Thornton, Colorado, USA
UpdatedTue, 22-Oct-2019 11:00am MDT 


ThorntonWeather.com on Twitter

ThorntonWeather.com on Facebook


Weather Geek Stuff - weathergeekstuff.com

Rocky Mountain Weather Network

Tony's Takes Photography


Recent News and Posts

A few clouds but very warm temperatures highlight Thornton’s Wednesday weather

Wednesday, October 16th, 2019 4:59am MDT

After yesterday’s cool down, we will rebound nicely today. While there will be some clouds, they will do little to inhibit temperatures that will be well above normal.

Mostly sunny skies will be above throughout the day as some high level moisture will offer up some clouds.

We start out with chilly temperatures but will experience steady warming as we head toward a high in the upper 70s. The average high for today’s date is 64 degrees.

Tonight, mostly clear skies will be above with low temperatures around 40 degrees.

Join the Discussion - Post your commentJoin the Discussion!

Winter weather – What does that weather warning mean?

Tuesday, October 15th, 2019 4:49am MDT
You have seen and heard the warnings but do you know what they really mean?

You have seen and heard the warnings but do you know what they really mean?

We all are familiar with the crawls on the TV screen or the announcements on the radio for winter weather advisories such as Winter Storm Watch, Blizzard Warning, Freeze Warning and more. But, how many of us really know what those mean? There is very specific criteria the National Weather Service follows in issuing these watches and warnings and there are important differences between all of them.

In this second in a series on Winter Weather Preparedness from the National Weather Service, ThorntonWeather.com helps you understand what all of these mean so you can be better prepared.

600 AM TUE OCT 15 2019

From the National Weather Service:

What does that warning mean?

When a warning is issued during the winter season, will you know what it means, and will you know how to respond? During this Colorado Winter Weather Preparedness Week, please become familiar with our list of potentially life-saving winter weather products.

This statement contains warning and advisory criteria for Colorado east of the continental divide. Criteria west of the divide will be provided today in a separate issuance by the Grand Junction forecast office.


A Hazardous Weather Outlook is issued daily by each National Weather Service office serving Colorado. The outlook provides information on potentially hazardous weather out to 7 days into the future. Also, the Weather Story, a graphic of expected hazardous weather, is posted daily on National Weather Service web sites serving Colorado.

Watches and Warnings

A Winter Storm Watch is issued when hazardous winter storm conditions are possible within the next 3 to 4 days, but the timing, intensity, or occurrence may still be uncertain.

In contrast, a Winter Storm Warning is issued for potentially life-threatening winter storm conditions, such as heavy snowfall or a combination of snowfall and blowing snow, which are likely to occur within the next 1 to 2 days.

Warning criteria for heavy snow is defined by the following amounts.

  • For the mountains – 8 inches of snow accumulation in 12 hours or 12 or more inches in 24 hours.
  • For the lower elevations – 6 inches of snow accumulation in 12 hours or 8 or more inches in 24 hours.

A Blizzard Warning is issued when the following conditions are expected to occur for at least 3 hours:

  • Sustained winds of 35 mph or greater.
  • Considerable falling and/or drifting snow lowering
  • Visibilities to less than a quarter mile.

A high wind warning is issued:

  • Mountains…sustained winds 50 mph or more, or gusts of at least 75 mph.
  • Lower Elevations…sustained winds of 40 mph or more, or gusts of at least 58 mph

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.

A Dust Storm Warning will be issued for the following conditions:

  • Visibility reduced to 1/4 mile or less in blowing dust and sustained winds of 25 mph or greater for at least one hour.


Advisories for winter weather are issued for potentially hazardous conditions which are considered more of a nuisance than a life-threatening situation. However, if caution is not taken the advisory events could become life-threatening

This week is Winter Weather Preparedness Week in Colorado. Public information statements will be issued throughout the week to give safety information and help you know how to respond when winter weather threatens.

Winter weather watches and advisories.

Join the Discussion - Post your commentJoin the Discussion!

Cool, calm weather conditions for Thornton’s Tuesday

Tuesday, October 15th, 2019 4:47am MDT

With the passing of a cold front late yesterday, we will see things cool down a good bit today. We will still have a good dose of sun above and conditions remain calm.

The day starts out with just a few clouds but sunny skies will be the rule for the majority of the day. Winds will be light and out of the east, conditions calm and dry. High temperatures today will top out in the low 60s.

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

Join the Discussion - Post your commentJoin the Discussion!

Winter travel safety – Ensure you and your vehicle are ready

Monday, October 14th, 2019 5:05am MDT
Are you and your vehicle ready for the winter weather ahead?

