Thornton, Colorado, USA
UpdatedSun, 24-Mar-2019 9:20pm MDT 


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Thornton’s weekend starts cold and wet, will then dry out but remain chilly

Friday, January 11th, 2019 5:04am MDT

Finally some much-needed moisture! We will see precipitation through the day today into tonight but then will dry out for Saturday and Sunday while remaining colder than normal.

For Friday, temps are starting out warmer than expected leading to more rain than snow. However, we do believe the air mass will cool giving us the white stuff. The ground is quite warm so any daytime accumulation will be confined to grassy areas.

As it continues into tonight though, some may start sticking to the roads. Total accumulations of a couple of inches are possible, perhaps more depending on the rain / snow mix and transition. A Winter Weather Advisory remains in effect until midnight.

Tonight, precipitation will taper off after midnight, ending before dawn tomorrow. Lows tonight will be in the mid-20s.

Saturday looks to be a relatively nice day albeit with some clouds and cool temps. Look for partly sunny skies above with highs in the upper 30s. Saturday night into Sunday, partly clear skies will be above with lows dropping to around 20 degrees.

Closing out the weekend, Sunday will bring mostly clear skies. Temps remain colder than normal with highs in the upper 30s.

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Thornton’s Thursday to offer one more day with unseasonably warm temps

Thursday, January 10th, 2019 5:10am MDT

A pretty good looking day ahead for us with temperatures once again well above normal. Change is on the way though with cold and snow in the forecast for Friday.

Today starts out with mostly clear skies and we should see a good bit of blue above for much of the day. The afternoon is expected to bring a bit of an increase in cloud cover though. Temperatures will be topping out in the mid-50s with generally calm conditions.

Tonight, skies will be partly clear initially with increasing cloud cover through the night. Overnight lows will be in the mid to upper 20s.

A cold front will be arriving tonight and with it, an increase in moisture. Some light rain / snow will be possible after midnight.

The main part of the coming storm arrives around dawn tomorrow and will impact us for much of tomorrow. Temperatures will be much colder and we should see some accumulating snowfall. Models are highly varied on their solutions right now but the potential is there for Thornton to get an inch or two.

Enjoy today’s warm weather and keep an eye on http://www.thorntonweather.com for all the latest.

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Wednesday brings more clouds but warmer temperatures

Wednesday, January 9th, 2019 5:03am MDT

Not too bad of a day ahead for Thornton as the mild conditions will continue. There will, however, be more cloud cover above.

We start out with partly clear skies and can expect more of the same throughout the day. Overall conditions will be calm, winds light. Temperatures will top out in the low 50s, above the average high for the date of 44 degrees.

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

Looking ahead, we’ll enjoy another mild day tomorrow then a glancing blow from a passing storm could bring some light snow Friday. More in the extended weather forecast here.

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January 6 to January 12: This week in Denver weather history

Tuesday, January 8th, 2019 8:15am MDT
This week in Denver weather history

January 6 to January 12: This week in Denver weather history

Extreme cold would be the first thing to come to your mind when you think of January. While there have been many such notable events of that nature, our look back at this week in Denver weather history actually is more remarkable for the damaging wind that has raked the area in the past.

From the National Weather Service:


In 1973…the 31st marked the start of a protracted cold spell that extended into January of 1974 when temperatures dipped below zero on 7 consecutive days. Record daily minimum readings occurred on the 3rd and 5th when the temperature plunged to 17 degrees below zero on both days. A record low daily maximum temperature of only 4 degrees occurred on the 5th.


In 1941…a protracted cold spell through January 7…1942… Produced below zero low temperatures on 7 of the 8 days. A low temperature of 2 degrees on the 3rd prevented a string of 8 days below zero. The coldest days during the period were the 1st with a high of 2 degrees and a low of 9 degrees below zero…the 4th with a high of 2 degrees and a low of 11 degrees below zero…and the 5th with a high of 26 degrees and a low of 12 degrees below zero.


In 1940…snowfall totaled 5.9 inches in downtown Denver.

In 1975…high winds gusting to over 75 mph caused considerable damage in the Boulder area and minor damage in Jefferson County.

