust occurred. The Chinook winds warmed temperatures in Denver to highs of 68 degrees on the 22nd and 71 degrees on the 23rd.

Continue reading December 22 to December 28: This Week in Denver Weather History

Astronomical winter arrives Saturday, offers up the shortest day of the year

The Winter Solstice
Winter officially begins at 2:21am MST on Saturday, December 21, 2024.

Astronomical winter arrives in Thornton early Saturday morning and with the solstice also comes the shortest day of the year.

Winter officially begins at 2:21am MST on Saturday, December 21, 2024.

The Winter Solstice occurs when the North Pole is tilted at its furthest from the sun – 23.5 degrees away. This results in the shortest day of the year in the Northern Hemisphere.

Here in Denver, with sunrise at 7:17am and sunset at 4:39pm, our day Saturday will be 9 hours, 21 minutes and 15 seconds long.

The following day, Sunday, it will be about three seconds longer and each day from now through to the Summer Solstice in June will get gradually longer as well.

While we have a short day on the solstice, it is nothing like what will be experienced in the Arctic Circle.  Areas north of there to the North Pole will have no direct sunlight at all.  Conversely, areas south of the Antarctic Circle toward the South Pole will have 24 hours of daylight and have a midnight sun.

Did you know that there is a difference between the astronomical seasons that we are discussing here and meteorological seasons?

Meteorological seasons differ slightly and are geared toward matching the calendar with the annual temperature cycle. This is done primarily for meteorological observing and forecasting and in many ways it is more logical than the astronomical seasons.

For the Northern Hemisphere, the meteorological spring covers the months of March, April and May. Summer brings the hottest months of the year and so meteorological summer is June, July and August. Meteorological fall then is September, October and November followed by the coldest months of December, January and February as meteorological winter.

Denver’s Christmas weather history shows it isn’t usually a white one

Historical probability of at least 1 inch of snow on the ground on Christmas. (NOAA)
Historical probability of at least 1 inch of snow on the ground on Christmas. (NOAA)

As Christmas gets closer everyone always wonders if we are going to get the proverbial white Christmas. Unfortunately, if you look at Denver and Thornton weather history, the chances aren’t all that good but it also depends on what you define as a white Christmas.

If to you a white Christmas means having actual snowfall on Christmas Day the chances are pretty poor. But, if simply having snow on the ground suffices, the chances improve considerably.

For a complete look at Denver’s Christmas weather statistics, click here.

For the latest Thornton weather forecast for Christmas, check out our forecast page.

December 15 to December 21: This Week in Denver Weather History

This Week in Denver Weather History

Powerful, damaging wind, deadly cold and monster snowstorms are the highlights of this week in Denver weather history.

From the National Weather Service:

12-15

In 1921…downslope Chinook winds produced warm temperatures in the city…which resulted in 4 temperature records. High temperatures of 72 degrees on the 13th and 68 degrees on the 15th were record maximums for the dates. Low temperatures of 47 degrees on both the 12th and 13th were record high minimums for the dates. West winds were sustained to 38 mph on the 12th and to 25 mph on the 13th.

14-15

In 1988…a snow storm again whitened metro Denver. Snowfall along the Front Range was in the 6 to 12 inch range. Snowfall totaled 5.8 inches at Stapleton International Airport where north winds gusted to 38 mph.

In 1990…high winds howled across metro Denver behind a strong pacific cold front. Boulder was hardest hit by the high winds. A wind gust to 120 mph was recorded in south Boulder where winds stripped the roof off a garage…a vacant gas station…and a house under construction. Elsewhere in Boulder…several trees were blown down. In Boulder canyon…the winds toppled two cinder block walls on a house under construction. Four Boulder County women were treated for injuries caused by the wind. The injuries were confined to a broken wrist…a mild concussion…bruises…and facial cuts. Two semi-tractor trailers were blown over by the fierce winds south of Boulder. Another truck rollover occurred southeast of Golden. Drivers of all three trucks suffered only cuts and bruises. Several vehicles were trapped in a blinding dust storm on the Denver-Boulder turnpike near Broomfield. Drivers were forced to stop along the highway for several minutes during the storm and witness their vehicles being pelted with sand and gravel. A wind gust to 97 mph was recorded in Golden. High winds were also reported in Arvada…Boulder…and Lakewood. Winds toppled a number of utility poles and wooden fences…blew out windows…and caused structural damage to a large apartment complex on the west side of Golden. Wind gusts of 70 to 100 mph caused considerable damage to several large billboards north of Golden…as well as damaging the paint…trim…and glass on numerous vehicles in the area. A west wind gust to 51 mph was recorded at Stapleton International Airport.

