Thornton, Colorado, USA
UpdatedThu, 20-Sep-2018 4:40am MDT 


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Another warm and windy day for Thornton’s Thursday, snow possible tonight and tomorrow

Thursday, April 12th, 2018 5:15am MDT

A little bit of ‘fire and ice’ in the weather forecast over the next 48 hours or so. We start out with unseasonably warm temperatures and high fire danger today but then will see much colder temperatures and a chance for snow tomorrow.

For today, we start out with partly sunny skies then will see some clearing in the afternoon leading to mostly sunny skies. Winds today will be similar to yesterday with speeds increasing by mid to late morning. They will continue to be quite breezy through tonight. Temperatures today will top out in the upper 70s, coming close to Denver’s record high for the date of 79 degrees.

The wind coupled with low humidity and dry fuels means another Red Flag Warning will be in effect until 9:00pm so please be careful.

Tonight, we may see a sprinkle of rain, perhaps some snow after midnight but little or no accumulation is expected. Lows will dip to the mid-30s.

Friday is going to see a return of blustery, wintry conditions with highs only around 40 degrees, chilly winds and some light snow.

What lies ahead for the weekend? Check out the extended forecast here.

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High fire danger, potentially record-setting temps for Thornton’s Wednesday

Wednesday, April 11th, 2018 5:06am MDT

An unseasonably warm day on tap for us today with mercury readings that will push toward the record high for the date. However, those temperatures will be coupled with critical fire danger that has prompted a Red Flag Warning.

The day starts off with a good bit of cloud cover but skies will be clearing by mid-morning leading to mostly sunny skies for much of the day.

Temperatures start out warm, aided by downslope flow, and will head toward a high temperature near the 80 degree mark. Denver’s record high temperature for today’s date is 80 degrees, set in 1982, so it is in jeopardy.

The main story will be winds out of the west that will be increasing in speed this morning and continuing into the early evening. Those winds coupled with dry fuels and low humidity will lead to increased fire danger. A Red Flag Warning has been issued and will be in effect from 11:00am to 7:00pm. Please be careful out there!

Tonight, winds will be calm and skies partly clear as we head for a low in the mid-40s.

Tomorrow, we do this all over again but with even stronger winds and even higher fire danger. Keep an eye on current weather conditions here.

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Thornton to enjoy a very pleasant Tuesday with mild temps, lots of sun

Tuesday, April 10th, 2018 4:53am MDT

Aw, yes, today will be one of those days that you just have to love living in Colorado. It will be, overall, the most pleasant day of the week as we enjoy unseasonably warm temps and lots of sun.

The day starts with sunny skies which will continue through the morning. This afternoon will see clouds increasing but nothing too intrusive. Winds will be relatively light and out of the southwest initially then shifting to the west. As for temperatures, it starts out chilly but then the mercury will begin a steady climb toward an afternoon high in the low 70s.

Tonight, look for mostly cloudy skies with lows dipping to the mid-40s.

Looking ahead, Wednesday and Thursday are going to actually be warmer than today and in fact will probably bring our warmest temperatures of the year thus far. However, we also are going to have a good deal of wind. That wind, the low humidity and dry fuels have already prompted a Red Flag Warning to be issued for Wednesday and Thursday as fire danger increases.

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Some snow and rain possible early Monday, then clearing skies

Monday, April 9th, 2018 5:05am MDT

A disturbance is moving through this morning that has brought us a few sprinkles of rain and may yet deliver some flakes of snow. Any precipitation won’t amount to much though and the latter half of the day will be calm and dry.

Mostly cloudy skies start things off and will continue through the first part of the morning. Then, skies will begin to clear with mostly sunny skies above for the afternoon and evening.

Some snow may be seen in the pre-dawn hours then perhaps mixed with some rain after sunrise. Little to no accumulation is expected. Precipitation should end by noon.

Temperatures start out chilly then will be slow to climb with today’s high in the mid-50s.

Tonight, skies will be mostly clear with lows dipping to near freezing.

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April 8 to April 14: This week in Denver weather history

Sunday, April 8th, 2018 5:33am MDT
This week in Denver weather history

April 8 to April 14: This week in Denver weather history

April can be a very eventful weather month and we see that in our look back at this week in Denver weather history. Particularly notable are many major snow events including two in recent history – one in 2001 and another in 2005.

From the National Weather Service:


In 1973…a major spring snow storm dumped 11.6 inches of snowfall over metro Denver. North wind gusts of 30 to 35 mph produced some blowing snow. Most of the heavy wet snow… 10.1 inches…fell on the 7th when temperatures remained in the 20’s. Snow accumulated on the ground to a maximum depth of 9 inches. Low temperature of 5 degrees on the 8th was a new record minimum for the date and the lowest for so late in the season.


