Thornton, Colorado, USA
UpdatedThu, 23-Nov-2017 3:15pm MST 


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A Look At Voyager’s 40 Year Journey

Wednesday, September 6th, 2017 7:52am MST

NASA’s Voyager 1 probe has been floating around uncharted space for 40 years now. It was launched on Sept. 5, 1977, followed by the launch of Voyager 2 a fortnight later. Together, these brave little space wanderers have traversed several light years to become earth’s most distant scouts. Being the only two man-made objects to ever… » Click here to read the rest of A Look At Voyager’s 40 Year Journey

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Irma is now the strongest Atlantic Ocean hurricane ever

Wednesday, September 6th, 2017 7:47am MST

Hurricane Irma roared into the Caribbean with record-setting force early Wednesday, shaking people in their homes on the islands of Antigua and Barbuda on a path toward Puerto Rico and possibly Florida by the weekend. Irma, which was the strongest Atlantic hurricane ever recorded north of the Caribbean and east of the Gulf of Mexico, passed… » Click here to read the rest of Irma is now the strongest Atlantic Ocean hurricane ever

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Wednesday warms back up offering seasonal temps, lots of sun

Wednesday, September 6th, 2017 5:07am MST

A very nice day ahead for Thornton. While we will continue to see a good bit of haze above, the sun will be out there and temperatures right near normal.

We start out the day under sunny skies and those will stick with us until late afternoon when just a few clouds arrive. This morning we saw our coolest temperature reading in two and a half months but we will rebound from that steadily. Highs today will top out right near the average for the date of 83 degrees.

Look for skies to remain mostly clear tonight with lows in the low to mid-50s.

Our webcams provide a view to the outside.

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Al Gore Outsold On Kindle By An E-Book Debunking ‘An Inconvenient Sequel’

Tuesday, September 5th, 2017 11:03am MST

Former Vice President Al Gore’s new book is lagging in sales, and, in fact, is being outsold on Amazon Kindle by an e-book debunking many of the claims made in “An Inconvenient Sequel.” Climatologist Roy Spencer authored an e-book “An Inconvenient Deception” to critique the “bad science, bad policy and some outright falsehoods” in Gore’s latest… » Click here to read the rest of Al Gore Outsold On Kindle By An E-Book Debunking ‘An Inconvenient Sequel’

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A hint of fall in the air for Thornton’s Tuesday

Tuesday, September 5th, 2017 5:19am MST

The cold front that moved through yesterday evening is going to bring about a welcome change to our weather. Considerably cooler temperatures will help to serve as a reminder that the change of seasons is approaching.

We start out the day with a healthy dose of cloud cover but that will ease as the morning progresses leading to mostly sunny skies in the afternoon. Winds will be light and out of the northeast. Temperatures today will be much cooler than in days’ past with highs only in the low to mid-70s.

Tonight, mostly clear skies should allow us to see some of our coolest overnight lows in two months.

Unfortunately this cool down will be brief as high pressure will be building once again and driving temperatures up for the balance of the week. Check out the extended forecast here for details.

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Caribbean girds for Hurricane Irma threat

Tuesday, September 5th, 2017 5:10am MST

Irma, a still strengthening and dangerous Category Four hurricane, churned toward the Leeward Islands early Tuesday, sparking alarm and alerts from the Caribbean to Florida, which declared an emergency. The National Hurricane Center said at 0300 GMT that the storm was packing top sustained winds of 140 mph (220 km/h). “Additional strengthening is forecast during the… » Click here to read the rest of Caribbean girds for Hurricane Irma threat

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August 2017 weather recap: Cooler than normal with near average precipitation

Tuesday, September 5th, 2017 5:06am MST

The last full summer month of the year has come to a close in a rather un-dramatic fashion.  Thornton saw a largely pleasant month with temperatures a good bit cooler than we usually expect to see. Precipitation was right near normal however, all of it fell during the first half of the month.

High pressure ruled for the first two days of the month but then the ridge broke down bringing about cooler temperatures on the 3rd of the month. The cool down didn’t last long and while the heat returned for a couple of days, we did finally receive some moisture on the 4th and 5th.

Cooler than normal temperatures returned on the 6th and lasted through the next 10 days.  The first half of the month also saw 10 days with measurable precipitation, our only precipitation for the month as the last half of the month saw none at all.

Dry and warm conditions were the rule of thumb for the last two weeks of the month.  Both Thornton and Denver saw six of the last nine days of the month bring high temperatures at or above 90 degrees.

Our average temperature for the month came in at 68.9 degrees.  This was a good bit below the long term Denver average for August of 72.5 degrees.  Out at DIA where the Mile High City’s official measurements are taken, the month was warmer than us but still cooler than normal with an average of 71.5 degrees.

