Thornton, Colorado, USA
UpdatedSun, 24-Mar-2019 9:25pm MDT 


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

Wednesday, October 10th, 2018 6:12am MDT
This week in Denver weather history

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

While fall has barely just begun, our look back at this week in Denver weather history is most notable for winter-like conditions. Numerous noteworthy storms have struck the Mile High City during this week in our past including a major one just seven years ago.

From the National Weather Service:


In 1903…north winds were sustained to 40 mph with gusts to 48 mph.

In 1917…post-frontal northwest winds were sustained to 45 mph with gusts to 52 mph. Rain was mixed with a trace of snow…the first of the season. Precipitation totaled 0.22 inch and included the occurrence of hail… Even though no thunder was heard.

In 1950…strong winds caused a power outage in Boulder. This was the heaviest windstorm since January. Damage was minor. Northwest winds gusted to only 35 mph at Stapleton Airport.

In 1985…strong Chinook winds buffeted the Front Range foothills. Wind gusts between 60 and 70 mph were reported in Boulder and atop squaw mountain west of Denver. Southwest winds gusted to 41 mph at Stapleton International Airport.


In 1990…the season’s first snow occurred. Snowfall amounts varied from 3 to 7 inches across metro Denver. Snowfall totaled 4.0 inches at Stapleton International Airport where north winds gusted to 29 mph.


In 1923…southeast winds were sustained to 44 mph with gusts to 47 mph. The strong winds persisted through the afternoon. The high temperature of 77 degrees was the warmest of the month that year.

In 1975…a wind gust to near 100 mph was recorded in Boulder. Frequent wind gusts to 60 mph were reported along the foothills causing only minor damage. West winds gusted to 45 mph at Stapleton International Airport.


In 1910…light smoke from forest fires in the mountains was sighted over the city.

In 1982…northwest winds gusted to 49 mph at Stapleton International Airport.


In 2005…a major winter storm brought heavy…wet snowfall to the Front Range mountains…eastern foothills…portions of metro Denver…and the Palmer Divide. Snow accumulations ranged from 8 to 26 inches with drifts from 3 to 4 feet in places. The heaviest snow occurred to the east and southeast of the city…closing most major highways in that area…including I-70 from Denver to Limon. The Red Cross opened four shelters for people who were stranded along I-70 in eastern Colorado. Since many trees had not yet shed their leaves…the storm caused significant tree damage. One woman in Denver was killed when a tree branch… 8 to 10 inches in diameter…snapped under the weight of the heavy…wet snow and struck her as she was shoveling her driveway. Xcel Energy reported power outages to about 35 thousand customers. Several incoming flights were delayed at Denver International Airport. Snow totals included: 16 inches in the foothills near Boulder…12 inches at Genesee and near Golden…22 inches near Watkins…19 inches near Bennett…17 inches southeast of Aurora…14 inches near Parker…13 inches near Castle Rock…12 inches in Centennial… 11 inches in Parker…and 10 inches at Denver International Airport and in Littleton. While many areas of metro Denver received heavy snow…others experienced almost entirely rain. This included west and northwest metro Denver…Boulder…and Longmont. Rainfall amounts were significant as storm totals ranged between 1.50 and 2.50 inches. The steady rainfall triggered 3 rockslides in foothills canyons. Two of the slides occurred on State Highway 119 in Boulder Canyon and the longest slide…7 feet in length…on State Highway 74 in Bear Creek Canyon at Idledale. North winds were sustained to around 23 mph with gusts to 31 mph at Denver International Airport on the 9th. The high temperature of only 34 degrees on the 10th was a record low maximum for the date. The low temperature on both days was 32 degrees.


In 1901…an evening thunderstorm produced east winds to 43 mph with gusts to 48 mph.