In 1913…heavy snowfall totaled 10.9 inches in downtown Denver behind a cold front. Most of the snow fell on the 8th. Northeast winds were sustained to 35 mph with gusts to 38 mph on the 9th.

In 1935…moderate dust blew into the city around 9:00 pm on the 7th and persisted until early afternoon on the 9th. Southeast winds were sustained to around 20 mph on the 7th and 8th. Winds shifting to the west at sustained speeds to 20 mph cleared the dust from the air on the 9th.


In 1959…snow falling over a 5-day period totaled 20 to 30 inches just east of the mountains…while over the plains blizzard conditions closed schools and blocked highways. The second big storm in two weeks dumped 16.4 inches of snowfall on Stapleton Airport with the most…11.6 inches… Occurring on the 8th. East winds gusted to 37 mph on the 9th. Temperatures dipped into the single digits on the mornings of the 7th and 12th when 7 degrees were registered. Low temperature records for the dates were set on the 9th…10th…and 12th. The cold temperatures caused streets to glaze with ice…resulting in the death of a pedestrian who was struck by a car in Denver. Three people died from heart attacks while shoveling the heavy… Wet snow.


In 1885…dense smoke polluted the air until noon.

In 1887…south winds were sustained to 42 mph.

In 1890…northwest winds were sustained to 48 mph with gusts as high as 60 mph.

In 2005…a mixture of strong pressure gradient winds coupled with thunderstorm outflow winds produced high winds across metro Denver. The high winds downed power lines and knocked out electricity to about 19 thousand customers on the east side of metro Denver. High wind reports included gusts to 68 mph in Longmont…61 mph near Castle Rock…59 mph at Centennial Airport…and 54 mph at Denver International Airport.


In 2013…heavy snow developed in and near the Front Range Foothills and Palmer Divide as an upper level trough made its way across southern Colorado. Snowfall was enhanced locally with the presence of an upper level jet. Storm totals included: 23 inches near Eldorado Springs…18 inches just west of Boulder…16.5 inches near Orodell…15 inches…4 miles west-northwest of Boulder; 13 inches at Gold Hill; 12 inches at the National Weather Service Office in Boulder…11 inches in Ken Caryl; 8.5 inches near Morrison; 8 inches at Genesee and Roxborough Park; 7.5 inches near Arapahoe Park; with 6.5 inches at Denver International Airport.


In 1999…a windstorm caused 20 million dollars in damage along the Front Range urban corridor from Fort Collins south to pueblo and to the east over the plains…making the storm equal to the costliest windstorm ever…which occurred in Boulder on January 17…1982. In metro Denver… Several homes were damaged as shingles were blown off roofs. Large pieces of a roof torn off a strip mall in Lakewood damaged several cars in a parking lot. Most of the damage to homes consisted of broken fences…awnings…doors…and windows. Scores of automobiles suffered broken or cracked windshields and paint damage from flying debris. Multiple accidents were triggered as several tractor-trailer rigs were blown on their sides by the strong cross-winds. Blowing dust and dirt caused near zero visibilities at times. Both I-25 and I-76 were closed north and northeast of Denver. State Highway 93 was closed between Golden and Boulder. Several trees…power poles…and power lines were downed…causing a number of outages as well as sparking a few small grass fires. Highest wind gusts reached 112 mph atop Niwot Ridge near the continental divide west of Boulder…102 mph at Wondervu…100 mph at the National Center for Atmospheric Research mesa lab in Boulder…98 mph at the national wind technology center near Broomfield…96 mph on Rocky Flats…92 mph at Jefferson County Airport near Broomfield and on the University of Colorado campus in Boulder…and 90 mph at Highlands Ranch in southwest metro Denver. Winds gusted to 48 mph at Denver International Airport.


In 1950…strong southwest winds gusting to 58 mph reduced the visibility to 1 mile in blowing dust at Stapleton Airport. Scattered minor wind damage…consisting of falling tree branches and damage to signs…occurred across metro Denver.

In 1989…6 to 12 inches of snow fell at many locations in the Front Range foothills. Boulder received 6 to 8 inches. Five inches (5.0 inches) of snow fell at Stapleton International Airport…causing 2 hour flight delays. I-25 south of Denver was closed for 4 hours due to a 100- car traffic pileup. North winds gusted to 33 mph at Stapleton International Airport where the maximum snow depth on the ground was only 3 inches due to melting.


In 1900…rain changed to heavy snow and totaled 6.8 inches in downtown Denver overnight. A thunderstorm occurred on the 9th. North winds were sustained to 32 mph with gusts to 38 mph on the 10th. Precipitation totaled 1.39 inches.