Temperatures in Thornton ranged from a high mark reading of 94.9 degrees on the 29th of the month down to a low of 51.2 degrees on the 11th.  Denver saw a maximum reading of 95 degrees on the 19th of the month and a low of 51 degrees on the 4th.

In terms of precipitation, Denver averages 1.69 inches of precipitation during August.  Thornton wasn’t too far short of that with 1.43 inches.  However, all of that came during the first 15 days of the month. After that, we saw nothing.  Denver best us, and the average, with 1.86 inches in their rain bucket.

Click here to view Thornton’s August 2017 climate report.

Thornton, Colorado's August 2017 Temperature Summary. (ThorntonWeather.com)

Thornton, Colorado’s August 2017 Temperature Summary. (ThorntonWeather.com)

Thornton, Colorado's August 2017 Precipitation Summary. (ThorntonWeather.com)

Thornton, Colorado’s August 2017 Precipitation Summary. (ThorntonWeather.com)

639 PM MDT FRI SEP 1 2017




                 VALUE   DATE(S)  VALUE   FROM    VALUE  DATE(S)
 HIGH             105   08/08/1878
 LOW               40   08/26/1910
HIGHEST            95   08/19        96      -1       97  08/09
LOWEST             51   08/04        50       1       47  08/25
AVG. MAXIMUM     85.7              87.2    -1.5     86.3
AVG. MINIMUM     57.3              57.9    -0.6     56.2
MEAN             71.5              72.5    -1.0     71.2
DAYS MAX >= 90     10              11.5    -1.5       15
DAYS MAX <= 32      0               0.0     0.0        0
DAYS MIN <= 32      0               0.0     0.0        0
DAYS MIN <= 0       0               0.0     0.0        0

 MAXIMUM         5.85   1979
 MINIMUM         0.02   1924
TOTALS           1.86              1.69    0.17     0.22
DAILY AVG.       0.06              0.05    0.01     0.01
DAYS >= .01         6               8.6    -2.6        4
DAYS >= .10         4               4.3    -0.3        1
DAYS >= .50         2               1.2     0.8        0
DAYS >= 1.00        0               0.3    -0.3        0
 24 HR. TOTAL    0.90   08/07 TO 08/07           08/24 TO 08/24

TOTALS            0.0 2017          0.0

HEATING TOTAL       8                10      -2       15
 SINCE 7/1          8                16      -8       15
COOLING TOTAL     216               244     -28      218
 SINCE 1/1        749               688      61      762

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

AVERAGE WIND SPEED              9.2

AVERAGE SKY COVER           0.50
NUMBER OF DAYS FAIR            7
NUMBER OF DAYS PC             21


THUNDERSTORM             13     MIXED PRECIP               0
HEAVY RAIN                3     RAIN                       4
LIGHT RAIN               12     FREEZING RAIN              0
LT FREEZING RAIN          0     HAIL                       0
HEAVY SNOW                0     SNOW                       0
LIGHT SNOW                0     SLEET                      0
FOG                      10     FOG W/VIS <= 1/4 MILE      2
HAZE                      2

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September 3 to September 9: This week in Denver weather history

Tuesday, September 5th, 2017 3:23am MST
This Week In Denver Weather History

September 3 to September 9: This Week in Denver Weather History

The first full week of September sees us start one of the most pleasant times of year in Denver. While less common this time year, severe weather can and does occur. Our look back at this week in Denver weather history includes hail, damaging wind and even smoke from wildfires hundreds of miles away.

From the National Weather Service


In 1995…record breaking heat occurred on the first 5 days of the month when the temperature climbed into the 90’s on each day. Record high temperatures of 97 degrees on both the 1st and 4th equaled the all-time record maximum for the month. High temperature of 95 degrees on the 3rd was a record for the date. High temperatures of 94 degrees on both the 2nd and the 5th were not records. The low temperature of 64 degrees on the 4th equaled the record high minimum for the date.


In 1978…the temperature reached 90 degrees or more on seven consecutive days with the highest temperature…94 degrees… Recorded on both the 4th and 6th.


In 1892…there was a trace of rainfall each day. This… Together with a trace of rain on both the 7th and 8th…was the only rainfall of the month…making the month the driest on record. The monthly record was equaled in 1944.


In 1901…a thunderstorm produced rain…hail of unknown size… And south winds sustained to 40 mph with gusts to 43 mph.

In 1961…Labor Day snow storm is the earliest date of the first snow…trace and measurable…of the season. The heavy wet snow broke many limbs from trees that were still in full foliage. The storm produced 4.2 inches of snowfall at Stapleton Airport with nearly a foot of snow in western suburbs and in the foothills. Minimum temperature of 33 degrees was a record for the date and the coldest ever recorded so early in the season.