In Boulder…one home was unroofed… Several power lines were blown down…and a number of homes and commercial buildings were damaged. Northwest winds gusted to 36 mph on the 5th and 38 mph on the 6th at Stapleton International Airport.

In 1980…high winds in and near the foothills shattered windows…tore roofs from buildings…and caused many power outages. Much of the damage was in Boulder…where winds gusted to at least 82 mph. Wind gusts of 80 to 100 mph were common in the foothills. West winds gusted to only 37 mph at Stapleton International Airport on the 6th.

In 1982…2 to 6 inches of snow fell across metro Denver. Only 1.1 inches of snow were measured at Stapleton International Airport.

In 1983…high winds buffeted the foothills with gusts of 60 to 75 mph recorded in the Boulder area. West winds gusted to only 38 mph at Stapleton International Airport on the 6th.

In 1998…heavy snow blanketed the Front Range foothills. Snowfall totals included: 15 inches 8 miles north of Blackhawk; 13 inches at Evergreen and 5 miles east of Nederland; 12 inches in Coal Creek Canyon; 11 inches 8 miles west of Conifer; 10 inches in sunshine canyon northwest of Boulder; 10 inches 11 miles southwest of Morrison; 9 inches in south turkey canyon; and 8 inches at Eldora Ski Area. Snowfall totaled only 1.8 inches at the site of the former Stapleton International Airport.


In 1903…northwest winds were sustained to 45 mph with an extreme velocity of 48 mph. The Chinook winds warmed the temperature to a high of 66 degrees…which was a record maximum for the date. The low temperature dipped to only 35 degrees.

In 1962…strong winds caused nearly 14 hundred dollars in damage 2 miles north of Boulder. West-northwest Chinook winds gusted to 33 mph at Stapleton Airport in advance of a cold front that produced northeast wind gusts to 43 mph along with some blowing dust and 0.1 inch of snow.

In 1972…a wind gust to 69 mph was recorded at the National Bureau of Standards in Boulder. Only minor damage occurred. Northwest winds gusted to 33 mph at Stapleton International Airport.

In 2007…a large avalanche swept two vehicles off U.S. Highway 40…near Berthoud Pass…and partially buried them. The slide covered all three lanes of the highway. Eight people were in the vehicles…but only one person was seriously injured. He suffered several broken ribs. The slide was approximately 200 feet wide and 15 feet deep.


In 1908…furious high winds were noted in Boulder but caused only minor damage and injury.

In 1913…a very cold arctic air mass caused temperatures to plunge to record levels. The low temperature fell to 21 degrees below zero on the 6th and to 18 degrees below zero on the 7th…both records. The high temperature of only 8 degrees below zero on the 6th was a record low maximum for the date.

In 1920…post-frontal heavy snowfall totaled 7.0 inches in downtown Denver. North winds were sustained at 24 mph with gusts to 30 mph on the 6th.

In 1923…warm Chinook winds resulted in two temperature records. Low temperatures of 37 degrees on the 6th and 42 degrees on the 7th equaled the record high minimums for the dates. West winds were sustained to 30 mph with gusts to 33 mph on the 6th. Southwest winds were sustained to 47 mph with gusts to 52 mph on the 7th. High temperatures were 53 degrees on the 6th and 56 degrees on the 7th.

In 1986…2 to 4 inches of snow fell over metro Denver… With 5 to 8 inches in the foothills west of the city. The 2.4 inches of snowfall recorded at Stapleton International Airport was the only snowfall of the month. Northwest winds gusted to 24 mph at the airport.

In 2006…a brief warm spell resulted in two temperature records. High temperatures of 66 degrees on the 6th and 69 degrees on the 7th equaled the record daily maximum temperatures for each of those days. Low temperatures remained above freezing and were within 1 or 2 degrees of the record daily high minimums.


In 1911…west Chinook winds were sustained to 51 mph and warmed the temperature to a high of 56 degrees.

In 1994…occasional high winds buffeted the eastern foothills. Wind gusts to 99 mph were recorded at Rollinsville…southwest of Boulder. West winds gusted to 40 mph at Stapleton International Airport.

