Thornton, Colorado, USA
UpdatedTue, 26-Oct-2021 7:35pm MDT 


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Tuesday starts out warm, cold front later to cool it down, bring chance of showers

Tuesday, October 26th, 2021 5:04am MDT

We will start off the day relatively mild but by the latter half of the day, the picture changes. A cold front will be pushing through and with it, cooler temps, breezy winds and some showers.

Sunrise will see partly clear skies with relatively warm temperatures. Cloud cover will be increasing from mid-morning through the afternoon as a front pushes through. With the front, winds will be picking up steadily and be breezy for much of the day.

Temperatures will top out near the 70 degree mark right around noon but then start to drop. Scattered showers will develop after noon and last into the evening. Unfortunately, we are not expecting much out of these.

Tonight, cloud cover will begin to ease but breezy winds will continue for much of the night. Overnight lows will be in the mid-30s.

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Monday to offer up mild temperatures but with some breezy winds

Monday, October 25th, 2021 5:12am MDT

Thornton’s workweek starts off in pretty descent fashion. We will enjoy very mild temperatures although there will be some wind that will bring along increased fire danger.

Partly clear skies start us off then by mid to late morning, the cloud cover will ease. High temperatures today will top out in the mid to upper 70s. Winds will be picking up this afternoon then settle down in the evening.

Those winds coupled with low humidity and dry fuels have prompted a Red Flag Warning to be issued. Please be very careful.

Tonight, skies will be largely clear with some breezy winds after midnight. Overnight lows will be in the mid-40s. Keep an eye on the temps and wind here.

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October 2021 top shots: Monthly photo slideshow

Sunday, October 24th, 2021 6:01pm MDT
An old homestead among fall colors in Park County. (Bill Hutchinson)

An old homestead among fall colors in Park County. (Bill Hutchinson)

October in Thornton can bring a wide variety of weather conditions, perfect for the photographer in all of us.

The month brings the changing of the colors at Colorado’s lower elevations and it is also is typically when we see our first freeze and first snow.

Couple those facts with our usual widely varying landscapes and wildlife and we have a month that is sure to bring in plenty of photo opportunities.

  • Slideshow updated October 24, 2021
  • 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!

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October 24 to October 30: This week in Denver weather history

Sunday, October 24th, 2021 5:14am MDT

This Week in Denver Weather History

This year Denver is still waiting for its first snow and we have already passed the average date we see it (October 19).  That however isn’t always the case and October can bring monster snowstorms as we see in our look back at this week in Denver weather history.

From the National Weather Service:


In 1887…the first measurable snowfall of the season totaled 3.1 inches.  North winds to 20 mph were recorded on the 23rd.  This was the only measurable snow of the month.

In 1932…post-frontal snowfall from the late evening of the 23rd continued through the late afternoon of the 24th and totaled 6.2 inches.  Southeast winds were sustained to 25 mph with gusts to 26 mph on the 23rd.  Temperatures cooled from a high of 68 degrees on the 23rd to a low of 25 degrees on the 24th…the coldest reading of the month that year.  Many trees that had not shed their leaves became heavily laden by the wet snow.  Many branches were broken… And a few trees toppled under the weight of the snow.  The landscape became one of rare beauty.


In 1956…southwest winds gusted to 56 mph and produced some blowing dust at Stapleton Airport.  A cold front produced a thunderstorm with 1/8 inch hail.  Rain later changed to snow.  Precipitation totaled only 0.11 inch and snowfall only 0.3 inch.

In 1973…strong winds raked the eastern foothills…causing damage in Boulder and Jefferson counties.  The heaviest damage occurred in the Boulder area where 20 to 25 mobile homes were hit…some power and telephone lines were blown down…and a store was damaged.  A wind gust to 76 mph was recorded in Boulder at the National Bureau of Standards. Northwest winds gusted to 46 mph at Stapleton International Airport.


In 1921…rainfall totaled 0.35 inch overnight behind an apparent cold front.  North winds were sustained to 40 mph with gusts to 46 mph on the 25th.  Temperatures plunged from a high of 73 degrees on the 24th to a low of 39 degrees on the 25th.

In 1923…rain overnight changed to snow during the morning. The heavy snowfall accumulated to 12.0 inches before ending on the morning of the 25th.  Post-frontal north winds were sustained to 22 mph with gusts to 23 mph on the 24th.

