Thornton, Colorado, USA
UpdatedSun, 07-Mar-2021 2:30pm MST 


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The big chill arrives for Thornton’s weekend

Friday, February 12th, 2021 5:39am MST

Well, we have been talking about this for a week now and it is here. Arctic air has moved in and will continue to be reinforced leading to a bitterly cold weekend.

For Friday, cloudy skies will be above and light snow / flurries will be seen much of the day. Little accumulation will be seen though. High temperatures today will top out in the upper teens. Tonight, skies will remain mostly cloudy with a few flurries. Overnight lows will push toward the zero degree mark.

Saturday looks similar to today although we might see a few periods of time when the sun peeks out. Highs will remain cold and in the mid to upper teens. Flurries will be possible throughout. Saturday night, we see the chances for snow increase and may see some light accumulations. Overnight lows Saturday night into Sunday morning dip into negative territory.

Any accumulating snow will end Sunday morning leaving only flurries. If we are lucky, we could see a couple of inches total. Sunday will be cloudy and the coldest day of the period with highs expected to only be in the single digits. Sunday night, with skies beginning to clear, lows are expected to dip well below zero.

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Thornton’s Thursday repeats cold conditions of recent days

Thursday, February 11th, 2021 4:53am MST

A virtual clone of the weather forecast for the last couple of days. Today will offer cloudy skies and a few flakes of snow early to be followed by some clearing but with chilly temps.

Cloudy skies and some fog start us off. As with the last couple of days, a few flurries will be possible before 10:00am but with no accumulation expected. We will then see some blue sky return by mid-morning and last through the rest of the day.

Highs today will push close to the freezing mark. Breezy winds this afternoon will make it seem colder than what the thermometer reads. While cold, enjoy it because it will be next week before we see temperatures that “warm” again.

Tonight, the first push of Arctic air will be moving in leading to single digit temperatures overnight. Some light snow with minimal, if any, accumulation will be possible after midnight.

How cold will the coming days be? See the extended forecast here.

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February 7 to February 13: This week in Denver weather history

Wednesday, February 10th, 2021 5:13am MST

This Week in Denver Weather History

You can tell how eventful a week in Denver weather history is by the length of these articles and this one is a long one for sure.  In history we have seen Arctic cold, spring-like warmth, major snowstorms and blizzards and hurricane force winds.  There is even a rare thunderstorm that dropped a bit of hail.

From the National Weather Service:


In 1985…a cold front on the 29th produced a protracted cold spell as arctic air remained entrenched across metro Denver. While the only daily temperature record set was a low maximum reading of 2 degrees on February 3rd…minimum temperatures plunged well below zero on 9 consecutive days. The coldest readings were 15 degrees below zero on January 31st and 14 degrees below zero on February 5th.


In 1963…warm weather that began with the strong Chinook winds on the 31st and 1st continued through the 8th. Maximum temperatures through the period ranged from 52 degrees on the 2nd to 76 degrees on the 5th…which was a new record high for that date.


In 1899…a protracted cold spell lasted almost two weeks. Low temperatures plunged below zero on all days but February 9th with a reading of 6 degrees.  The coldest low temperature of 22 degrees below zero on February 6th was a record low for the date.  Low temperatures of 20 degrees below zero occurred on both February 11th and 12th… But only the 11th remains as the record minimum for the date.  High temperature of only 5 degrees below zero on February 11th was a record low maximum for the date.  High temperatures climbed to only zero degrees on both February 2nd and 3rd…but were not records.  Intermittent light snow or flurries fell during the period.  The most snowfall…2.0 inches…occurred on February 2nd.


In 1883…a protracted cold period occurred when low temperatures dipped below zero for 9 consecutive days. Low temperatures ranged from 22 degrees below zero on the 4th to 2 degrees below zero on the 1st and 6th.  High temperatures ranged from 10 below zero on the 3rd to 23 on the 9th.  Several temperature records were set that still stand today.  Record lows of 18 below and 22 below zero occurred on the 3rd and 4th.  Record low maximum readings of 2 below and 10 below zero occurred on the 2nd and 3rd.  The high of only 10 below zero on the 3rd is the coldest maximum temperature ever recorded in Denver.


