Thornton, Colorado, USA
UpdatedThu, 19-Jul-2018 7:40am MDT 


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Cold front to bring changes in the weather to Thornton on Thursday

Thursday, February 15th, 2018 5:11am MDT

A bit of half and half today. The day starts out nice enough and will actually see high temps around normal. However, an approaching cold front will send the mercury down in the afternoon and offer up a slight chance for snow.

Mostly sunny skies will be above initially then a slow increase in cloud cover will occur as the front approaches. By this evening it will be mostly cloudy. Winds will be light initially then become a bit breezy by late morning and last into the evening with the front pushing through.

Temperatures will warm up nicely with us hitting our daytime high in the mid to upper 40s around noon or so. By about 3:00pm, the cold front will make itself felt in earnest and temperatures will decrease somewhat quickly.

After 3:00pm and the until about 10:00pm we do see slight chances for a bit of snow. Most of the moisture will be south of us though so a half inch is the best we could hope for and likely will be less.

Skies will clear overnight and low temperatures overnight will hit the mid-teens.

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Unseasonably warm temperatures Wednesday to be driven by downslope winds

Wednesday, February 14th, 2018 5:08am MDT

Some good, some not so good in today’s weather forecast for Thornton. While we will enjoy temperatures well above normal, we will also see a good bit of wind from the west.

Mostly sunny skies start things off and we will see a bit of an increase in coverage by about noon but still expect some blue up there. Temperatures start out chilly but then will see a steady increase with highs to the low to mid-60s.

Downslope winds are going to be the reason for those warm temperatures. Speeds will increase this morning, peaking in the afternoon. At their height, gusts could push toward 40mph.

Tonight, winds will ease gradually with overnight lows near the freezing mark.

Keep an eye on the temps and wind here.

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Thornton’s Tuesday to offer warmer temperatures, more sun

Tuesday, February 13th, 2018 5:14am MDT

Yesterday’s chill is set to move out and in its wake we will enjoy a pretty nice day today. Expect temperatures to be not too far off of normal for the date and a decent bit of sun.

The day starts with mostly sunny skies and we should have the same sky conditions for much of the day, perhaps a bit fewer clouds in the evening. Temperatures will start out on the chilly side but then warm up nicely with highs topping out in the mid to upper 40s.

Tonight, skies remain mostly clear with lows in the upper 20s.

All in all it should be a pretty nice winter day.

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Cold front keeps things chilly for Monday, might offer some flurries

Monday, February 12th, 2018 5:03am MDT

A cold front has arrived this morning and that is going to chill us out again. While temperatures will be cold, we aren’t expecting much in the way of precipitation though.

The day starts with mostly cloudy skies and we can expect similar sky conditions throughout the day. The mercury is going to remain below freezing with highs today only in the mid to upper 20s. Some light snow / flurries will be possible this morning into the first part of tonight. However, there isn’t much moisture to work with so little, if any, accumulation is expected.

Tonight, skies will begin to clear and any snow should be done by about 10:00pm. Lows tonight will dip into the teens.

Previewing the balance of the week, it looks to be a bit of a roller coaster. After today’s chill, Tuesday and Wednesday will warm up nicely followed by our next chance for snow Thursday. We then should see drying, warming conditions for Friday and the weekend. Get more details in the extended weather forecast here.

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Cold front to bring unsettled weather for start of Thornton’s weekend

Friday, February 9th, 2018 5:03am MDT

Quite a bit of a change in our weather. A cold front moved through last night and that will offer up much colder temps and bring chances for precipitation today and Saturday.

For today, areas of dense fog start things of and a few spots of freezing drizzle may be seen in the morning. The bulk of the daytime should remain dry then this evening some drizzle and a few flakes of snow may be seen. Temperatures today will be chilly with highs in the mid-30s under mostly cloudy skies.

Overnight tonight we may see some freezing drizzle, a bit of snow but with little accumulation. Temperatures are going to get quite cold with lows down well into the teens.

Saturday is when we expect moisture to increase and give us our best chance for snow. The best opportunity comes tomorrow afternoon with things ending in the late evening. Overall, we could see a couple of inches of the white stuff. Highs tomorrow will only be in the low to mid-20s with cloudy skies.

As the system moves out Saturday night, skies will begin to clear and that will lead to very cold temps. Lows into Sunday morning are expected to hit the single digits.

The good news is that Sunday sees things start to turn around. There will be plenty of sun and temperatures should rebound nicely to around the 40 degree mark.

Stay safe, stay warm!