In 1949…strong winds believed to be the worst in Boulder’s history at the time caused over 100 thousand dollars damage in the city. Peak winds were estimated to 85 mph at Valmont…just east of Boulder. High winds also occurred over most of metro Denver and caused damage to trees…window glass…and utility lines. The damage was most pronounced over the northwest metro area…including north Denver and Lakewood. Falling tree branches caused damage to parked autos and houses. Wind gusts to 70 mph were recorded at Stapleton Airport.

In 1964…lightning struck and killed a 13-year-old boy…while he was riding his bicycle along a tree-lined residential street in south Denver. Apparent microburst winds gusted to 54 mph at Stapleton International Airport.


In 1986…the first significant snowstorm of the season produced 2 to 5 inches of snow over metro Denver with 5 to 10 inches in the foothills west of Denver. Wondervu recorded the most snow from the storm…13 inches. The heavy wet snow caused numerous power outages. The storm was accompanied by strong north winds with gusts to 41 mph recorded on the 10th. The first snowfall of the season totaled 3.1 inches at Stapleton International Airport with only one inch on the ground due to melting. The strong cold front accompanying the storm cooled the temperature from a high of 73 degrees on the 10th to a high of only 33 degrees on the 11th…which was a record low maximum for the date.


In 1969…the second heavy snowstorm in less than a week dumped nearly a foot of snow across metro Denver and plunged the area into extremely cold temperatures for so early in the season. Snowfall totaled 11.0 inches at Stapleton International Airport. North winds gusting to 26 mph produced drifts up to 2 feet deep. Temperatures dipped from a high of 52 degrees on the 10th to a record low for the date of 10 degrees on the 12th. There was additional damage to trees and power and telephone lines from heavy snow accumulations and icing. Travel was restricted or blocked by drifting snow in both the mountains and on the plains east of Denver.

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

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Wednesday to continue the cold temperatures and damp conditions, just a slight chance for snow

Wednesday, October 10th, 2018 5:11am MDT

Not a lot of improvement in Thornton’s weather for today as well below normal temps coupled with drizzle and light rain will remain. By the end of the day though, we may see just a bit of sun start to peek out.

Cloudy skies start things off and will persist through the morning and early afternoon. After that, a few breaks in the coverage may be seen although not a lot.

Drizzle and light rain will continue to occur off and on into mid to late afternoon. A little bit of snow may get mixed in there but with only minimal accumulations if any at all.

Temperatures will push close to the 40 degree mark, still well below what we would expect to see this time of year.

Tonight, mostly cloudy skies will be above with lows dipping toward the freezing mark.

Keep an eye on the thermometer here.

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Cool, damp conditions to remain for Tuesday, Freeze Warning issued

Tuesday, October 9th, 2018 5:04am MDT

Not much change in our weather today versus yesterday although overall we expect less precipitation. Temperatures will remain well below normal and tonight we could see that first hard freeze of the season.

Cloudy skies are going to be the rule today and we don’t see any real chance for a break in the cloud cover. Drizzle and fog will be seen early then look for a return of drizzle / showers in the afternoon and evening. Highs today will top out in the low 40s, this in comparison to the average high for the date of 68 degrees.

Tonight, cloudy skies will be above with just a bit of clearing after midnight. We may see some snow mix in with the overnight showers but without any accumulation. Lows will dip to near the 30 degree mark although with the cloud cover we may fail to see that freezing reading.

A Freeze Warning has been issued just in case and is in effect from 6:00pm this evening to 10:00am tomorrow.

Stay warm and dry!

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Thornton’s workweek starts cold and wet, may bring first freeze & snow of the season

Monday, October 8th, 2018 5:09am MDT

Mother Nature is set to bring us a pretty significant change in the weather. Today will see temps well below normal with rain for much of the day and then tonight we are expecting our first freeze of the season and perhaps some snow.

Cloudy skies are going to be the rule through today and tonight. Light rain will be seen throughout much of the day before easing in the late afternoon. A few flakes of snow may get into the mix but nothing that will accumulate.

Temperatures will remain steady and in the mid to upper 30s during the daytime hours. As temperatures drop this evening and overnight tonight, some snow may get into the mix but we aren’t expecting any accumulations.