Are you and your vehicle ready for the winter weather ahead?

Before hitting the road, Coloradans need to ensure that they and their vehicles are prepared should inclement weather strike.

ThorntonWeather.com presents the first in a series from the National Weather Service (NWS) as part of Winter Weather Preparedness Week has declared by Colorado Governor John Hickenlooper.  Check back throughout the week for more winter preparedness stories.

Today’s message from the NWS highlights the importance of having a proper emergency kit in your vehicle and should the worst-case scenario occur where you get stuck, what you should do to survive.

601 AM MDT MON OCT 14 2019

Winter Travel Safety

Winter Weather Preparedness Week continues through Saturday.  Preparedness is a big part of this campaign. Before winter weather arrives in earnest, it is highly recommended that you prepare your car or truck for winter travel.

A well equipped vehicle has adequate tires, tire chains, tow rope, sand or cat litter for traction, shovel, tool kit, windshield scraper and brush, battery cables, first aid kit, flashlight, extra batteries, blankets and/or sleeping bags, extra clothing, candles, water-proof matches, high calorie packaged food for quick energy and an empty can to melt snow for drinking.

The best way to prevent treacherous winter travel is to avoid it. This can be done by staying informed about current weather and road conditions as well as the latest weather forecasts. Information on road conditions in Colorado is available on the web at www.cotrip.org or from the toll free number 1-877-315-7623. When calling from anywhere in Colorado, dialing 511 will also access the Colorado road reports. Additionally, a free smartphone application, CDOT Mobile, is available.

If you should become stranded during a winter storm, stay with your vehicle an d do not panic. If accompanied by others, take turns sleeping. Run the motor every hour for about ten minutes to maintain warmth, but keep windows open a little to prevent the buildup of carbon monoxide. Make sure the exhaust pipe is not blocked. Keep the car visible with brightly colored cloths tied to the side view mirrors, door handles, or external antenna. At night, turn on the dome light when running the engine. Exercise periodically by vigorously moving arms, legs, toes and fingers.

In the mountains, avalanches become a possibility in the winter, especially below steep slopes. Avalanches occasionally come down across roads, with little or no warning. However, avalanche control work is performed on many avalanche prone roads in Colorado, making the roads safer to travel. Caution is advised when traveling along avalanche prone roads, especially during and shortly after a heavy snowstorm or during periods of rapid snowmelt.

Very strong downslope winds occur at times mainly along the front range of Colorado. These Chinook and Bora winds can have gusts exceeding 100 mph. Persons traveling in light weight or high profile vehicles should avoid travel during these strong wind events especially on north-south oriented roads.

Roads which appear to be clear in the wintertime may actually be coated with a thin layer of ice, commonly known as black ice. This nearly invisible ice layer can cause you to rapidly lose control of your vehicle. Black ice is most common during the nighttime hours. If you detect black ice you should reduce your speed.

Please follow these winter travel safety recommendations which could save your life.

Winter Weather Awareness Week - Winter Travel Safety. (National Weather Service)

Winter Weather Awareness Week – Winter Travel Safety. (National Weather Service)


Join the Discussion - Post your commentJoin the Discussion!

Thornton’s workweek starts off with unseasonably warm temps, calm conditions

Monday, October 14th, 2019 5:02am MDT

We are starting off the week in fine fashion. Monday will offer up lots of sun and temperatures a good ways above normal.

The day starts with just a few clouds but not many and most of those will soon clear leading to sunny skies. High temperatures today will top out in the mid-70s, a good ways above the average high for the date of 66 degrees. Overall conditions are going to be calm and dry.

This evening, a cold front is going to move through and that will lead to low tonight close to freezing.

Tomorrow’s highs will be a good bit cooler but conditions will remain dry.

Join the Discussion - Post your commentJoin the Discussion!

October 13 to October 19: This Week in Denver Weather History

Sunday, October 13th, 2019 10:52am MDT
This week in Denver weather history

October 13 to October 19: This Week in Denver Weather History

Certainly snow begins to enter the equation as we get further into the season and our look back at Denver weather history for the week shows many such notable events. Others including damaging winds and even a tornado and monstrous hail storm.

From the National Weather Service:


In 1892…apparent post-frontal rainfall totaled 3.33 inches in downtown Denver over the 3 days. A trace of snow on the 12th melted as it fell. Rainfall of 2.58 inches on the 12th into the 13th was the greatest 24-hour precipitation ever recorded during the month of October. Northwest winds were sustained to 48 mph with gusts as high as 55 mph on the 12th.