15

In 1999…high winds developed in and near the foothills as a strong upper level jet moved into the area. Although most wind gusts were in the 70 to 80 mph range…a weather spotter located 1 mile south of Fritz Peak near Rollinsville measured a peak wind gust to 124 mph. Other wind reports included wind gusts to 77 mph at the National Center for Atmospheric Research in Boulder and atop Blue Mountain and 70 mph at the national wind technology center on Rocky Flats south of Boulder. West winds gusted to only 32 mph at Denver International Airport.

In 2000…high winds developed in the foothills of Boulder County…but winds were strong across all of metro Denver. Winds gusted as high as 72 mph at the National Center for Atmospheric Research on the mesa just southwest of Boulder. West winds gusted to 44 mph at Denver International Airport.

In 2021…a powerful cold front moved across northern Colorado in the morning. Bands of moderate to heavy snow showers in the mountains resulted in early morning snow squalls. Colorado Department of Transportation had brief road closures along with parts of I-70 due to the limited visibility and hazardous road conditions that accompanied the snow squalls. Storm totals in the mountains generally ranged from 3.5 to 6.5 inches. As the cold front swept across the Front Range Foothills…Urban Corridor…and adjacent plains…very strong post-frontal or bora winds developed. The strongest wind gusts ranged from 70 to 95 mph occurred in and near the foothills…and along and north of the I-76 corridor. At Denver International Airport…a peak wind gust to 60 mph was observed from the northwest. There were overturned semis reported on I-25…and car window were blowing out in Boulder and Broomfield. Denver International Airport reported 2219 flight cancellations and 12327 delays. Xcel Energy power outages peaked at about 63000 customers during this high wind event. The high winds knocked down several trees… with blowing dust and reduced visibility northeast and east of Denver. Some trees reportedly crashed into nearby homes and onto parked vehicles.

15-16

In 1964…high winds raked metro Denver…causing considerable damage. Wind gusts to 81 mph were recorded at Rocky Flats northwest of Denver…94 mph at Jefferson County Airport near Broomfield…48 mph in downtown Boulder…and 70 mph in Littleton. West wind gusts to 67 mph were recorded at Stapleton International Airport. A man working on construction in downtown Denver died from injuries after being struck by a 5-foot by 8-foot section of plank runway blown by the strong winds. Several people were blown down by the strong winds or hit by flying objects. Buildings… Roads…trees…and power equipment were damaged. Roads were closed east of Denver due to blowing dust.

In 1981…wind gusts to 60 mph were common in the foothills northwest of Denver. West wind gusts to 47 mph were recorded at Stapleton International Airport where the visibility was briefly reduced to 3 miles in blowing dust.

In 1996…strong pre-frontal winds developed in the foothills of Boulder County ahead of an arctic cold front that moved into northeastern Colorado late on the morning of the 16th. Wind gusts of 70 to 75 mph were clocked at Table Mesa in southwest Boulder.

16

In 1912…northwest winds were sustained to 44 mph with an extreme velocity of 45 mph.

In 1921…north winds were sustained to 46 mph with gusts to 50 mph behind a vigorous cold front. Only a trace of snow fell.

In 1954…a vigorous cold front produced sustained north winds to 45 mph with gusts as high 54 mph. Visibility was reduced to 1 mile in blowing dust at Stapleton Airport.

In 1955…sustained west winds to 44 mph with gusts as high as 58 mph were recorded at Stapleton Airport.

In 1994…a wind gust to 108 mph was recorded atop Squaw Mountain west of Denver with a gust to 92 mph in Rollinsville southwest of Boulder. West winds gusted to 48 mph at Stapleton International Airport.

In 1996…a vigorous arctic cold front moved across metro Denver. Heavy snow and strong winds accompanied the front as near whiteout conditions in snow and blowing snow developed suddenly. Northerly winds gusted from 40 to 60 mph behind the front. Dozens of accidents occurred as roads and highways quickly turned to a glaze of ice. Snowfall amounts ranged from 4 to 6 inches across metro Denver and in the foothills. The exception was at Eldorado Springs south of Boulder where 8 inches of new snow were measured. Snowfall totaled only 1.8 inches at the site of the former Stapleton International Airport. Officially…this was the only measurable snow of the month in Denver. At Denver International Airport…north winds gusted to 34 mph.

In 1999…another brief round of high winds developed in and near the foothills of Boulder County. Peak wind gusts included 83 mph at the National Center for Atmospheric Research near Boulder and 74 mph atop Niwot Ridge and at the National Wind Technology Center on Rocky Flats south of Boulder. West winds gusted to only 33 mph at Denver International Airport where the temperature warmed to a high of 54 degrees.