In 1995…a brief blast of high winds hit the eastern foothills and adjacent Front Range communities. A wind gust to 112 mph was recorded atop Squaw Mountain…west of Denver. In Boulder…winds gusted to 81 mph. West winds gusted to 31 mph at Stapleton International Airport.

In 2009…damaging downslope winds were responsible for triggering two wildfires that threatened the city of Boulder. Peak wind gusts ranged from 75 to 107 mph in and near the foothills of Boulder…Jefferson and Park counties. Although the fires never merged…they were close enough for firefighters to build a perimeter around both of them. The fires quickly torched 3000 acres and forced the evacuation of up to 1400 families. One home was destroyed along with several barns and outbuildings. Three firemen suffered minor injuries. In Bailey…power lines were downed by falling trees. A tin roof on an auto repair shop in town was almost completely blown off. Peak wind gusts included: 107 mph…3 miles south of Mt. Audobon…92 mph…3 miles south of Evergreen; 87 mph…6 miles northwest of Boulder; 81 mph…2 miles east-northeast of Bergen Park and at the National Wind Technology Center; 79 mph…4 miles northeast of Nederland; 77 mph…3 miles west of Sheridan; 75 mph at Genesee. A peak wind gust of 39 mph was measured at Denver international Airport from the west.


In 1911…gale force winds occurred in Boulder causing minor injuries.

In 1937…cold arctic air plunged temperatures below zero for an estimated 56 consecutuve hours. Two temperature records were set. High temperatures of 8 degrees below zero on the 7th and 3 degrees on the 8th were record low maximum readings for those dates. Low temperatures plunged to 12 degrees below zero on the 7th and 11 degrees below zero on the 8th. Snowfall was 1.4 inches in downtown Denver.

In 1969…a violent evening windstorm struck Boulder and the adjacent foothills. A wind gust to 130 mph was recorded at the National Center for Atmospheric Research. Winds reached 96 mph in downtown Boulder. The Boulder airport wind recorder was blown away after measuring a wind gust to 80 mph. The windstorm caused over one million dollars in damage and one fatality in Boulder. About 25 homes in south Boulder had roofs blown off or were severely damaged. Roofs were blown off buildings housing scientific laboratories and offices of the Environmental Science Services Administration…now NOAA…in Boulder…and installations of several scientific measuring sites near Boulder received heavy damage. Grass fires driven by the high winds endangered many areas…but were controlled by volunteer firemen. One man died from injuries received when he was blown from a fire truck. One man was killed and another injured when the truck camper in which they were riding was blown off I-25 about 10 miles north of Denver. In the same area a mobile home and a truck trailer were blown off the highway and demolished. At least 20 people in the Boulder area received light to serious injuries from flying debris or from being blown into obstructions. Power lines and trees were downed over a wide area. Damage was relatively light in the city of Denver…where northwest winds gusted to 62 mph at Stapleton International Airport on the 8th. Many windows were broken in Arvada…Englewood…and Littleton. A 27-year-old fire lookout tower on Squaw Mountain…west of Denver…was blown away…and several radio relay towers at that location were toppled. Trucks were overturned near Georgetown. Mobile homes were overturned in several areas with occupants receiving injuries in some cases. The strong Chinook winds also brought warm weather. The maximum temperature of 69 degrees on the 7th broke the old record of 65 degrees set in 1948. The temperature also reached 65 degrees on the 8th…but was not a record.

In 1992…an intense blizzard buried eastern parts of metro Denver. At times snow fell at rates of 2 to 3 inches an hour. Winds increased from the north at speeds of 25 to 45 mph. Drifts of 4 to 8 feet were common. I-70 was closed east of Denver…and I-25 was closed from Denver south. Snowfall totals ranged from a couple of inches in the foothills west of Denver to as much as 2 feet on the east side of metro Denver. The heaviest snow fell on the 7th in a band from the northern suburbs of Westminster and Thornton through Aurora and east Denver to southeast of Parker. Snowfall totals included: 22 inches in southeast Aurora…14.8 inches at Stapleton International Airport…13 inches in Northglenn…10 inches in Parker…and 9 inches in Westminster. The 14.5 inches of snowfall measured on the 7th into the 8th is the greatest 24 hour snowfall ever recorded in the city during the month of January. North winds gusting to 46 mph caused much blowing snow at Stapleton International Airport.