In 1933…post-frontal heavy snowfall totaled 9.4 inches in downtown Denver. East winds were sustained to 21 mph with gusts to 22 mph on the 9th.

In 1944…7.0 inches of snow fell on downtown Denver. Northeast winds were sustained to 24 mph on the 9th.

In 1977…the two warmest days of the month resulted in two temperature records being set. High temperature of 81 degrees on the 9th set a new record maximum for the date. High temperature of 80 degrees on the 10th equaled the record maximum for the date. The unusually warm weather for so early in April produced a late afternoon thunderstorm on the 10th.

In 1993…strong downslope winds occurred along the Front Range. While the strongest winds were in the foothills north of Denver…wind gusts to 69 mph were recorded at Jefferson County Airport in Broomfield. Northwest winds gusted to 39 mph at Stapleton International Airport.

In 2004…a spring storm brought heavy snow to metro Denver. The heaviest snow fell in the foothills and over and near higher terrain. Snowfall totals included: 20 inches near Jamestown; 18 inches atop gold hill; 17 inches near Evergreen; 15 inches at Nederland and Eldora; 13 inches at Blackhawk; 11 inches at Aspen Springs; 9 inches in Louisville; 8 inches at Ken Caryl; 6 inches at Niwot… Near Sedalia…and in Thornton; 5 inches in Lakewood… Lyons…and Westminster. Snowfall was 4.4 inches at Denver Stapleton. Northwest winds gusted to 21 mph at Denver International Airport.

In 2008…a very moist storm brought heavy snow to parts of the Front Range foothills. Storm totals included: 12.5 inches at Aspen Springs…11 inches…4 miles west- southwest of conifer; with 10.5 inches…3 miles north of central city and 6 miles southwest of Evergreen. Lesser amounts of 5 to 9 inches were observed elsewhere. North winds gusted to 43 mph at Denver International Airport on the 10th…and 1.8 inches of snow fell at the former Stapleton International Airport.

9-11 » Click here to read the rest of April 8 to April 14: This week in Denver weather history

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Thornton’s weekend to offer unsettled weather conditions, chance for snow

Friday, April 6th, 2018 5:32am MDT

Not a particularly great three-day period in terms of the weather ahead. The good thing is that we will receive some much-needed precipitation but overall conditions will be less than ideal.

Friday will be the most active weather day of the period. A cold front will be moving in this morning and that will result in our high temperature being seen early on and the mercury falling from there. Temps will be down to around the freezing mark by the afternoon rush hour. Winds will be breezy and out of the northeast for much of the day, skies mostly cloudy. As for precipitation, a few light rain showers may occur in the morning with the afternoon bringing our best chance for moisture, some of which should fall as snow. Less than an inch of accumulation is expected and that should only stick to grassy areas.

Tonight, any snow will end by midnight and lows will drop to the mid-20s.

Saturday will be the most pleasant day of the weekend. Temperatures will be right near the normal high of 59 degrees but we will see a good bit of clouds.

Tomorrow evening through Saturday night we see a chance for some light rain showers.

The rain will come to an end Sunday morning and skies will clear off giving mostly sunny skies Sunday. Temperatures will be near normal however we do expect breezy northwest winds throughout the day.

Have a great weekend!

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Thornton’s Thursday to bring unseasonably warm temps, calm conditions

Thursday, April 5th, 2018 5:09am MDT

Today’s weather looks to be a good bit like yesterday’s with temps above normal but also with some cloud cover. Tonight things change though as a front offers up colder temps and chances for snow Friday.

For today, we start out with mostly sunny skies then expect to see cloud cover increase by mid-morning. By this evening we will have partly sunny skies above.

Temperatures start up relatively warm then will climb toward a high in the mid to upper 60s. How high they go may very well be dependent on the cloud cover. If the expected wave cloud is particularly thick, it may suppress temperatures below the forecasted high.

Tonight, look for mostly cloudy skies above with lows in the mid-30s.

The pre-dawn hours Friday morning bring us a chance for a sprinkle of rain then we could see some light snow during the day tomorrow. At this time though, we are not expecting much, if any, accumulation. How does the weekend weather look? Get a sneak peek here.

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Warmer than normal temps, a good bit of clouds for Thornton’s Wednesday

Wednesday, April 4th, 2018 5:44am MDT

Not too bad of a day of weather ahead for us. The winds will ease and it will be warmer however with a good bit of moisture aloft, there will also be some cloud cover.