In 2000…high winds in the mountains spread into the foothills west of Denver. Winds gusted to 87 mph at Georgetown Lake and at the National Center for Atmospheric Research in Boulder. Winds gusted to 72 mph at the national wind technology center south of Boulder.

16-17

In 1908…heavy snowfall totaled 7.9 inches in downtown Denver where north winds were sustained to 20 mph on the 17th. Temperatures were in the teens and 20’s.

In 1939…low temperatures of 49 degrees on the 16th and 43 degrees on the 17th were record high minimums for the dates. High temperatures of 65 on the 16th and 72 on the 17th were not records.

In 1980…Chinook winds blew through the night in Boulder with a peak reported gust to 75 mph. Northwest winds gusted to 30 mph at Stapleton International Airport on the 17th. The strong Chinook winds warmed temperatures to record daily highs of 70 degrees on the 16th and 73 degrees on the 17th.

In 2016…the presence of a warm and moist southwesterly flow aloft…overrunning an Arctic airmass with shallow post frontal upslope produced a band of very heavy snowfall across the Denver metro area. The enhanced band of heavy snow extended west into the Front Range mountains and foothills with snowfall rates up to 2 inches per hour. Multiple accidents occurred during the evening hours of the 16th as the snow quickly piled up. Three hundred flights were canceled at Denver International Airport as the winter storm moved through the Denver metro area early morning hours of the 17th. Storm totals in the Front Range mountains and foothills included: 16 inches at Loveland Ski Area; 12 inches near Conifer…11 inches at Winter Park Ski Area…10.5 inches at Bergen Park… 10 inches at Echo Lake…with 9.5 inches at Aspen Springs and Evergreen. In and around metro Denver…storm totals included: 11.5 inches in Wheat Ridge…11 inches in Arvada… 9 inches near Morrison…8 inches at Denver International Airport…Denver/Stapleton…Marston Reservoir and Ralston Reservoir; 7.5 inches in Westminster; 6.5 inches…5 miles northeast of Westminster; 6 inches in Aurora…5 miles west-northwest of Brighton…Englewood and near Louisville.

17

In 2000…high winds gusting from 60 to 74 mph howled across the northeast plains of Colorado. In Parker where winds gusted to 60 mph…a 20-foot by 40-foot piece of roof was ripped from a building. West winds gusted to 53 mph at Denver International Airport. This was the highest wind gust of the month at the airport. An intense…but very localized wind gust to 112 mph was measured near Georgetown lake in the foothills west of Denver.

17-24

In 1924…a prolonged cold spell occurred after mild temperatures during the first half of the month. Most low temperatures dipped below zero with the coldest reading of 15 degrees below zero occurring on the 24th. The high temperature of only 5 degrees on the 18th was a record low maximum for the date.

18

In 1901…north winds were sustained to 52 mph with gusts to 58 mph behind an apparent cold front.

In 1973…a brief blizzard dumped heavy snow across metro Denver. Snowfall totaled 9.2 inches at Stapleton International Airport where north winds gusting to 53 mph produced much blowing snow. The storm forced many schools and businesses to close.

In 1996…a homeless man in Denver was found unconscious in his car suffering from exposure. The man’s body temperature was only 85 degrees when he was discovered. He died several hours later. Early morning temperatures had dipped to 9 degrees below zero.

In 1999…high winds were reported for a brief time in the foothills. Winds gusted to 72 mph in Golden Gate Canyon and to 71 mph at the National Center for Atmospheric Research in the foothills southwest of Boulder. West winds gusted to only 39 mph at Denver International Airport where the temperature warmed to a high of 53 degrees.

In 2002…only a trace of snow fell at the site of the former Stapleton International Airport. This…along with the trace of snow on the 5th…was the only snow of the month…ranking the month the 2nd least snowiest on record.

18-19

In 2012…a storm system brought moderate to heavy snow to the mountains and foothills west of metropolitan Denver and blizzard conditions to plains east of Denver metro area. The combination of snow and wind reportedly reduced visibility to just a few hundred feet at times…and resulted in several road closures including interstate 70 east of Aurora. East of Denver gusty northerly winds ranged from 35 to 55 mph produced extensive blowing and drifting snow…ranging from 1 to 4 feet in depth. Storm totals ranged from 3 to 5 inches. In the mountain and foothills…the heaviest snowfall occurred along and north of I-70 and included: 12 inches at Genesee…9 inches near Eldorado Springs; 8.5 inches at Coal Creek Canyon…8 inches near Evergreen…with 6 inches at Eldora Ski Area…Idaho Springs…Gross Reservoir and Nederland. At Denver International Airport…1.7 inches of snowfall was observed. In addition…a peak wind gust to 35 mph was observed from the north on the 19th.