In 2000…high winds developed in and near the Front Range foothills. The strongest winds were generally confined to foothills areas north of I-70. A wind gust to 76 mph was reported in Golden Gate Canyon. West winds gusted to 37 mph at Denver International Airport on the 8th.


In 1962…a major winter storm dumped 13.5 inches of snow on metro Denver. A foot of the snow fell on the 8th when northeast winds gusted to 30 mph. The storm was followed by an intense blast of very cold arctic air. Minimum temperature readings of 24 degrees below zero occurred on both the 9th and 10th. The temperature never reached above zero on the 9th when a maximum reading of 1 degree below zero was recorded. Temperatures were below zero for 37 consecutive hours.

» Click here to read the rest of January 6 to January 12: This week in Denver weather history

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Temps a bit above normal, lots of sun, far less wind for Tuesday

Tuesday, January 8th, 2019 5:09am MDT

A very pleasant winter day ahead for Thornton. With sunny skies above, temps will be above normal most notably, winds will be calm as compared to yesterday.

Clear skies start things off and will continue through the day. There may be a cloud here and there but they won’t be amounting to much. Temperatures will top out close to 50 degrees, about 5 degrees above normal. Winds will generally be calm.

Tonight, partly cloudy skies will be overhead with lows dipping to the low 20s.

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Thornton’s workweek starts with warm temps but a good dose of wind

Monday, January 7th, 2019 5:01am MDT

Somewhat of a mixed bag of weather for us today. While we will again enjoy temperatures well above normal, strong, west winds are going to dim any enjoyment of the warmth.

We start out with mostly clear skies and should have more of the same throughout the day today. Temperatures will be topping out in the low to mid-50s.

The main story will be the wind, some of which we saw overnight. Speeds will be increasing this morning, peaking in early to mid-afternoon. At their height, gusts to 50mph will be possible. We will see things settle down as we get close to sunset, then turn calm by about 10:00pm.

Tonight, skies will be mostly clear with lows in the mid-20s.

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

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Warm weather to last through the weekend, clouds on the increase

Friday, January 4th, 2019 5:02am MDT

We have a pretty nice three day period of weather ahead for Thornton. Temperatures will continue to be above normal although a passing system will bring more clouds as the weekend progresses.

Friday will be the warmest and sunniest of the three days. Look for sunny skies to dominate with just a few clouds in the afternoon. Conditions will be calm and dry with highs topping out in the mid to upper 50s. Tonight, skies remain mostly clear with lows dipping to the mid-20s.

Saturday starts out mostly clear then we will see cloud cover increase in the afternoon. Temperatures will be slightly cooler with highs in the mid-50s. Saturday night, mostly cloudy skies will be above with lows below the 30 degree mark.

The weekend closes out on Sunday with temps remaining mild but with a good bit of cloud cover. Highs will be in the low to mid-50s under mostly cloudy skies.

Have a great weekend!

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Thornton’s Thursday warms up nicely with lots of blue sky above

Thursday, January 3rd, 2019 4:59am MDT

Our rebound from the cold continues. Today, temps climb to a good ways above normal with sunny skies above.

Clear skies start us off and while there might be a small cloud or two later, they won’t amount to much. Temperatures will be topping out right near 50 degrees. The average high for the date is 43 degrees.

Tonight, mostly clear skies will be above with lows dropping to the low to mid-20s.

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December 2018 weather recap: Warmer and much drier than normal

Wednesday, January 2nd, 2019 5:36am MDT

Thornton’s December was lacking in terms of any sort of real weather drama. Temperatures were relatively mild for much of the month and precipitation was fleeting.

Above normal temperatures were the general rule for the first part of the month. It was only the last week of the month when Arctic air arrived and we saw temperatures drop considerably. We saw only two measurable snow events, neither of which amounted to much.