In 2001…overnight peak wind gusts to 82 mph and 70 mph were measured atop Niwot Ridge and Squaw Mountain… Respectively.


In 1969…record breaking extremely cold temperatures for so early in the season occurred. The high temperature of 26 degrees on the 13th was two degrees lower than the previous record minimum temperature of 28 degrees for the date set in 1885. The high temperature of 24 degrees on the 12th exceeded the record low temperature (22 degrees set in 1885) for the date by only 2 degrees. In addition… 3 new record low temperatures for the dates were set. The low temperature dipped to 10 degrees on the 12th breaking the old record (22 degrees in 1885) by 12 degrees. On the 13th the mercury plunged to a low of 3 degrees breaking the old record (28 degrees in 1885) by 25 degrees. On the 14th the temperature reached a minimum of 4 degrees breaking the old record (25 degrees in 1966) by 21 degrees.


In 1990…strong downslope winds stirred up clouds of dust and gravel…rattled windows…and stripped autumn-colored leaves from trees in Boulder. A wind gust to 78 mph was clocked in southwest Boulder…while a 96 mph gust was recorded in northwest Boulder. West winds gusted to only 36 mph at Stapleton International Airport.


In 1910…light smoke from nearby forest fires drifted over the city.

In 1966…the first measurable snow of the season caused widespread damage to trees and shrubs. The heavy wet snow totaled 6.9 inches at Stapleton International Airport where north-northwest winds sustained at 20 to 25 mph and gusting to 45 mph caused much blowing and drifting snow. South and east of Denver…up to a foot of snow fell. Heavy wet snow accumulations followed by freezing temperatures and strong winds resulted in extensive damage to trees…cars… And utility lines by falling limbs. A woman was killed by a falling snow laden tree limb in Denver. Several other people received minor injuries from falling tree limbs.

In 1987…rain drenched metro Denver. The South Platte Canyon area southwest of Denver received the most with 1.11 inches at Kassler and 1.49 inches upstream at Strontia Springs. At Stapleton International Airport…0.62 inch of rain was measured…northwest winds gusted to 29 mph…and thunder was heard.

In 2007…a new 24-hour record of 2.65 inches of precipitation was set at Denver International Airport for the month of October; breaking the previous record of 2.58 inches set in 1892.


In 1873…smoke from several large forest fires in the mountains made the air very hazy in the city.


In 1952…the first measurable snowfall of the season left 1.2 inches of snow at Stapleton Airport. North winds gusted to 38 mph.

In 1974…rain changed to snow early in the day…but snowfall totaled only 1.0 inch at Stapleton International Airport where northeast winds gusted to 20 mph.


In 1871…a terrible wind occurred during a snow storm in the foothills above Boulder. Damage was minor.

In 1878…high winds reached sustained speeds of 60 mph at times.

In 1911…post-frontal northwest winds were sustained to 41 mph with gusts to 43 mph.

In 1948…strong winds struck the Boulder area. Winds averaged 50 mph at Valmont just east of Boulder. Wind gusts in excess of 60 mph were recorded at the Boulder airport. Wind gusts to 40 mph briefly reduced the visibility to 1 1/2 miles in blowing dust at Stapleton Airport.

In 1980…a rare October tornado touched down in Boulder… Damaging a vocational training building and throwing three nearby cars together damaging them extensively. A mile and half away several camper vehicles were thrown 200 feet. The storm also produced 1 inch diameter hail in the Boulder area.


In 1928…a thunderstorm produced hail shortly after midnight on the 15th. Rain changed to snow by evening. Through the afternoon of the 16th…the heavy snowfall totaled 7.3 inches in the city. North winds were sustained to 23 mph on the 15th.

In 1984…the heaviest October snowstorm in several years hit eastern Colorado with a vengeance. The storm was known as the “Bronco Blizzard” since it occurred during a nationally televised Monday Night Football game in Denver. One to two feet of snow fell near the foothills in west metro Denver with 2 to 3 feet in the foothills. Wind gusts up to 55 mph whipped the snow into drifts as high as 4 feet. The storm closed schools…roads…and airports. I-70 was closed both east and west of Denver. I-25 was closed south to Colorado Springs. Flights were delayed for several hours at Stapleton International Airport. Power outages were widespread. Snowfall totaled 9.2 inches at Stapleton International Airport where north winds gusting as high as 40 mph caused frequent surface visibilities of 1/4 to 1/2 mile in moderate to heavy snow and blowing snow overnight. The high temperature of only 35 degrees on the 15th was a record low maximum for the date.

» Click here to read the rest of October 13 to October 19: This Week in Denver Weather History

Join the Discussion - Post your commentJoin the Discussion!