18-21

In 2010…a winter storm produced a 4-day period of moderate to heavy snow in the mountains. The combination of strong wind and heavy snow forced the closure of several mountain passes due to the threat of avalanches. The Amtrak train route… Which runs from Denver to California…was rerouted through Wyoming when Union Pacific closed its tracks along interstate 70. Numerous accidents forced the closure of I-70 at times. The wind gusted to 60 mph over the higher mountain passes. Storm totals in the ski areas west of Denver ranged from 16 to 32 inches.

18-24

In 1998…a vigorous cold front with north winds gusting as high as 38 mph at Denver International Airport on the 18th dropped temperatures from a high of 51 degrees to a low of just 6 degrees before midnight. The arctic air mass that settled over metro Denver produced intermittent light snow and a week-long protracted cold spell that caused low temperatures to plunge well below zero for 6 consecutive nights. The coldest temperature was 19 degrees below zero on the morning of the 22nd. High temperatures climbed only into the single digits on 4 consecutive days…from the 19th through the 22nd. At least 15 people…mostly homeless… Were treated for hypothermia at area hospitals. The bitter cold weather was responsible…either directly or indirectly… For at least 5 fatalities. Three of the victims died directly from exposure. The cold weather also caused intermittent power outages. Following the cold snap… Thawing water pipes cracked and burst in several homes and businesses…causing extensive damage. Only one temperature record was set. The high temperature of only 7 degrees on the 19th set a record low maximum for the date.

Continue reading December 15 to December 21: This Week in Denver Weather History

December 8 to December 14: This Week in Denver Weather History

This Week in Denver Weather History

A little bit of everything in the history books for this week in Denver weather history. We see a prolonged period of nearly spring-like temperatures and on the opposite end, multiple occasions of bitter cold. There have been, of course, some significant snowfalls as well.

From the National Weather Service:

2-17

In 1939…more than 2 weeks of unseasonably warm weather made the month the 3rd warmest on record. Seven daily temperature records were set…including the all-time record high temperature for the month of 79 degrees on the 5th. Daytime highs were balmy with 14 days in the 60’s and 70’s. Low temperatures dipped to freezing or below on only 5 days. The period was dry with only a trace of snow on the 12th.

3-15

In 1972…a protracted cold spell held an icy grip on metro Denver when maximum temperatures never reached above freezing for 10 consecutive days from the 3rd through the 12th and minimum temperatures dipped below zero on eleven consecutive days from the 5th through the 15th. Daily low temperature records were set with 15 degrees below zero on the 5th…17 degrees below zero on the 6th… And 18 degrees below zero on the 10th. Daily record low maximum readings were set with 3 degrees on the 6th and 6 degrees on the 9th. The very cold temperatures were caused by 3 to 5 inches of snow cover and a Canadian air mass.

5-8

In 1983…high winds occurred in and near the foothills each day. Wind gusts to 63 mph were registered in Golden Gate Canyon on the evening of the 5th. On the evening of the 6th…winds knocked down trees…snapped power lines…and blew out windows across metro Denver. Gusts were clocked to 102 mph in southwest metro Denver…while wind gusts to 38 mph were recorded at Stapleton International Airport. On the 7th…winds overturned a tractor trailer near Castle Rock. After midnight on the 8th…gusts to 97 mph were reported in southeast Boulder. Wind speeds of 60 to 70 mph were reported in other parts of metro Denver.

7-9

In 1919…an apparent arctic cold front brought extreme cold and light snow to the city. Snowfall totaled only 2.5 inches on the 7th and 8th. Temperatures dipped to lows of 14 degrees below zero on the 8th and to 20 degrees below zero on the 9th. Both readings were daily record minimums. High temperatures were only 4 degrees on the 8th and 7 degrees on the 9th.

In 1923…a major storm dumped 13.5 inches of snowfall on downtown Denver. The apparent post-frontal snowfall started during the late afternoon of the 7th and continued through the evening of the 9th. Temperatures dipped from a high of 66 degrees on the 7th with west winds sustained to 35 mph to a low of only 14 degrees on the 9th…with north winds sustained to 25 mph.

8

In 1880…severe winds buffeted the eastern foothills…causing some damage in Boulder.

In 1987…high winds damaged a chimney and roof of a house near Bergen Park in the foothills west of Denver. Gusts were estimated to 70 mph. Northwest winds gusted to 33 mph at Stapleton International Airport.

8-9

In 1943…4.5 inches of snow fell in downtown Denver. This was the only measurable snow of the month. North winds were sustained to 26 mph on the 8th.