Overnight lows tonight will dip to 30 degrees or so. This has prompted a Freeze Watch to be issued and appropriate precautions should be taken. Be sure your hoses are disconnected from the house, swamp coolers and sprinklers are disconnected and drained and any sensitive vegetation is covered or brought inside.

Stay warm today!

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Thornton’s weekend weather to offer cool temperatures, unsettled conditions

Friday, October 5th, 2018 4:59am MDT

A series of disturbances is going to give this weekend’s weather a distinctly fall feel to it. It starts out relatively nice Friday morning but from there temperatures cool and we will see chances for showers.

For today, mostly sunny skies kick things off but cloud cover will be increasing as the day progresses and a cold front approaches. Highs will top out in the mid to upper 60s but be cooling by mid-afternoon. Some light showers may be seen this afternoon and evening into tonight. Overnight tonight, mostly cloudy skies will be above with lows dipping to the mid to upper 30s.

On Saturday we will be feeling the effects of colder air from the north. Highs will be in the mid-50s under mostly cloudy skies. We should remain dry though. Overnight Saturday night into Sunday morning, skies will remain mostly cloudy with lows dipping to around 40 degrees.

Sunday will be most unsettled day of the period. Mostly cloudy skies will be above throughout. A few sprinkles of rain will be possible in the morning with coverage spreading in the afternoon and evening. Highs will be in the mid-50s.

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Our first freeze and snow could come at any time

Thursday, October 4th, 2018 5:56pm MDT

While we enjoyed a nice day today with temperatures a good bit above normal, it might be time to start thinking about snow and cold. While we don’t have any freezing temps or any of the white stuff in the immediate forecast, history shows us it could happen any time now. You may start thinking about getting those sprinklers blown out, swamp coolers put away and other winterization tasks done.

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Thornton’s October weather preview: Fall arrives, usually with the first freeze and snow

Thursday, October 4th, 2018 5:00pm MDT

Thornton, Colorado October weather preview.With the first full month of fall here, October usually brings one of the quietest weather months in the Denver area with plenty of mild, sunny days and clear, cool nights.

October is historically the second sunniest month and conditions are generally calm.

However we also will usually see our first taste of winter during the month with the first freeze and first snowfall of the season.

Temperatures as well will start to drop and by the end of the month the average nighttime lows are below freezing.

For complete details on our historical October weather and what we can expect in the coming month, read our complete October weather preview here.

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September 2018 weather recap: Warmer than normal but near average precipitation

Thursday, October 4th, 2018 4:50pm MDT

High pressure was a recurring theme for the month of September in 2018.  This was the driving force behind many days with above normal temperatures and a mere three days with precipitation.

The ridge seemed to show little movement in the month keeping moisture at bay and any cooler air to the north. The middle of the month in particular bore the brunt of this feature when we saw a string of nine days of 90 degree or higher readings.

Thornton’s average temperature for the month came in at 64.8 degrees.  Denver’s long term average for the month is 63.4 degrees so we were a good bit above that.

Out at DIA where the Mile High City’s official measurements are kept, it was considerably warmer with an average this year 67.8 degrees. That puts the month in the books as the sixth warmest September on record – with the asterisk that should always comes with Denver’s stats since the station moved to the airport.

Thornton saw its warmest temperature of 94.4 degrees on the 16th of the month and its coldest of 35.3 degrees on the 29th.  Denver saw its maximum for the month of 96 degrees on the 13th and its coldest reading of 36 degrees on the 29th.

Officially, Denver saw four records tied or broken.  On the 10th the record high of 93 degrees was tied, a 93 degree reading on the 11th broke the record high for the date and a high of 94 degrees on the 14th was tied the record high. Lastly, a record high minimum of 64 degrees was set on the morning of the 13th.

In terms of precipitation, Denver averages 0.96 inches during September.  In Thornton, we saw 1.02 inches fall in the bucket with virtually all of that coming on two days. Denver was much drier with only 0.18 inches.