In 1997…one of the worst and deadliest blizzards of the decade developed over eastern Colorado as deep east to northeast flow associated with a vigorous upper level low pressure system over the Four Corners…combined with a strong arctic air mass over the central Great Plains. Snowfall totals across metro Denver ranged from 14 to 31 inches.  The heaviest snowfall occurred in the foothills west and southwest of Denver where 2 to 4 feet of snow were measured.  Sustained winds to 40 mph with gusts as high as 60 mph produced zero visibilities and extremely cold wind chill temperatures from 25 below to 40 below zero.  Winds whipped the snow into drifts 4 to 10 feet deep.  Several major and interstate highways were closed as travel became impossible.  Red Cross shelters were set up for hundreds of travelers who became stranded when they had to abandon their vehicles.  Four people died in northeastern Colorado as a result of the blizzard.  None of the deaths were in metro Denver.  At Denver International Airport…4 thousand travelers were stranded when the airport was forced to shut down.  At least 120 cars were abandoned along Pena Blvd….the only arterial leading into and out of DIA.  The blizzard cost air carriers at least 20 million dollars.  Thousands of cattle died in the storm over northeastern Colorado…resulting in losses totaling 1.5 million dollars.  Some of the more impressive snowfall totals included:  51 inches at Coal Creek Canyon; 48 inches at Silver Spruce Ranch…near Ward; 42 inches at Intercanyon…in the foothills southwest of Denver; 37 inches at Sedalia; 35 inches at Aspen Springs and Conifer in the foothills west of Denver; 31 inches at Eldorado Springs… Southeast Aurora…and Englewood; and 30 inches on Table Mesa in Boulder.  Snowfall totaled 21.9 inches at the site of the former Stapleton International Airport…setting a new 24-hour snowfall record of 19.1 inches for the month. Snowfall totaled only 14 inches at Denver International Airport where north winds gusted to 39 mph on the 24th. High temperature of only 21 degrees on the 25th equaled the record low maximum for the date first set in 1873. Low temperature of only 3 degrees on the 26th set a new record minimum for the date.


In 1925…a vigorous cold front produced north winds sustained to 42 mph with gusts to 52 mph.  Post-frontal snowfall was only 0.4 inch during the late afternoon and early evening.

In 1959…northwest winds gusted to 55 mph at Stapleton Airport.

In 1997…the high temperature warmed to only 21 degrees…the record low maximum for the month.  The same temperature also occurred on October 30…1991.


In 1996…4 to 6 inches of snow fell in the foothills west of Denver.  Only 1.5 inches of snowfall were measured at the site of the former Stapleton International Airport on the 26th.  This was the only measurable snow of the month at the site.  The snowfall produced icy and snowpacked highways…which resulted in a 50-to 60-car pileup on I-25 south of metro Denver.  West winds gusted to 33 mph at Denver International Airport.

In 2006…a winter storm brought heavy snowfall to metro Denver and the eastern foothills.  Total snowfall ranged from 12 to 22 inches over the higher terrain and 6 to 12 inches across metro Denver.  Northerly winds at sustained speeds of 20 to 30 mph with gusts as high as 47 mph at Denver International Airport whipped the snow into drifts 3 to 4 feet deep.  Many tree limbs snapped under the weight of the heavy…wet snow which also downed power lines… Leaving thousands of residents without power.  Storm total snowfall included:  25 inches near Aspen Springs…conifer… And Evergreen; 23.5 inches near Rollinsville; 23 inches in Idaho Springs; 22.5 inches near Blackhawk; 21.5 inches near Bailey; 19 inches near Bergen Park; 18 inches near Aspen Springs…Genesee…and Jamestown; 17 inches southwest of Boulder; 16 inches in Evergreen; and 15 inches near Georgetown and Perry Park.  Snowfall totaled 5.3 inches in the Denver Stapleton area.  At Denver International Airport…rain…including a thunderstorm…changed to snow on the evening of the 25th after a high temperature of 70 degrees.

In 2010…a storm system brought heavy snow to the mountains west of Denver. Storm totals included: 24 inches at the Eisenhower Tunnel…18 inches at Loveland Ski Area; with 16 inches at Arapahoe Basin.