In 2003…snowfall totaled 3 to 6 inches across metro Denver. Snowfall was heavier in and near the foothills with 8.0 inches measured in Boulder and 10 miles southwest of Sedalia. Snowfall was 3.9 inches at the site of the former Stapleton International Airport. Most of the snow fell on the 8th…as the snow ended shortly after midnight. North winds gusted to 29 mph at Denver International Airport.

In 2008…an upslope snowstorm produced heavy snow in and near the foothills of Boulder…Jefferson and Douglas counties… And along the palmer divide south of Denver. Storm totals in the foothills ranged from 8 to 15 inches. In Boulder and in areas west and south of Denver…storm totals ranged from 6 to 13 inches. The snowfall measurement at Denver International Airport was 3.9 inches.

8-10

In 1985 a slow moving storm dumped 10 to 20 inches of snow over the northeast plains…closing schools and businesses in many areas along the Front Range north of Denver. At Stapleton International Airport…snowfall totaled 9.9 inches with a maximum snow depth of 7 inches on the ground. North winds gusted to 24 mph. The snow caused long air traffic delays at Stapleton International Airport on the 9th.

In 1997…persistent light to moderate snowfall combined with strong and gusty northerly winds to produce much blowing and drifting snow across metro Denver. The hardest hit areas were south of Denver where north winds at speeds of 20 to 35 mph with gusts to 45 mph caused near whiteout conditions. The strong winds produced drifts 2 to 4 feet deep and dropped wind chill temperatures well below zero. Sections of both I-25 and I-70 and other roads were closed as travel became impossible due to blowing snow. Numerous traffic accidents were reported and a handful of people were stranded during the snowstorm. Snowfall totals included: 22 inches at Conifer…13 inches at Castle Rock…12 inches at Parker…and 8 inches in southeast Aurora. Snowfall totaled 5.5 inches at the site of the former Stapleton International Airport. North winds gusted to 36 mph at Denver International Airport on the 10th.

8-12

In 1932…the second longest sub-zero period on record in Denver occurred. The temperature fell below zero shortly after 1:00 pm on the 8th and remained below zero for 92 hours until 9:00 am on the 12th. The lowest temperature recorded during this period was 13 degrees below zero on both the 9th and 11th. That temperature on the 11th was a record low for the date. High temperatures of 4 on the 8th…5 below zero on the 9th…1 below zero on the 10th… And 6 below zero on the 11th were record low maximum temperatures for those dates. Light north winds at 5 to 10 mph were accompanied by occasional light snow…which totaled only 2.2 inches.

9

In 1898…the very cold air mass that settled over the city behind an apparent cold front on the 7th plunged temperatures to a low of 20 degrees below zero. The high temperature climbed to only 5 degrees.

In 1910…Chinook west winds sustained to 46 mph warmed the temperature to 60 degrees…the warmest reading of the month that year.

In 1919…the minimum temperature dipped to 20 degrees below zero in downtown Denver…setting a record low for the date.

In 1984…high winds occurred in the foothills with a gust to 69 mph recorded at Golden Gate Canyon west of Denver. West winds gusted to 36 mph at Stapleton International Airport.

In 1992…high winds were recorded over most of the day in the Front Range foothills. Wind gusts to 95 mph were measured in the Table Mesa area of Boulder. Northwest winds gusted to 43 mph at Stapleton International Airport.

In 1993…a weather observer in Boulder recorded a wind gust to 73 mph. North winds gusted to 37 mph at Stapleton International Airport.

In 1998…metro Denver and areas in the foothills received the first significant snowfall in more than a month. The upslope snow event deposited up to 17 inches in the foothills with generally 4 to 8 inches across metro Denver west of I-25. Snowfall totals included 17 inches at Crescent Park and 16 inches in nearby Coal Creek Canyon. Other snow amounts included: 16 inches at tiny town; 14 inches at Chief Hosa…Evergreen…and Genesee; 13 inches in Conifer; 12 inches at Nederland; 11 inches in Eldorado Canyon; 9 inches just west of Boulder; 8 inches in Boulder; and 7 inches in Broomfield and Golden. Only 3.6 inches of snow fell at the site of the former Stapleton International Airport. Northeast winds gusted to 26 mph at Denver International Airport.

9-13 Continue reading December 8 to December 14: This Week in Denver Weather History

November 2024 weather recap: We finally chill out, get a healthy dose of precipitation

Thornton, Colorado's November 2024 Temperature Summary. (ThorntonWeather.com)
Thornton, Colorado’s November 2024 Temperature Summary. (ThorntonWeather.com)

After eight months straight of above average temperatures and six months straight of below average precipitation, we finally broke the streaks in November. Temperatures cooled a good bit and we received well above normal levels of precipitation.