The day starts with partly clear skies and you can expect more of the same throughout the day with a bit thicker coverage in the late afternoon and tonight. Winds will be out of the northwest and just a little bit breezy in the afternoon. Temperatures start out chilly but then will improve with highs in the mid-60s, a respectable amount above the average of 59 degrees for the date.

Tonight, the cloud cover will remain until just before dawn tomorrow. Overnight low temps will dip to around the 40 degree mark.

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Tuesday to offer cool temps, sunny skies and a good dose of wind

Tuesday, April 3rd, 2018 5:02am MDT

We will see a bit of change in the weather today courtesy a cold front and trough. Temperatures are going to be considerably cooler than yesterday and we will have blustery conditions.

Sunny skies start things off and we will see more of the same throughout the day with few clouds. Temperatures will be about 25 degrees cooler than yesterday with highs topping out around 50 degrees.

The wind will be the biggest weather factor today, particularly this morning. Gusts to 40mph or so will be possible initially then we do see some easing in the afternoon although it will still be breezy.

Tonight, cloud cover increases and lows will dip to the mid to upper 20s.

Keep an eye on those wind speeds with our live weather gauges.

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March 2018 weather recap: A warmer, wetter than normal month

Monday, April 2nd, 2018 6:00am MDT

The month was one largely bereft of any true weather drama.  It started out quite warm and dry and while we chilled out and got wetter for the second half, there were no significant events of note.

The first couple of weeks of March were notable for their largely warmer than normal temperatures and their lack of precipitation. It wasn’t until the 15th when we finally saw some moisture.

The latter half of the month did turn largely cooler although there was a period from the 21st to the 25th with unseasonably warm mercury readings.  Beyond that, things remained cool and we received a few, minor shots of snow and rain.

In the end, the average temperatures for the month were above normal and while snowfall was less than normal, we recorded above average levels of precipitation.

The overall average temperature in Thornton for the month was 42.6 degrees.  This was a good bit above Denver’s long term average for the month of 40.4 degrees. In the Mile High City at Denver International Airport where official measurements are kept, a similar average of 42.7 degrees was seen.

Temperatures in Thornton ranged from a maximum of 74.2 degrees on the 22nd down to a low of 16.6 degrees on the 7th.  At DIA, the warmest reading was 73 degrees and the coldest 13 degrees, both on the same days as our warmest / coldest readings.

In terms of precipitation, Thornton saw 1.25 inches of liquid precipitation. Denver lagged us with 1.02 inches.  Both measurements, however, were above the March long term average of 0.92 inches.

March is usually one of our snowier months with an average of 10.7 inches recorded during the month. We fell a long ways short of that however with Thornton seeing 6.2 inches of the white stuff and Denver only 4.8 inches.

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

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

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

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

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

840 AM MDT SUN APR 1 2018




                 VALUE   DATE(S)  VALUE   FROM    VALUE  DATE(S)
 HIGH              84   03/26/1971
 LOW              -11   03/28/1886
HIGHEST            73   03/22        84     -11       81  03/18
LOWEST             13   03/07       -11      24       14  03/01
AVG. MAXIMUM     58.5              54.4     4.1     64.0
AVG. MINIMUM     26.8              26.4     0.4     31.9
MEAN             42.7              40.4     2.3     47.9
DAYS MAX >= 90      0               0.0     0.0        0
DAYS MAX <= 32      0               1.9    -1.9        0
DAYS MIN <= 32     27              23.6     3.4       16
DAYS MIN <= 0       0               0.1    -0.1        0

 MAXIMUM         4.56   1983
 MINIMUM         0.03   2012
TOTALS           1.02              0.92    0.10     0.90
DAILY AVG.       0.03              0.03    0.00     0.03
DAYS >= .01         6               5.9     0.1        6
DAYS >= .10         3               2.4     0.6        3
DAYS >= .50         0               0.3    -0.3        0
DAYS >= 1.00        0               0.1    -0.1        0
 24 HR. TOTAL    0.33   03/18 TO 03/18           03/24 TO 03/24

         OBSERVED                 NORMAL  DEPART  LAST YEAR`S

TOTALS            4.8              10.7

HEATING TOTAL     684               763     -79      523
 SINCE 7/1       4741              5202    -461     4325
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              11.5

AVERAGE SKY COVER           0.50
NUMBER OF DAYS FAIR            8
NUMBER OF DAYS PC             22


THUNDERSTORMS             1   MIXED PRECIP           2
HEAVY RAIN                0   RAIN                   5
LIGHT RAIN                5   FREEZING RAIN          0
LT FREEZING RAIN          0   HAIL                   0
HEAVY SNOW                2   SNOW                   4
LIGHT SNOW                7   FOG W/VIS <=1/4 MILE   2
FOG                       7   HAZE                   1

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