Colorado Winter Weather Preparedness Week introduction

Sunday, October 13th, 2019 5:30am MDT
Don't be caught off guard by winter weather! Remember the Christmas Eve Blizzard of 1982? Be prepared!

Don’t be caught off guard by winter weather! Remember the Christmas Eve Blizzard of 1982? Be prepared!

Winter weather in Colorado can be an inconvenience but more than that it can be deadly.  Emergency preparedness for major winter storms – as well as for other types of severe weather – is an important part of living in a state where conditions can change wildly from one moment to the next.

To help raise awareness of the need to be prepared for these occasions, the week of October 14th to October 20th has been proclaimed Winter Weather Preparedness Week in Colorado.

The National Weather Service will be issuing Public Information Statements each day this week to highlight the dangers of winter weather and how best to be prepared.  ThorntonWeather.com will be posting these important messages here to help you be prepared.  Please take the time to read and heed these messages – your life and the lives of your loved ones could depend on it.

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

From the National Weather Service:

Public Information Statement
National Weather Service
Grand Junction CO

..Winter Weather Preparedness Week in Colorado…

The week of October 13th through October 19th is Winter Weather Preparedness Week in Colorado. This is an excellent time for all individuals, families, businesses, schools, and media outlets to review their winter storm preparedness plans. It is especially important for all new arrivals to the state to become familiar with the National Weather Service watch and warning definitions, as well as winter safety procedures.

Snow in Colorado is important to the farmers, the ski areas, and for filling up reservoirs. However, winter storms often bring heavy snow, bitter cold air, high winds, low visibilities and slick roads. This can lead to dangerous travel conditions and other life threatening situations such as avalanches and very frigid wind chill temperatures.

To help you prepare for these hazards this coming winter…the National Weather Service will issue statements throughout the week to discuss:

Intro Winter Weather Preparedness Week
Part 1 Winter travel safety
Part 2 Watches…warnings…and advisories
Part 3 High winds
Part 4 Wind chill temperatures and hypothermia
Part 5 Avalanche safety
Review Winter Weather Preparedness Week review
Join the Discussion - Post your commentJoin the Discussion!

Denver sets record low temperature for the second day in a row

Friday, October 11th, 2019 5:23am MDT

Record Cold Temperatures

Last night temperatures dropped into record-setting territory. This morning that trend continued and set a record low temperature for October 11 as well.

As measured at Denver International Airport, the Mile High City’s official low temperature this morning was 9 degrees. That absolutely shattered the previous record low temperature for the date of 22 degrees set in 1946.

Thornton saw extremely cold temperatures as well, although not quite as cold as DIA. Our low came in at 15 degrees.

On a related note, yesterday’s snowfall was the first of the season and brought Thornton 3.3 inches of the white stuff.  Officially, as measured at DIA, Denver recorded 1.0 inches.

Friday and the weekend will see us break out of the cold with a warming trend that will see mercury levels back near normal on Sunday. Get the forecast here.

Join the Discussion - Post your commentJoin the Discussion!

Thornton’s Friday and weekend to go from record cold to seasonal warmth

Friday, October 11th, 2019 4:57am MDT

The three day period starts with record-shattering cold temperatures but will see things gradually warm up over the period and conditions will be dry and calm.

Friday morning brings mercury readings in the teens, well below the record low for the date of 22 degrees. We will see improvement on those numbers but cold air from yesterday’s storm will linger. Highs today will be in the mid to upper 40s under sunny skies. Tonight, skies remain clear with lows dropping back to the low to mid-20s.

Saturday will continue the calm, dry conditions and offer lots of sun above. Temperatures will warm to around the 60 degree mark. Saturday night into Sunday lows dip into the upper 20s.

Sunday will be the warmest day of the weekend with temperatures near normal. Highs will be near 70 degrees under sunny skies.

Have a great weekend!

Join the Discussion - Post your commentJoin the Discussion!

Denver sets record low temperature for October 10

Friday, October 11th, 2019 12:01am MDT

Record Cold TemperaturesWhile our first snowfall of the season had ended, the cold was just beginning.

Just before midnight on Thursday, the temperature at Denver International Airport fell to 13 degrees.

This easily beat the record low temperature for October 10 of 17 degrees set in 2009.

Thornton managed to stay warmer with our low of 20 degrees coming in the morning.

The temperature will continue to drop tonight and into early Friday morning. It starts with record setting cold and now we will wait and see just how cold it gets.

Looking ahead, the weekend will offer up gradually warming temperatures with Sunday returning us to near normal readings.

Join the Discussion - Post your commentJoin the Discussion!