Thornton, Colorado, USA
UpdatedSun, 24-Mar-2019 9:45pm MDT 


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Tuesday sees temps cool to close to normal, brings a slight chance for a shower

Tuesday, October 23rd, 2018 5:02am MDT

A little bit of a change in our weather today as a couple of troughs impact Colorado. Increased clouds and cooler temperatures are the most notable features but we do also have a bit of a chance to see some rain.

Partly cloudy skies start things off and we will have similar conditions above throughout the day. Winds will be calm this morning then a bit breezy in the afternoon. Temperatures will top out in the low to mid-60s.

Mid-afternoon through tonight brings us slight chances of a shower or two. There isn’t much to work with here so if it does rain, we aren’t expecting much.

Tonight, mostly cloudy skies remain above with a slight chance for lingering showers. Lows will be in the low 40s.

Keep an eye out for showers here.

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Thornton’s workweek starts out with mild temperatures, a few more clouds

Monday, October 22nd, 2018 5:01am MDT

We enjoyed some nice weather this past weekend and today we continue the warm conditions. There will however be more cloud cover due to moisture aloft.

The day starts out with mostly sunny skies. After noon, the moisture increases leading to additional cloud coverage. Temperatures will be topping out in the mid to upper 60s. Tonight, skies will be mostly cloudy with lows to around the 40 degree mark.

Looking ahead, a weak system moves through tomorrow cooling things down and bringing a bit of a chance for light rain into Wednesday. We will then rebound though with dry, calm conditions for the balance of the week. Get a look at our extended weather forecast here.

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

Sunday, October 21st, 2018 1:21am MDT
This week in Denver weather history

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

This week in Denver weather history is notable for one dominant weather condition: snow. In our look back through history we see many significant snow events, some of which occurred as recently as just last year.

From the National Weather Service:


In 2003…an extended warm spell resulted in 5 new temperature records. The high temperature of 84 degrees on the 18th equaled the record high for the date. High temperatures of 86 degrees on the 19th…83 degrees on the 21st…and 84 degrees on the 22nd were record highs for the dates. Low temperature of 49 degrees on the 23rd was a record high minimum for the date. Low temperatures during the period were in the 40’s and lower 50’s.


In 1906…heavy snowfall totaled 22.7 inches in the city over the 5 days. Rain changed to snow on the evening of the 19th…and snow continued through the late afternoon of the 23rd. The heaviest amount of snowfall…16.0 inches…fell from 8:00 pm on the 20th to 8:00 pm on the 22nd. The most snow on the ground was 13.3 inches on the evening of the 23rd. This was the first snow of the season and the only snow of the month. Winds during the storm were from the north at sustained speeds of 20 to 30 mph each day. Temperatures during the storm were generally in the 20’s.


In 2007…a storm system brought heavy snow to the southern Denver suburbs as well as the Palmer Divide south of Denver. Storm totals included: 7.5 inches near Castle Rock…Lone Tree and Greenwood Village…with 6.5 inches at Elizabeth. Snow drifts up to 2 feet deep were observed 6 miles south-southwest of Elizabeth. In the Denver Stapleton area…2.0 inches of snow was observed.

In 2009…heavy snow developed along the Palmer Divide south and southeast of Denver as a storm system tracked across southern Colorado and northern New Mexico. Storm totals included: 15 inches…15 miles north of Elizabeth…9 inches…5 miles south-southwest of Arapahoe Park; 8 inches in Highlands Ranch…5 miles south- southeast of Sedalia; 6.5 inches…8 miles southwest of Bennett and 6 inches in Parker. At Denver international… Only 1.5 inches of snowfall was observed.


In 1936…5.5 inches of snow fell over downtown Denver. Most of the snow…4.5 inches…fell on the 20th.


In 1920…the rare event of snow from a thunderstorm occurred in the city during the evening. Brilliant flashes of lightning and loud peals of thunder were first noted at 7:35 pm. Light rain began falling at 8:30 pm…and light moist snow began falling a few minutes later. Some soft hail was also seen falling with the rain and snow…but both melted almost as fast as they fell. The hail only continued for a few minutes…and the rain and snow ceased about 9:40 pm. The snowfall was the first to occur in Denver this season. The amount of precipitation at the station measured only 0.01 inch…but heavier amounts were reported from other parts of the city. Snowfall was only a trace.


In 1978…heavy rain on the 21st changed to snow by daybreak on the 22nd and continued the rest of the day. This was the first measurable snowfall of the season…but totaled only 1.7 inches at Stapleton International Airport where east winds gusted to 29 mph. While only a trace of snow covered the ground…precipitation totaled 1.27 inches.


In 1878…winds were sustained to 42 mph.

In 1887…the first measurable snow of the season occurred… Ending the longest snow-free period in Denver…232 days… Since the last snow on March 5th.

In 1947…the first snow of the season totaled only 1.6 inches. Post-frontal north winds caused temperatures to plunge from a high of 60 degrees at midnight to a low of only 30 degrees 24 hours later. This was the only snow of the month.

In 1985…high winds gusting from 60 to 80 mph buffeted the Front Range foothills. The strongest reported wind gust was 89 mph in eastern Boulder. A tree house east of Boulder was set on fire by a downed power line. Two people in Boulder were injured. A woman broke her arm when the strong winds knocked her to the ground. A carpenter in the city suffered a severely cut hand while he was trying to repair a roof that was being torn from a building. At Stapleton International Airport…northwest winds gusted to 41 mph.