The first five days of the month continued the mild weather but we did receive some rain during that time which was welcome.  After that, we saw a somewhat prolonged period of unsettled weather. Over a four-day period from the 6th to the 9th we received 10.8 inches of snowfall. This marked our first snowfall of the season, nearly three weeks later than normal.

From there, we again entered a relatively mild period with dry conditions that lasted 17 days. Finally, on the 27th, we received another nice shot of snow (3.4 inches). The weather then became calm and pleasant for the Thanksgiving weekend.

For the month of November 2024, Thornton’s average temperature came in at 37.9 degrees. This was a good bit cooler than our running 18-year average for November of 39.6 degrees. Temperatures ranged from a high of 68.7 degrees on the 23rd down to a low of 15.3 degrees on the morning of the 28th.

Out at Denver International Airport where Denver’s official measurements are taken, the Mile High City saw an average temperature for the month of 38.2 degrees. This was below their long term November average of 39.4 degrees.

In terms of precipitation, between rain and melted snow, Thornton recorded a very healthy 1.76 inches for the month. This was far above our running average for November of 0.54 inches. It was, in fact, the wettest November we have recorded in 18 years.

The Mile High City saw 1.98 inches in their bucket, mainly due to higher snowfall out at the airport. This was well above Denver’s long term November average of 0.64 inches and was the 5th wettest November ever recorded in Denver.

As previously mentioned, snowfall was quite abundant. Thornton recorded 14.2 inches, more than double our 18-year November average of 6.2 inches. This made November 2024 the third snowiest November in our books over that period.

Denver bested us on the snowfall front with a whopping 23.3 inches at the airport. This was far above their long-term November average of 7.3 inches. It also put November 2024 into Denver’s record books as the 4th snowiest November ever recorded.

Click here to view Thornton’s complete November 2024 climate summary report.

Thornton, Colorado's November 2024 Precipitation Summary. (ThorntonWeather.com)
Thornton, Colorado’s November 2024 Precipitation Summary. (ThorntonWeather.com)

Thornton’s December 2024 preview: Winter arrives, typically with cold and snow

Thornton, Colorado's December Weather Preview

Recent months have, overall, been mostly warmer and drier than normal.  Last month we finally got a break with cooler temps and a healthy dose of snow.  What will December hold for us?

The month of December brings with it the official start of winter and oftentimes, colder and snowier weather conditions. It, however, can also offer unseasonably warm temperatures and bone dry conditions.  Given our recent mild and dry weather, we are certainly hoping for a change in the coming month.

Overall December’s monthly mean temperature of 31.2 degrees (1991 – 2020 averages) makes it our coldest month.  Snow is always on everyone’s mind this time of year but December is only our 3rd snowiest month behind March and November with an average of 8.0 inches of the white stuff.

Get all the details on Thornton’s December weather including a look back at historical events and a look at the long range forecast in our December weather preview here.

  • Stay up to date with Thornton’s weather: Be sure to ‘like’ us on Facebook and follow us on Twitter.

December 1 to December 7: This Week in Denver Weather History

This Week in Denver Weather History

Extreme weather in December is hardly unusual as long-time residents can attest to. The most common major events involve wind, cold or snow and sometimes all three at once was we can see in our look back at this week in Denver weather history.

From the National Weather Service:

30-1

In 1929…heavy snow blanketed the city. Snowfall totaled 9.8 inches downtown. North winds were sustained to 32 mph with gusts to 37 mph on the 30th.

In 1970…high winds blasted Boulder and the eastern plains. In Boulder…a wind gust to 112 mph was recorded at the National Center for Atmospheric Research with a gust to 96 mph at the National Bureau of Standards.

In downtown Boulder…wind gusts reached 76 mph. At Stapleton International Airport…winds gusted to 47 mph. The high winds caused widespread light to moderate property damage across most of metro Denver. Roofs…signs…trees…power lines…and other property were damaged. Blowing dust reduced visibility to near zero over most of eastern Colorado. Several mobile homes…campers…and semi- trailers were blown off the highways north of Denver.

In 1985…an intrusion of cold arctic air into metro Denver resulted in setting 3 temperature records. The temperature climbed to only 17 degrees on the 30th…setting a record low maximum for the date. On the 1st…the temperature plunged to 6 degrees below zero…setting a record low for the date… And warmed to only 7 degrees…setting a record low maximum for the date.

30-2

In 1975…very strong Chinook winds up to 100 mph caused damage to homes…aircraft…aircraft hangars…mobile homes… Cars…and power lines along the eastern foothills. Strong northwest winds gusted to 39 mph at Stapleton International Airport on both the 30th and the 1st.