In 1897…a major storm dumped 13.5 inches of snowfall over downtown Denver.  Rain changed to snow during the evening of the 25th and continued through mid-morning of the 27th. Most of the snow…12.0 inches…fell on the 26th when north winds were sustained to 36 mph and gusts were as high as 46 mph.  Temperatures during the storm were in the 20’s and lower 30’s.  Precipitation (rain and melted snow) totaled 1.21 inches.


In 1995…winds gusting from 100 to near 110 mph pounded the foothills northwest of Denver.  At Nederland winds gusted to 100 mph and to 70 mph in Coal Creek Canyon.  Atop Squaw Mountain west of Denver wind gusts to 108 mph were recorded.  The strong winds downed some trees and caused power outages.  West-northwest winds gusted to 47 mph at Denver International Airport.

In 2010…very strong winds during the day knocked down power lines in parts of Boulder. The downed electrical lines sparked a small brush fire near Columbine Elementary School. Strong wind gusts also damaged the tennis bubble at the Millennium Harvest House. In Northglenn. a tree was knocked down and caused minor damage to a mini-van parked nearby. Peak wind gusts included: 70 mph at Berthoud…67 mph at Rocky Mountain Metropolitan Airport in Broomfield… 63 mph at the Rocky Flats National Wind Technology Center and 59 mph at the NCAR Mesa Laboratory…3 miles southwest of Boulder. West winds gusted to 43 mph at Denver International Airport.

In 2011…a powerful early season storm brought heavy snow to the Front Range and adjacent plains. The heavy…wet snow caused extensive downed large branches and in some cases…entire trees. Massive power outages occurred from Fort Collins and Greeley south to Denver and the surrounding metro area. Most of the trees still had their leaves…which helped to catch snow and down trees under the weight of the moisture laden snow. Nearly two hundred thousand utility customers along the Front Range were without heat and electricity for several hours. The Red Cross opened four temporary shelters overnight until the power could be restored. The outages also forced the closure of the Boulder Criminal Justice Center the following day. The fallen trees and branches also caused extensive property damage to roofs and automobiles. In the Front Range mountains and foothills…storm totals included 19.8 inches…3 miles west of Jamestown; 18 inches…5 miles west of Copper; 13 inches…3 miles north of Blackhawk and 3 miles south of Evergreen…4 miles east-northeast of Nederland and Lake Eldora; 12 inches at Berthoud SNOTEL. Across the Urban Corridor storm totals included: 11.5 inches in Boulder; 9.5 inches at the National Weather Service in Boulder; 9 inches…1 mile southwest of Westminster; 8.5 inches in Broomfield… Denver International Airport…Frederick and Louisville; 8 inches in Aurora…7 inches in Watkins; with 6 inches in Arvada.

» Click here to read the rest of October 24 to October 30: This week in Denver weather history

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Winter Weather Preparedness Week recap

Saturday, October 23rd, 2021 4:30am MDT
Winter Weather Preparedness Week concludes. Are you ready for winter?

Winter Weather Preparedness Week concludes. Are you ready for winter?

As we have talked about this week, winter weather can be dangerous and downright deadly.  However, being prepared helps to ensure that you and your family remain safe when the snow starts to fly or other winter weather conditions occur.

It is very easy to ignore the dangers of weather – no matter the season – and find yourself saying, “I wish I would have….” Now is the time to think about how you can prepare for these conditions, before it is too late and you find yourself wishing you had.

In this sixth and final message in a series on Winter Weather Preparedness from the National Weather Service, ThorntonWeather.com reviews the topics we covered this week and directs you to the previous articles and other resources to help you get ready.

600 AM MDT SAT OCT 23 2021

Enjoy the great outdoors in Colorado this winter season, but watch the weather.

The National Weather Service issues a variety of winter weather, outlooks, watches, warnings, and advisories, covered earlier during this Winter Weather Preparedness Week.  Safety tips were also passed along.

» Click here to read the rest of Winter Weather Preparedness Week recap

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Thornton’s weekend starts off warm then cool down closer to normal

Friday, October 22nd, 2021 4:56am MDT

The three day period starts on the upside with mild conditions but then a passing system will serve to cool us down.

For Friday, mostly sunny to sunny skies will be above. Temperatures will be pleasant with highs in the low 70s. Tonight, partly cloudy skies will be above with lows in the upper 30s.