In 1978…the 5th marked the start of a record 7 consecutive days of dense fog at Stapleton International Airport.  The heavy fog reduced the visibility to 1/4 mile or less for a period of time on each of these days.  Light snow and/or freezing drizzle occurred on most days.  Fog reducing visibility to less than 7 miles was recorded at Stapleton International Airport on 11 consecutive days through the 15th.  During the period 5-14…the cold thick fog deposited heavy rime ice up to 5 inches thick on power lines and poles over a wide area of eastern Colorado…causing a major electrical power outage disaster.


In 1929…5.0 inches of snow fell in downtown Denver behind a Canadian cold front.  Temperatures plunged…but no records were set.  Low readings dipped to 3 degrees below zero on the 6th and 9 degrees below zero on the 7th.  Highs climbed to 5 degrees on the 6th and to only 1 degree below zero on the 7th.

In 1933…post-frontal light snowfall totaled 3.0 inches over downtown Denver.  Northeast winds were sustained to 28 mph with gusts to 32 mph on the 6th.  The very cold air mass plunged temperatures from a high of 60 degrees on the 5th to lows of 10 degrees below zero on the 6th and 16 degrees below on the 7th.  High temperature of only 4 degrees below zero on the 7th was a record low maximum for the date.


In 1933…3:00 pm on the 6th marked the start of a protracted cold period through 8:00 am on the 10th when the temperature was below zero for 86 out of 88 hours.  The cold period was interrupted on the 8th at 9:00 am when the temperature was 1 degree above zero and at 10:00 am when the temperature was 8 degrees above zero.  Four temperature records were set. High temperatures of 4 degrees below zero on the 7th…8 degrees on the 8th…and 5 degrees below zero on the 9th were record low maximums for those dates.  The only record low temperature record was 14 degrees below zero on the 10th. The lowest temperature reached during the period was 16 degrees below zero on both the 7th and 8th…which were not records.


In 1940…a distant thunderstorm was recorded.  This was only the second ever recorded in the city during February since 1900.

In 1976…strong Chinook winds were reported along the foothills with sustained winds at 46 mph and gusts to 69 mph at the National Center for Atmospheric Research in Boulder.  Wind gusts of 70 to 90 mph were recorded at other locations in Boulder.  Northwest winds gusted to 44 mph at Stapleton International Airport.

In 1979…strong west winds gusted as high as 99 mph near Boulder.  The winds caused ground blizzards that closed several highways around Boulder.  Some cars were forced off the road…and a truck was overturned.  Wind gusts of 50 to 80 mph were common in and near the foothills.  Northwest winds gusted to 33 mph at Stapleton International Airport.

In 1988…a wind gust to 82 mph was clocked at Rollinsville in the foothills southwest of Boulder.

In 1999…strong Chinook winds developed in the foothills. Peak wind reports included:  90 mph at the National Center for Atmospheric Research Mesa Lab near Boulder and 88 mph at Wondervu in the foothills southwest of Boulder. West to southwest winds gusted to only 48 mph at Denver International Airport.

» Click here to read the rest of February 7 to February 13: This week in Denver weather history

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Another cold one for Thornton Wednesday with conditions much like yesterday

Wednesday, February 10th, 2021 4:59am MST

Very little difference between today’s forecast and the weather we saw yesterday. Very cold temps and perhaps a flurry start things off but then some clearing with temps remaining well below normal.

Cloudy skies and some patchy fog start us off. By mid-morning cloud cover will begin to ease. Like yesterday, a few flurries of snow will be possible in the morning but with no accumulation. High temperatures today will top out in the upper 20s, well below the average high of 45 degrees for the date.

Tonight, partly clear skies will be above with some fog possible early tomorrow morning. Lows will be in the low 10s.

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Tuesday to offer up chilly temperatures, a good bit of cloud cover

Tuesday, February 9th, 2021 5:30am MST

We had hoped for a bit warmer day today but that doesn’t look to be in the cards. With no lower level dynamics available to move out the cold, temps will be well below normal.

Mostly cloudy skies start us off and then by mid-morning the cover will ease just a bit letting through some more sun. Overall conditions will be dry and calm. Temperatures start out quite cold, close to the single digits, and will climb but only top out in the upper 20s / lower 30s.

Tonight, skies will be mostly cloudy with overnight lows in the low teens.

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Thornton’s workweek starts off with temps near normal, colder weather on the horizon

Monday, February 8th, 2021 5:12am MST

Monday will offer up a relatively typical day with highs near average and a good bit of sun. All eyes are currently focused on an incursion of cold air expected to send the mercury plummeting later this week.