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Temperatures to climb Thursday but so will the wind speeds

Thursday, February 8th, 2018 5:10am MDT

A bit of good and bad with our weather today. We will enjoy our mildest day of the week with temps pushing close to 20 degrees above normal. However, much of that warmth will be the result of some pretty strong, downslope winds that we will be experiencing.

The day starts out mostly sunny and similar sky conditions should be above throughout the day. We start out a bit chilly but not as cold as usual thus giving us a head start toward our high temperature today in the low to mid-60s.

Winds will be a bit breezy initially this morning then increase in speed as the day progresses, peaking around 3:00pm with gusts to 35mph or so before gradually easing in the evening and the first part of tonight.

Tonight, partly clear skies will be above with lows dipping to the mid to upper 20s.

The wind won’t make it easy but enjoy that warmth today if you can as things will be turning colder, particularly tomorrow and Saturday. Have a look at the extended weather forecast here.

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Mild temperatures and a good bit of sun on Wednesday

Wednesday, February 7th, 2018 5:10am MDT

Thornton is set to enjoy a pretty nice day today. The mercury will rise a good bit higher than normal and other than a touch of wind, it will be a pleasant one.

The day starts off with some fog in a few places but that won’t last long. Once gone, we will be left with mostly sunny skies until the late afternoon when a few more clouds will build.

Some breezy winds will arrive this afternoon but nothing overly strong. Aided by the downslope winds, temperatures will top out in the mid-50s.

Overnight tonight, look for partly cloudy skies above with lows dipping to around 30 degrees.

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Thornton’s Tuesday to offer up typical weather for this time of year

Tuesday, February 6th, 2018 5:54am MDT

The little bit of snow we were expecting (hoping for) last night never did materialize as downslope flow kept it to our east. Today we remain dry with conditions pretty much on par with what we expect during the first part of February.

The day starts with a good bit of cloud cover but then we should see some clearing as the morning progresses. Overall look for partly to mostly sunny skies for much of the day. Temperatures start out chilly then we should see a high in the mid-40s. Average high for today’s date is 45 degrees and we should be right there.

Tonight, skies will be seeing some clearing and overnight lows dipping into the low 20s.

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February 4 to February 10: This week in Denver weather history

Monday, February 5th, 2018 5:45pm MDT
This week in Denver weather history

February 4 to February 10: This week in Denver weather history

February is generally a relatively calm weather month however just like any other month in Denver, it can and does see its extremes. In looking back at the Denver weather history calendar for the week, there are many entries for damaging wind, some heavy snowfall and extreme cold.

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 2011…a frigid arctic airmass settled into Front Range urban corridor. At Denver International Airport… Overnight low temperatures…from the 1st to the 3rd… Were 13 below zero…17 below zero and zero respectively. The icy temperatures caused pipes to crack and burst following the freeze. In Loveland…firefighters responded to more than a dozen water pipe breaks…most in fire sprinkler systems at businesses…apartments and assisted care facilities. At cu earth science library in Boulder…more than 1000 books and several costumes for an upcoming production were damaged. At the county courts administration building in Jefferson County…a steady stream of water from a crack on the 5th floor… Went unnoticed on the 3rd and flooded all the floors of the administration wing overnight. As a result…much of the office equipment…furniture and carpet sustained water damage. A burst sprinkler line caused minor damage at the Platte Valley Medical Center in Brighton. The icy temperatures forced to closure of several school districts as well.


In 1985…the most bitter cold spell of the winter season brought sub-zero temperatures to metro Denver. Daily low temperature records were broken at Denver. The usual cold weather problems struck including stalled vehicles…jammed traffic lights…and frozen water and sewer lines. At Stapleton International Airport…the high temperature was only 2 degrees above zero on the 1st…setting a record low maximum for the date. Low temperatures reached 13 below zero on the 1st…12 below on the third…and 14 below on the 5th.


In 1989…one of the century’s worst doses of winter weather ravaged the entire state. Bitterly frigid weather moved into metro Denver on the 1st as snow buried many sections of the state. In metro Denver where 3 to 6 inches of snow fell…blowing snow and resultant poor visibilities caused a 46-car pile-up on I-25 in the middle of the city on the 4th. During the period…2 to 3 hour delays were common at Stapleton International Airport where snowfall from the storm totaled 4.3 inches and northeast winds gusted to 30 mph on the 1st. Intense cold accompanied the storm. Temperatures in Denver stayed below zero continuously for the best part of 3 days (3rd…4th…5th)…for a total of 69 hours. This is the fourth longest sub-zero period on record. Wind chill temperatures reached 50 degrees below zero. The mercury dipped to 24 degrees below zero on the 5th…setting a record for the date. This was the city’s coldest temperature in over 26 years. Low temperatures dipped below zero on 8 consecutive days (2nd-9th). High temperature of 9 degrees below zero on the 4th was a record low maximum for the date…as was the high of 5 degrees on the 5th. Extensive damage occurred when pipes and water lines froze and broke. Thousands of cars failed to start. On the 3rd…a 57-year-old woman died of hypothermia in an Arvada park. Eighteen high school students were treated for hypothermia after a 2-hour ride through Jefferson County in an unheated bus. At least 2 cases of frostbite were reported; there were undoubtedly many more.