Overall, Thornton’s average temperature for the month was 30.8 degrees. This was nearly a full degree above Denver’s long term December average of 30.0 degrees. Out at DIA where the Mile High City’s official measurements are taken, it was a good bit warmer with an average of 32.5 degrees.

Temperatures in Thornton ranged from a high of 60.6 degrees on the 21st down to a low of 4.5 degrees on the morning of the 29th. Denver’s warmest reading of 63 degrees also came on the 21st and its coldest, 0 degrees, on the 31st.

Denver averages 0.35 inches of precipitation during December. Thornton fell well short with a mere 0.07 inches. Out at the airport, even less was realized with 0.03 being recorded. This puts December 2018 into the books as one of the driest Decembers ever recorded.

Ten driest December’s in Denver weather history (since 1872):
0.00 – 1881
TRACE – 1905
0.01 – 1906, 1895
0.03 – 1977, 1931, 2018
0.04 – 2004, 1890
0.05 – 2002, 1995

Thornton recorded a mere 0.9 inches of snow during the month, the majority of which fell on the last day of the month. Denver saw 0.5 inches, all on the 31st.  Both fall well short of the long term Denver average for December snowfall of 8.5 inches and put December 2018 on the list of the ten least snowy Decembers recorded.

Ten least snowy December’s in Denver weather history:
TRACE – 1905, 1906, 2002
0.1 – 1928
0.4 – 1890
0.5 – 1935, 2018
0.6 – 1995
0.7 – 1977, 1895

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

Thornton, Colorado's December 2018 Temperature Summary. (ThorntonWeather.com)

Thornton, Colorado’s December 2018 Temperature Summary. (ThorntonWeather.com)

Thornton, Colorado's December 2018 Precipitation Summary. (ThorntonWeather.com)

Thornton, Colorado’s December 2018 Precipitation Summary. (ThorntonWeather.com)

936 AM MST TUE JAN 1 2019




                 VALUE   DATE(S)  VALUE   FROM    VALUE  DATE(S)
 HIGH              79   12/05/1939
 LOW              -25   12/22/1990
HIGHEST            63   12/21        62       1       69  12/12
LOWEST              0   12/31        -4       4       -4  12/24
AVG. MAXIMUM     46.1              42.8     3.3     48.3
AVG. MINIMUM     18.8              17.1     1.7     18.0
MEAN             32.5              30.0     2.5     33.2
DAYS MAX >= 90      0               0.0     0.0        0
DAYS MAX <= 32      4               5.8    -1.8        4
DAYS MIN <= 32     31              29.4     1.6       28
DAYS MIN <= 0       1               2.0    -1.0        1

 MAXIMUM         5.21   1913
 MINIMUM         0.00   1881
TOTALS           0.03              0.35   -0.32     0.21
DAILY AVG.       0.00              0.01   -0.01     0.01
DAYS >= .01         1               4.1    -3.1        4
DAYS >= .10         0               1.1    -1.1        1
DAYS >= .50         0               0.1    -0.1        0
DAYS >= 1.00        0               0.0     0.0        0
 24 HR. TOTAL    0.03   12/31 TO 12/31

TOTALS            0.5               8.5

HEATING TOTAL     999              1086     -87      979
 SINCE 7/1       2372              2468     -96     2150
COOLING TOTAL       0                 0       0        0
 SINCE 1/1       1026               769     257      881

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

AVERAGE WIND SPEED              9.6

AVERAGE SKY COVER           0.50
NUMBER OF DAYS FAIR            6
NUMBER OF DAYS PC             22


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After a very cold start, Wednesday will warm to near normal, offer clear skies

Wednesday, January 2nd, 2019 5:03am MDT

Thornton starts out with some bone-chilling cold but we will see a decent bit of warming. Temps will end of near normal with lots of sun above.

Clear skies start things off and will continue through the day. You will hard pressed to find a cloud today. After a start in the single digits, temperatures should warm to within a couple of degrees of the average high of 43 degrees for the date.

Tonight, skies will remain clear with lows dipping to the teens.

Keep an eye on the temps here.

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