For today, early on we will have a good bit of cloud cover, some fog, and may even have a few flakes of snow fall. That will be ending soon after sunrise though and skies will begin to clear with mostly sunny skies being above for the latter part of the day. Winds will be a bit breezy today although nowhere near as strong and persistent as yesterday. Look for highs right near the average high for the date of 45 degrees.

Tonight, cloud cover will again be increasing and overnight lows will drop to around 20 degrees.

Looking ahead, today will be the warmest day of your workweek as will get gradually colder as the week progresses. Assuming the Arctic air moves as far south as expected, highs from Friday through Sunday may not even reach the freezing mark! Have a closer look at the extended weather forecast here.

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Thornton’s weekend to feature dry and relatively calm conditions

Friday, February 5th, 2021 4:58am MST

Not a heck of a lot exciting to talk about with this weekend’s weather as things look to be calm, temperatures at or above normal. More notable is the expected cold set to arrive next week.

For today, wave clouds are expected to setup and keep things partly sunny. High temperatures will top out right near the average high for the date of 45 degrees. Winds will be a bit breezy but shouldn’t be too bad. Tonight, skies will be partly cloudy with lows in the low to mid-20s.

Saturday brings more sun into the forecast with mostly sunny skies above throughout. Highs will again be in the mid-40s. Some, slightly breezy winds may be seen. Saturday night into Sunday morning, skies will be mostly clear and lows will drop to the mid-20s.

Sunday looks to be the warmest day of the period with highs in the low to mid-50s. Sunny skies will be above. We do expect to have some breezy winds in the afternoon.

Looking ahead, an incursion of Arctic air is expected to dive south late Monday and that will send the mercury down. Highs in the Tuesday to Thursday period may not climb above freezing. Until then, enjoy the relatively warmth of this weekend!

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A chilly, blustery Thursday for Thornton

Thursday, February 4th, 2021 5:05am MST

With only a few drops of rain, yesterday’s storm system had little impact on us. Today, as it moves out, we will see a good bit of sun but temps remain below normal and we will have some wind.

Mostly sunny skies will be the general rule throughout the day. Winds will start out relatively calm then be ramping up by mid-morning. At their height, around noon, gusts to 30mph will be possible. High temperatures today will top out around 40 degrees, about 5 degrees below average for the date.

Tonight, winds will be a bit breezy but slowly ease up. Overnight lows will drop to the low 20s under mostly cloudy skies.

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Thornton’s February 2021 weather preview: Temps begin to warm, snow can be elusive

Wednesday, February 3rd, 2021 7:36am MST

February in Colorado typically brings to an end an extended period when average temperatures are at their lowest. Winter begins to loosen its grip and temperatures get warmer but precipitation is not a particularly common event during the month.

Thus far, our snow season has been a bit of a disappointment. Things looked hopeful at the start but the last couple of months have seen things really lag .  February is only our sixth snowiest month so we may not see much improvement in the seasonal totals this month.

Temperatures however do usually see a nice rebound during the month. Average high temperatures climb from an average of 44 degrees at the start to 50 degrees by the end of February.

For the complete February preview including a look at historical averages and extremes as well as a look at what long range forecasts are predicting, click here. 

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Mild temperatures, breezy winds Wednesday with a cold front arriving late

Wednesday, February 3rd, 2021 5:23am MST

Hopefully you have enjoyed the relatively warmth of the last few days. Today, we begin to see things chill out although at this time it doesn’t appear it will be particularly extreme and moisture will be lacking.

The day starts out with mostly sunny skies then this afternoon brings an increase in cloud cover. Winds will be becoming breezy by about mid-morning and an approaching front starts to make itself felt. Look for those breezy winds to be with us for the next 36 hours or so. Temperatures will be mild today with highs again reaching the low 60s.

The front will arrive this evening and with it, we may see a bit of light rain before midnight. Then, as overnight temperatures drop, a little bit of snow will be possible. Only minimal, if any, accumulations are expected. Any precipitation should end in the pre-dawn hours tomorrow. Overnight lows will be dropping to the mid-20s under mostly cloudy skies.

Looking further ahead, temperatures at or below normal are going to be the rule well into next week. Unfortunately, moisture is not going to be much of a part of the equation. See the extended forecast here.

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