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

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

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

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

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

303 PM MDT MON OCT 1 2018




                 VALUE   DATE(S)  VALUE   FROM    VALUE  DATE(S)
 HIGH              97   09/03/2017
 LOW               17   09/29/1985
HIGHEST            96   09/13        91       5       97  09/03
LOWEST             36   09/29        35       1       40  09/20
AVG. MAXIMUM     82.7              78.5     4.2     79.0
AVG. MINIMUM     52.8              48.3     4.5     51.3
MEAN             67.8              63.4     4.4     65.1
DAYS MAX >= 90      9               3.4     5.6        9
DAYS MAX <= 32      0               0.0     0.0        0
DAYS MIN <= 32      0               0.8    -0.8        0
DAYS MIN <= 0 0 0.0 0.0 0 PRECIPITATION (INCHES) RECORD MAXIMUM 5.61 2013 MINIMUM T 1892 1944 TOTALS 0.18 0.96 -0.78 1.26 DAILY AVG. 0.01 0.03 -0.02 0.04 DAYS >= .01         5               6.5    -1.5        6
DAYS >= .10         0               3.3    -3.3        2
DAYS >= .50         0               0.6    -0.6        1
DAYS >= 1.00        0               0.1    -0.1        0
 24 HR. TOTAL    0.08   09/19

 TOTAL            0.0
 TOTAL           17.2  1971         1.3

HEATING TOTAL      69               125     -56      122
 SINCE 7/1         78               141     -63      130
COOLING TOTAL     160                76      84      131
 SINCE 1/1       1022               764     258      880

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

AVERAGE WIND SPEED              9.7

AVERAGE SKY COVER           0.40
NUMBER OF DAYS FAIR           13
NUMBER OF DAYS PC             13


THUNDERSTORMS             5   MIXED PRECIP           0
HEAVY RAIN                0   MODERATE RAIN          0
LIGHT RAIN                9   FREEZING RAIN          0
LT FREEZING RAIN          0   HAIL                   0
HEAVY SNOW                0   SNOW                   0
LIGHT SNOW                0   FOG W/VIS <=1/4 MILE   3
FOG                       5   HAZE                   2

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Thornton’s Thursday to offer cool temps, slight chance for showers

Thursday, October 4th, 2018 5:28am MDT

Following the cold front that moved through yesterday evening, our day starts out a bit unsettled. By this afternoon though, skies will be clearing, albeit with a lingering chance for a shower.

Cloudy skies start off the day then by mid-morning we will begin to clear with mostly sunny skies arriving for the afternoon and evening. A few drops of rain might fall this morning with a bit better chance of an isolated shower in the afternoon. Temperatures cool a good bit today with highs expected to top out in the mid-60s.

Tonight, skies will continue to clear with lows in the mid-40s.

Keep an eye out for any showers here.

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Unseasonably warm temps for Wednesday; cooler, wetter weather arrive tonight

Wednesday, October 3rd, 2018 5:03am MDT

Thornton will get a mild day today with a slight chance for a PM storm. Tonight though, a system moves through with decent chances for rain and signifies a change in the overall patter which will see us cool down a good bit for the foreseeable future.

For today, mostly sunny skies will be above for much of the day with cloud cover increasing in the mid to late afternoon through tonight. Winds will initially be calm then become breezy by late morning and lasting into the evening as the system moves in. Temperatures will top out near the 80 degree mark, well above the average high of 71 degrees for the date.

Late afternoon may see a shower / thunderstorm pop up with chances for showers increasing as we get closer to sunset and then lasting through much of the night. There is not, however, a lot of moisture with the system so while we do believe we will see some rain, it isn’t expected to amount to a whole lot.

Looking ahead, Thursday and Friday will cool to levels a bit below normal. After that, we see even cooler temperatures with better chances for precipitation. By early next week, we could be looking at our first snow of the season although right now, it looks like if it happens, it wouldn’t be much. Keep an eye on our extended weather forecast for more.

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