1

In 1899…northwest Chinook winds were sustained to 47 mph with gusts to 60 mph. The strong Chinook winds warmed the temperature to a high of 61 degrees…the warmest of the month. The low temperature dipped to only 39 degrees.

In 1972…strong Chinook winds gusted in excess of 65 mph in Boulder. There were no reports of damage. Northwest winds gusted to 38 mph at Stapleton International Airport.

In 1992…strong winds continued through the early morning hours. Wind gusts to over 70 mph were measured at reporting sites in the foothills west of Denver. In west Boulder…wind gusts reached 71 mph with 77 mph measured at Rollinsville. At Stapleton International Airport northwest winds gusted to 39 mph. The walker ranch…an historic site west of Boulder…burned down overnight during the high wind event. Although the winds did not cause the fire…they did hamper efforts to extinguish the blaze.

In 1996…high winds howled in and near the Front Range foothills. Winds gusted to 105 mph at Wondervu southwest of Boulder and to 70 mph at Jefferson County Airport near Broomfield. West winds gusted to only 24 mph at Denver International Airport.

1-2

In 1933…apparent post-frontal heavy snowfall totaled 8.0 inches across downtown Denver. North winds were sustained to 17 mph with an extreme velocity to 18 mph on the 1st.

In 1981 strong winds gusted to over 70 mph along the foothills. A peak gust to 100 mph was recorded at Wondervu. A gust to 94 mph was recorded just west of Boulder. Roofs on houses were damaged in the Evergreen area…and some mobile homes also were damaged. At Stapleton International Airport…northwest winds gusted 44 mph on the 1st and 37 mph on the 2nd.

1-5

In 1913…the 1st marked the start of the heaviest 5-day total snowfall in the city’s history. During this period snowfall totaled 45.7 inches. Starting on the 1st…snow fell intermittently for 3 days and accumulated a little over 8 inches. On the 4th and 5th…an additional 37.4 inches of snow fell. At Georgetown in the foothills west of Denver even more snow fell…86 inches over the 5 days with the most…63 inches…on the 4th. In Colorado…snowfall was heavy along the eastern slopes of the mountains from the Palmer Divide north. High winds during the storm caused heavy drifting…which blocked all transportation. Snow cover of an inch or more from the storm persisted for 60 consecutive days from the 1st through January 29…1914. Additional snowfall in December and January prolonged the number of days. This is the third longest period of snow cover on record in the city.

2

In 1893…northwest winds were sustained to 42 mph with gusts to 46 mph. Snowfall was only 1.4 inches in the city.

In 1895…0.01 inch of melted snow from 0.7 inch of snowfall was the only measurable precipitation of the month in downtown Denver…ranking the month the 3rd driest December on record.

In 1899…post-frontal northeast winds sustained to 44 mph with gusts to 59 mph caused the temperature to plunge from a high of 55 degrees to a low of 15 degrees. Snowfall was only 1.0 inch.

In 1902…apparent post-frontal northwest winds were sustained to 45 mph with gusts to 53 mph. A trace of snow fell.

In 1905…only a trace of snow fell in downtown Denver. This was the only snow and precipitation for the month… Ranking the month the second driest and the second least snowiest December on record.

In 1921…snowfall was 5.5 inches in downtown Denver. Northwest winds were sustained to 24 mph with an extreme velocity of 25 mph.

In 1951…a vigorous pacific cold front produced a northwest wind gust to 51 mph at Stapleton Airport where brief blowing dust was observed.

In 1957…a strong Pacific cold front produced northwest wind gusts to 54 mph at Stapleton Airport where the surface visibility was briefly reduced to 1 1/2 miles in blowing dust.

In 1977…high winds in Boulder lifted a warehouse from its foundation and ripped it apart. Wind gusts from 60 to 103 mph toppled and injured a man while walking. Winds were clocked to 104 mph at Nederland…100 mph at Morrison…and 62 mph at Rocky Flats. Northwest winds gusted to 41 mph at Stapleton International Airport.

In 1996…for the second day in a row high winds ripped the Front Range foothills. Winds gusted to 81 mph in Golden Gate Canyon. West-northwest winds gusted to 37 mph at Denver International Airport.

In 2013…high winds developed ahead of an approaching storm system. The strong winds downed several trees around Evergreen. Peak wind gusts included: 79 mph…4 miles west-southwest of Eldorado Springs; 78 mph…3 miles south of Evergreen; 75 mph and the NCAR Mesa Lab; and 69 mph in Longmont.

2-3

In 1955…snowfall totaled only 2.9 inches at Stapleton Airport. This was the only measurable snowfall of the month.

In 1973…post-frontal heavy snowfall totaled 7.6 inches at Stapleton International Airport where northeast winds gusting to 37 mph caused some blowing snow.