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 2012…a slow moving and powerful storm system brought heavy snow to areas in and near the Front Range Foothills and Palmer Divide…with blizzard conditions over the northeast plains of Colorado. In the Front Range Foothills…the snow piled up to over 4 feet in some areas. Across the Palmer Divide…the combination of snow and gusty winds resulted in road closures with snow drifts ranging from 2 to 5 feet in depth. Northerly winds 15 to 25 mph were common with gusts to 40 mph. Several snowfall records were also set in Denver. At Denver International Airport…12.5 inches of snow feet on the 3rd shattered the previous record of 7.5 inches for the date. It also set a new daily record for the entire month of February. A new 3-day record was also established for Denver. The 3-day storm total from February 2nd to the 4th was 15.9 inches… which broke the previous record of 14.1 inches in 1912. Denver International Airport canceled more than six hundred flights. In addition…snow and blowing snow produced near zero visibilities…forcing officials to close the westbound lanes of Interstate 70…between the Kansas state line and Denver… as well as the eastbound lanes from Denver to Limon. Other road closures included State Highway 86…between Kiowa and I-70. Across the Urban Corridor storm totals included: 22 inches in Broomfield; 21 inches at Lafayette…Louisville and Westminster; 20 inches at Northglenn; 19 inches at the National Weather Service in Boulder…Castle Rock… Centenniel and Parker; 18 inches in Arvada…16.5 inches in Erie… 13.5 inches near Longmont; 11 inches in Lyons and 10 inches in Frederick. Storm totals in the mountains and foothills included: 51 inches at Coal Creek Canyon…45.5 inches… 4.6 miles northeast of Ward; 44.5 inches…3 miles west of Jamestown; 38 inches… 3 miles north of Blackhawk; 37 inches…3 miles west-southwest of Conifer and 4 miles east-northeast of Nederland; 35.5 inches… 3.6 miles west-northwest of Boulder; 34 inches…5.2 miles east-southeast of Aspen Springs; 33 inches near Evergreen…32 inches at Genesee; 31 inches…10.3 miles west of Bellvue and Eldora Mountain Ski Resort; 24 inches at Echo Mountain Ski Resort; 21 inches at Niwot Ridge SNOTEL; and 19 inches at Gross Reservoir. Along the Palmer Divide storm totals included: 26 inches…14 miles east-northeast of Kiowa; 25 inches…10 miles south-southwest of Buckley Air Force Base…and 8 miles southeast of Watkins; 20 inches near Strasburg; 12 inches near Elizabeth.


In 1906…northeast winds were sustained to 43 mph behind a cold front on the 3rd. The front plunged temperatures from a high of 62 degrees on the 3rd to a low of 24 degrees…which was also the high reading on the 4th. The low temperature on the 4th was only 3 degrees. Snowfall was only 0.6 inch on the 4th.

In 1970…a wind gust to 115 mph was recorded in Boulder at the National Center for Atmospheric Research. Sustained winds of 35 mph with gusts as high as 62 mph were measured in downtown Boulder. Northwest winds gusted to 47 mph at Stapleton International Airport on the 3rd.


In 1982…a cold surge of arctic air brought light snow and sub-zero temperatures to metro Denver. Temperatures plunged to 6 below zero at midnight on the 3rd and never warmed above zero on the 4th as snow flurries continued. High temperature on the 4th of 1 below zero was a record low maximum. The temperature dipped to a record low of 15 below zero on the 5th.


In 1883…the temperature plunged to a low of 22 degrees below zero.

In 1885…a windstorm occurred in the city during the afternoon and early evening. West winds sustained to 64 mph blew down several trees…chimneys…awnings… And sheds. Stronger winds in the foothills blew a train from the track at Georgetown…injuring several passengers.

In 1890…the highest recorded temperature in February… 77 degrees…occurred. This temperature was equaled on February 28…2006.

In 1898…west winds were sustained to 53 mph with gusts to 60 mph.

In 1915…very strong northwest winds whipped downtown Denver nearly all day. There were 13 consecutive hours with maximum sustained velocities ranging from 27 to 44 mph. An extreme velocity to 46 mph was recorded.

In 1952…a northwest wind gust to 48 mph was recorded at Stapleton Airport. Severe winds were reported west and north of Denver.