Saturday, a system passes through that will lead to increased cloud cover and cooler mercury readings. Look for highs in the mid-60s under mostly cloudy skies. Saturday night, mostly cloudy skies will be above with overnight lows around 40 degrees. There is just a slight chance for an overnight shower of rain.

Sunday sees the sun return but temperatures will be cooler. Highs will be in the low to mid-60s under sunny skies.

Have a great weekend!

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Avalanche safety – Be prepared or die

Friday, October 22nd, 2021 3:40am MDT
Avalanches claim lives every year in Colorado. Before you head to the mountains, be sure you are prepared! (Wikimedia Commons)

Avalanches claim lives every year in Colorado. Before you head to the mountains, be sure you are prepared! (Wikimedia Commons)

As snow starts to fall, many Coloradoans and out of state visitors will take advantage of it and head to the mountains for a variety of outdoor activities.  Whether skiing, snowshoeing, or hiking, anyone who spends time outdoors in the high country needs to be aware of the danger avalanches present.  On average six people die in Colorado every year from avalanches and being prepared is an essential survival skill.

In this fifth in a series on Winter Weather Preparedness from the National Weather Service, ThorntonWeather.com helps you understand avalanches, where they occur, how to protect yourself and where to go for more information.  If you are headed to the high country, be sure to check out our Avalanche Information & Forecast page.

600 AM MDT FRI OCT 22 2021

Avalanches – Are you prepared?

Thousands of avalanches occur each winter in the mountains of Colorado. With the enormous popularity of winter sports in Colorado, this poses a risk to skiers, snowboarders, snowmobilers, and people traveling in the backcountry. On average 6 people die in Avalanches in the state of Colorado every year. Anyone who travels into the high country in the winter should be prepared for avalanches And know how to avoid them.

The most important thing to know is how to get information on current avalanche conditions. Check the Colorado Avalanche Information Center website at http://avalanche.state.co.us/ for the current avalanche forecast and the National Weather Service website http://www.weather.gov for the current weather forecast in your area. Knowing the current and future conditions will help you make good decisions in the backcountry.

A little information about avalanche safety can go a long way. Most avalanches occur during or just after snowstorms on a slopes between 30 to 45 degrees. A significant snowfall may result in an unstable snowpack. By waiting at least 36 hours after a big snow or wind storm before you go into the mountains the Snow may become more stable and less likely to avalanche. If you stay in valleys away from avalanche chutes, in stands of dense trees, or on gentle slopes you can decrease the risk of being caught in an avalanche.

If you are a skier or snowboarder at a commercial ski area the risk from avalanches is lower than in the backcountry. Ski patrols work to reduce the chance of an avalanche on open slopes. Respect the rules of the ski area, stay on open slopes, and do not stray out of bounds or into closed areas. The avalanche risk is higher outside of the ski area boundaries.

If you want to enjoy the great outdoors in areas prone to avalanches…You can reduce the danger by following a few simple rules:

  • Check the current avalanche forecast to get information on current and forecast avalanche conditions. Also check the latest weather forecast to see if conditions are likely to change while you are in the backcountry.
  • Never travel alone. Always have one or more companions. Even small avalanches can be fatal. If you are alone and get trapped, you may not be found until spring.
  • If crossing a slope that may be prone to avalanches, do it one person at a time. You want to minimize the impact on your party if an avalanche is accidentally released.
  • In avalanche country, all members of your party should carry avalanche rescue equipment including an avalanche beacon, shovel and probe pole. This increases your chances of a successful rescue and finding your friends alive.

Avalanche conditions in Colorado are monitored and forecasted by the Colorado Avalanche Information Center, CAIC. You can get more information on avalanches, avalanche forecasts, avalanchesafety and request a safety class from CAIC. Go to their website…Http://www.colorado.gov/avalanche or call the center at 303-499-9650.

Winter Weather Preparedness Week continues through Saturday. Now is the time to get prepared for winter so you can safely enjoy the outdoors and travel safely when the snow flies.

Avalanche Safety Tips

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Thursday to offer temps a bit above normal, increased clouds

Thursday, October 21st, 2021 4:56am MDT

Not too shabby of a day ahead for Thornton. Temperatures will be at or a bit above average but we will see some clouds above.