In 1990…strong downslope winds raked the eastern foothills and most of metro Denver. A wind gust to 87 mph was recorded at Rollinsville with wind gusts to 58 mph in Arvada and 55 mph in Lakewood. West winds gusted to 48 mph at Stapleton International Airport on the 2nd.

In 1997…heavy snow fell in the foothills. Conifer received 10 inches of new snow. Snowfall totaled only 2.4 inches at the site of the former Stapleton International Airport on the 1st…2nd…and 3rd. North winds gusted to 24 mph at Denver International Airport on the 2nd.

2-4

In 1909…post-frontal snowfall totaled 6.1 inches in downtown Denver. Most of the snow…5.9 inches…fell between 6:00 pm on the 2nd and 6:00 pm on the 3rd. North winds were sustained to 18 mph on both the 2nd and 3rd.

2-17

In 1939…more than 2 weeks of unseasonably warm weather made the month the 3rd warmest on record. Seven daily temperature records were set…including the all-time record high temperature for the month of 79 degrees on the 5th. Daytime highs were balmy with 14 days in the 60’s and 70’s. Low temperatures dipped to freezing or below on only 5 days. The period was dry with only a trace of snow on the 12th.

3

In 1977…high winds continued in Boulder and were clocked from 74 to 90 mph…causing only minor damage. Northwest winds gusted to 33 mph at Stapleton International Airport where the strong Chinook winds warmed the temperature to a high of 63 degrees.

In 1985…wind gusts to 78 mph were clocked at Table Mesa in Boulder. Winds gusted to 70 mph at Echo Lake west of Denver.

In 2011…another round of snow developed in and near the Front Range foothills. The heaviest snowfall occurred in the foothills of Boulder and northern Jefferson counties. Storm totals included: 13 inches…7 miles southwest of Boulder; 10.5 inches…4 miles east-northeast of Nederland; 10 inches at Genesee; 9.5 inches…4 miles west-northwest of Boulder; 9 inches at Gross Reservoir and 4 miles east of Pinecliffe. Around the urban corridor…storm totals ranged from 3 to 8 inches…heaviest in and around Boulder. At Denver International Airport…3 inches of snow fell.

3-4

In 1968…strong Chinook winds in Boulder gusting to 52 mph downtown caused 7 thousand dollars in damage. Flying debris damaged cars…houses…and other property in Boulder. West winds gusted to 49 mph late on the 3rd and to 45 mph on the 4th at Stapleton International Airport where the temperature climbed to a high of 60 degrees on the 4th.

In 1970…strong winds whistled through Boulder. Sustained winds of 40 mph with gusts to 70 mph were recorded at the National Bureau of Standards in Boulder. Wind gusts to 50 mph occurred in downtown Denver. No damage was reported. On the 3rd…northwest winds gusted to 40 mph at Stapleton International Airport where the Chinook winds warmed the temperature to a high of 66 degrees on the 4th.

In 1999…heavy snow fell over the foothills and metro Denver. The heaviest snowfall occurred in the foothills south of I-70 and near the Palmer Divide. Snowfall totals included: 25 inches near Tiny Town; 18 inches at Conifer; 15 inches near Evergreen; 14 inches at Chief Hosa…8 miles west of Castle Rock…and near Blackhawk; 12 inches at Pine Junction and 8 miles south of Sedalia; 11 inches atop Floyd Hill and in Roxborough; and 10 inches at Castle Rock. Around metro Denver…snowfall totals included: 10 inches at Highlands Ranch…9 inches at Parker…and 8 inches in Aurora and Wheat Ridge. Elsewhere around the metro area…snowfall generally ranged from 3 to 5 inches. Only 3.2 inches of snow fell at the site of the former Stapleton International Airport. North winds gusted to 32 mph at Denver International Airport on the 3rd.

In 2007…high winds developed in and near the Front Range foothills. Peak wind reports included: 88 mph atop Niwot Ridge; 87 mph atop Mines Peak; 80 mph…3 miles southeast of Jamestown; 78 mph at Longmont; 74 mph at Table Mesa. A few power outages occurred in Longmont as broken branches downed power lines. Northwest winds gusted to 38 mph at Denver International Airport on the 4th.

In 2013…a storm system brought heavy snow to parts of the Front Range Foothills. Storm totals included: 12 inches.. 7 miles west-southwest of Evergreen; 10.5 inches…3 miles north of Bailey; 9.5 inches…3 miles west of Jamestown and 5 miles northeast of Ward; 9 inches in Bailey…8.5 inches… 3 miles north of Conifer.

Continue reading December 1 to December 7: This Week in Denver Weather History