In 1995…high winds developed in the foothills west and northwest of Denver. A gust to 97 mph was recorded on Squaw Mountain. Winds were clocked to 83 mph at Rollinsville. Wind gusts between 50 and 70 mph were common. North winds gusted to only 31 mph at Stapleton International Airport.

» Click here to read the rest of February 4 to February 10: This week in Denver weather history

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January 2018 weather recap: Above normal temps with snow and precip near average

Monday, February 5th, 2018 5:44pm MDT

The month of January saw little in the way of weather drama.  Temperatures definitely trended toward the warm side though and while the month’s snowfall came it close to normal, we head into March with a seasonal deficit.

New Year’s Day started the month off cold but then we began a warming trend that saw average temperatures dominantly above normal for the first two weeks of the month. Precipitation was almost entirely absent during the period other than a bit of rain on the 10th.

On the 15th conditions like we expect in January returned – but only for two days. A quick, light shot of snow arrived and temperatures cooled to below normal.

We then returned to largely warmer than normal conditions until the 21st when we got not only our biggest snow of the month, but our biggest of the season so far.  Sadly, that was only 4.9 inches of the white stuff.

From there, eight of the last ten days of the month saw above normal temperatures and no precipitation.

Thornton’s average temperature for January 2018 came in at 32.9 degrees.  Denver’s long term average for the month is 30.7 degrees.  Out at the airport where the Mile High City’s official measurements are taken, it was considerably warmer with an average of 34.7 degrees.

Our high temperatures ranged from a high of 69.3 degrees on the 9th down to a low of 0 degrees on the morning of the 16th.  DIA recorded highs of 68 degrees and a low of -4 degrees on those same dates.

On average, Denver receives 0.41 inches of liquid precipitation in January.  Thornton was just a hair above that with 0.44 inches and Denver bested that with 0.54 inches.

We recorded 6.1 inches of snow in Thornton during the month while the airport was just a bit higher with 6.4 inches.  Both were short of Denver’s January average of 7.0 inches.

Click here to view Thornton’s January 2018 climate report.

Thornton, Colorado's January 2018 temperature summary. (ThorntonWeather.com)

Thornton, Colorado’s January 2018 temperature summary. (ThorntonWeather.com)

Thornton, Colorado's January 2018 precipitation summary. (ThorntonWeather.com)

Thornton, Colorado’s January 2018 precipitation summary. (ThorntonWeather.com)

650 AM MST THU FEB 1 2018




                 VALUE   DATE(S)  VALUE   FROM    VALUE  DATE(S)
 HIGH              76   01/27/1888
 LOW              -29   01/09/1875
HIGHEST            68   01/09        76      -8       63  01/30
LOWEST             -4   01/16       -29      25       -7  01/06
AVG. MAXIMUM     49.2              44.0     5.2     42.3
AVG. MINIMUM     20.1              17.4     2.7     17.7
MEAN             34.7              30.7     4.0     30.0
DAYS MAX >= 90      0               0.0     0.0        0
DAYS MAX <= 32      3               5.5    -2.5        8
DAYS MIN <= 32     28              29.4    -1.4       30
DAYS MIN <= 0       2               1.7     0.3        2

 MAXIMUM         2.35   1883
 MINIMUM         0.01   1933
TOTALS           0.54              0.41    0.13     0.54
DAILY AVG.       0.02              0.01    0.01     0.02
DAYS >= .01         5               4.1     0.9        3
DAYS >= .10         2               0.9     1.1        3
DAYS >= .50         0               0.0     0.0        0
DAYS >= 1.00        0               0.0     0.0        0
 24 HR. TOTAL    0.30   01/21 TO 01/21

TOTALS            6.4               7.0
 MAX TOTAL       24.3   1992

HEATING TOTAL     932              1063    -131     1075
 SINCE 7/1       3082              3531    -449     3117
COOLING TOTAL       0                 0       0        0
 SINCE 1/1          0                 0       0        0

 EARLIEST     09/08/1962
 LATEST       06/08/2007
EARLIEST                        10/07
LATEST                          05/05

AVERAGE WIND SPEED              9.3

AVERAGE SKY COVER           0.50
NUMBER OF DAYS FAIR            6
NUMBER OF DAYS PC             21


HEAVY RAIN             2    MIXED PRECIP            3
LIGHT RAIN           0    RAIN                    1
LT FREEZING RAIN       0    FREEZING RAIN           0
HEAVY SNOW             3    HAIL                    0
LIGHT SNOW             0    SNOW                    7
FOG                    1    FOG W/VIS <=1/4 MILE    1
HAZE                   4

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