Mostly clear skies start us off but then an increase in moisture aloft will lead to partly sunny skies for much of the day. Cloud cover will ease in the late afternoon. Overall conditions will be calm and dry. Highs today will top out in the mid-60s.

Tonight, skies will clear and lows will be in the mid-30s.

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Life threatening winter weather – Wind chill, frostbite and hypothermia

Thursday, October 21st, 2021 4:00am MDT
Wind chill is a life threatening weather danger that is often ignored or underestimated. (AP Photo)

Wind chill is a life threatening weather danger that is often ignored or underestimated.

Winter weather can not only be trying on the mind and soul, it also presents very real dangers to the human body.  Extreme wind chills can be deadly and bring on the outset of frostbite and hypothermia.  Here in Colorado, all residents should be aware of these hazards and be prepared to deal with them.

In this fourth in a series on Winter Weather Preparedness from the National Weather Service, ThorntonWeather.com helps you understand wind chill and how to protect yourself from frostbite and hypothermia.

600 AM MDT THU OCT 21 2021

Extreme wind chill – Potentially life-threatening and often overlooked

Extremely cold air comes every winter in at least part of the country and affects millions of people across the United States. The arctic air, combined with brisk winds, can lead to dangerously cold wind chill values. The Wind Chill Index helps you determine when dangerous conditions develop that could lead to frostbite or hypothermia. It takes into account heat loss from the human body to its surroundings during cold and windy weather. The calculation utilizes wind speed in miles per hour and temperature in degrees Fahrenheit. For example, a temperature of minus 5 degrees occurring with a 20 mph wind gives a wind chill near minus 30 degrees. This means that your body will lose heat at the same rate as it would if the air temperature were minus 30 degrees with no wind. Wind Chill values near minus 25 degrees mean that frostbite is possible within 15 minutes.

  • How does the wind affect wind chill?  See the chart below.

Frostbite is the freezing of skin and the body tissue just beneath it. It first affects exposed body tissue where blood circulation may be limited such as your fingers, toes, nose and ears. To minimize frostbite, make sure all body parts are well covered. When frostbite starts, feeling is lost in the affected area and the frozen tissue will take on a white or pale appearance. If you suspect you are experiencing frostbite, hold the frostbitten area closely against warm skin to return blood flow and warmth to the affected area.

Hypothermia is a dangerously low body temperature and is the most common winter weather killer. When you hear of a hiker, climber, hunter or a stranded traveler perishing from cold weather exposure, hypothermia was the cause. Most people are surprised to learn that hypothermia deaths can occur with temperatures between 30 and 50 degrees. If you or your clothing are wet, then hypothermia becomes even more likely.

Warning signs of hypothermia include uncontrollable shivering, memory loss, disorientation, slurred speech and drowsiness. Immediate medical attention should be given to victims suspected of suffering from hypothermia. If no help is available, the victim should be warmed slowly with warm liquids along with dry clothing and blankets.

The National Weather Service will issue wind chill advisories and warnings when a deadly combination of wind and cold air threaten. A Wind Chill Warning will be issued for the following wind chill temperatures:

  • Mountains…minus 35 degrees Fahrenheit or colder.
  • Lower Elevations…minus 25 degrees Fahrenheit or colder.

When cold weather threatens, follow these tips for survival:

  • Stay dry, wet clothing results in much faster heat loss from your body. Wear waterproof insulated boots.
  • Stay covered, wear mittens or gloves and wear a hat. At least half of your body heat is lost if your head is not covered.
  • Dress layered, trapped air between loose fitting clothing helps to insulate.
  • Stay informed, have a portable NOAA weather radio nearby to keep you up-to-date with the latest forecasts and warnings. Use wind chill temperatures to guide you in dressing properly for the outdoors. On very cold days, minimize your exposure to the outdoors if possible.

Winter Weather - Extreme Cold Safety

Winter Weather - Signs of Hypothermia

Wind Chill Chart

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Cool, calm, dry conditions for Thornton’s Wednesday

Wednesday, October 20th, 2021 4:55am MDT

A pretty typical day for this time of year. We will enjoy lots of sun and cool temperatures right near average.

Sunny skies will be the general rule throughout the day with only a cloud here and there. Winds will be light, conditions calm and dry. Look for high temperatures today right near the average high for the date of 64 degrees.

Tonight, skies remain mostly clear with overnight lows in the mid-30s.

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