In 2001…west-northwest winds gusting as high as 54 mph warmed the temperature to a high of 70 degrees at Denver International Airport.


In 1914…post-frontal rain changed to snow. Precipitation totaled 2.72 inches…most of which was in the form of moist snow which melted as it fell in the business section of the city. About 3 inches of snow was measured on lawns in the residential areas on the morning of the 24th. Official snowfall totaled only 0.4 inch downtown… But an estimated 8.0 inches of snow melted as it fell. North to northeast winds were sustained to 29 mph with gusts to 30 mph on both days.

In 1975…a vigorous cold front moving across metro Denver followed by strong northeast winds gusting to 52 mph produced billows of blowing dust and plunged the temperature 21 degrees in an hour. The surface visibility was reduced to 1/4 mile in blowing dust at Stapleton International Airport. The temperature cooled from a daily record high of 81 degrees to a low of 38 degrees by day’s end. The first snowfall of the season totaled 2.7 inches on the 23rd. This was the only measurable snow of the month at Stapleton International Airport.

In 1995…heavy snow fell on the palmer ridge south of Denver and in the foothills west of Denver where snow amounts ranged from 4 to 8 inches. Sedalia…south of Denver… Received 8 inches of snow. Winds strengthened on the plains and produced blizzard conditions…reducing surface visibilities to less than 1/4 mile. I-70 was closed from just east of Denver at Gun Club Road to the Kansas border. Ten inches of snow fell at Strasburg east of Denver where north winds at sustained speeds of 35 to 45 mph with gusts as high as 60 mph produced 2 to 4 foot drifts. Snowfall totaled only 2.2 inches at the site of the former Stapleton International Airport. North winds gusted to 51 mph at Denver International Airport.

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

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Winter Weather Preparedness Week recap

Saturday, October 20th, 2018 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 20 2018

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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A weekend of pleasant fall weather conditions ahead for Thornton

Friday, October 19th, 2018 4:51am MDT

This is the kind of fall weather we are used to and love here in Colorado. For the three day period look for lots of sun, calm conditions and pleasant temperatures.

Friday will see clear skies throughout the day with overall calm conditions. Winds might be just a touch breezy in the afternoon but nothing intrusive. Highs will be in the mid to upper 60s. Tonight, skies remain clear with lows dipping to the mid-30s.

Saturday brings a repeat of today’s weather with clear skies and highs again in the mid to upper 60s. Overnight Saturday night it will be cloudless with lows going down to the upper 30s.

Sunday will offer up the warmest temperatures of the day with a high near the 70 degree mark. There might be a few clouds but nothing that amounts to much.

Have a great weekend and be sure to get out and enjoy it! Live conditions.

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Avalanche safety – Be prepared or die

Friday, October 19th, 2018 4:45am 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 19 2018

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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Thornton’s Thursday to offer temps close to normal, some clouds

Thursday, October 18th, 2018 5:07am MDT

A relatively quiet day today much like what we saw yesterday. Temperatures do warm up a bit and get closer to normal than we have been in quite a while.

Some clouds will be present as the sun rises then mostly sunny skies take over until the afternoon when we again will see some coverage. Winds will generally be light and out of the southeast this morning then switch to come from the north in the afternoon.

Temperatures will top out today in the low 60s, within a couple degrees of the average high for the date of 64 degrees.

Tonight, partly cloudy skies will be above with lows around 40 degrees.

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Life threatening winter weather – Wind chill, frostbite and hypothermia

Thursday, October 18th, 2018 4:59am 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 18 2018

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. To learn more about wind chill, visit the national weather service internet site using lower case letters:  http://weather.gov/om/windchill.

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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High winds a major threat in Colorado during the winter

Wednesday, October 17th, 2018 5:03am MDT
Winter winds can not only make it miserable to be outside, they can also be dangerous.

Winter winds can not only make it miserable to be outside, they can also be dangerous.

As we often experience, high winds in Colorado can cause conditions to deteriorate rapidly.  They present a very real danger to life and property, especially when coupled with other winter conditions like snow.

Why does it seem like we get so much wind in the winter?  What causes this?  How can you prepare and protect yourself and your property?

In this third in a series on winter weather preparedness from the National Weather Service, ThorntonWeather.com helps you understand why we receive so much wind and how to prepare for it.

600 AM MDT WED OCT 17 2018


This week through October 20th is Winter Weather Preparedness Week in Colorado.

The two main causes of high winds in Colorado during the cold season are the air pressure difference between strong low pressure and cold high pressure systems, and Chinook winds developing across the Front Range and other eastern mountain ranges.

» Click here to read the rest of High winds a major threat in Colorado during the winter

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Wednesday temps remain a bit cool, will see more clouds and some breezy winds

Wednesday, October 17th, 2018 5:02am MDT

No significant changes in Thornton’s weather today. Temperatures will be similar to yesterday and cooler than normal but there will be some more clouds.

The day starts out with mostly clear skies then we will see a gradual increase in mid-level moisture leading to partly cloudy skies by mid-afternoon. Overall conditions will be calm although the afternoon will bring some breezy winds. Highs today will again top out in the mid-50s, about 10 degrees below normal.

Tonight, skies will be partly clear with lows close to the freezing mark.

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