In 1999…severe thunderstorms dumped large hail across metro Denver. Hail as large as 1 inch in diameter was measured near Cherry Creek in Aurora and near Bennett. Hail to 3/4 inch in diameter fell in the city of Denver.

In 2002…a thunderstorm produced a wind gust to 51 mph at Denver International Airport.

In 2003…very heavy thunderstorm rain washed out parts of the Virginia Canyon Road above Idaho Springs. Up to 4 feet of mud reportedly washed down the road during the storm. Several vehicles were trapped on the road.

In Idaho Springs…several streets…including the main street… Were also buried in mud and gravel. Some buildings in town experienced minor flooding…including the basement of the town library and the police station.


In 1909…rainfall for the 4 days accumulated to 3.97 inches in Boulder…while in Denver rainfall totaled 2.45 inches on the 4th…5th…and 6th.


In 1909…apparent post-frontal heavy rainfall totaled 1.94 inches in downtown Denver. North winds were sustained to 19 mph.

In 1944…a trace of rain fell. This together with a trace of rain on the 9th…10th…and 30th was the only precipitation for the month. The total of a trace of precipitation for the month equaled the driest September on record first set in 1892.

In 1960…the highest recorded temperature in September…97 degrees…occurred. The same temperature also occurred on September 5…1899…September 1…1995…and September 4… 1995.

In 1989…a strong thunderstorm wind gust flipped a plane taxiing on a private runway in Adams County east of Denver. Two people were slightly injured and the plane was heavily damaged.

In 1992…strong winds developed across metro Denver behind a pacific cold front. Sustained winds above 40 mph with gusts as high as 60 mph were recorded mainly in and near the foothills. Pre-frontal south winds gusted to 37 mph at Stapleton International Airport.

In 1995…two people were injured when lightning struck their home in Lakewood. The lightning entered the attic where it started a small fire. It then traveled through the walls… Exploding a mirror and spraying glass on the residents. Lightning also sparked small grass fires near Aurora…Denver International Airport…and Bennett. The highest recorded temperature in September…97 degrees…occurred. The same temperature also occurred on September 5…1899…September 4…1960…and September 1…1995.

In 2000…thunderstorm winds gusted to 64 mph in Castle Rock.


In 1899…the highest recorded temperature in September…97 degrees…occurred. The same temperature was also reached on September 4…1960…and September 1 and 4…1995.

In 1940…a severe wind and hail storm confined mostly to the west and north parts of the city occurred shortly after 4:30 pm. Hail stones ranged in size from 1/4 to 1/2 inch in diameter. In north Denver…hail piled to a depth of 4 inches. Flooding occurred in one underpass…which stalled 2 cars. One girl was injured when the weight of the hail flattened a porch on which she stood. Northeast winds were sustained to 29 mph with gusts to 32 mph in downtown Denver.

In 1987…a thunderstorm complex produced hail as large as 1 3/8 inches in diameter…2 miles east of Buckley Field in Aurora. No damage was reported.

» Click here to read the rest of September 3 to September 9: This week in Denver weather history

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Denver sets a new record high temperature for September 3

Sunday, September 3rd, 2017 5:27pm MST

Record High TemperaturesWhew! Is this September or July?  As expected the mercury kept on climbing today and did indeed get into record-setting territory.

At 1:53pm the temperature at Denver International Airport where the Mile High City’s official records are kept reached 97 degrees.  This easily bests the previous record high for the date of 95 degrees set in 1995.

Additionally the reading tied the record for hottest September temperature.  Six other times in the past the mercury reached 97 degrees during September occurring on September 1, 1995, September 4, 1960, September 4, 1995, September 5, 1899, September 5, 2013, and September 6, 2013.

Here in Thornton, we were actually warmer than DIA (a rarity).  Temperatures here topped out at 98.5 degrees at 1:20pm.

While above normal temperatures (but not record-setting) are expected for tomorrow, we do expect to see a significant cool down Tuesday then see things bounce back to readings a bit above normal for the balance of the week. See the extended forecast here.

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Labor Day weekend to bring dry, very warm conditions to Thornton

Friday, September 1st, 2017 5:05am MST

While we start out the four-day period a little bit unsettled on Friday, things will dry out and warm up for the rest of the long weekend.

For today a weak trough mixes things up a bit with a few sprinkles of rain in the morning and a slight chance for a thunderstorm in the first half of the afternoon. Highs today will top out in the mid to upper 80s under partly sunny skies. Tonight the skies will clear and we will see lows in the upper 50s.

Saturday will be a very nice, albeit warm, day. Looks for lots of sun, dry and calm conditions with highs in the low 90s. Overnight Saturday into Sunday morning skies will be mostly clear and lows near 60 degrees.

The heat is on for Sunday. Highs will be in the mid-90s with plenty of sun and dry conditions. Sunday night into Monday morning lows will again be near 60 degrees.

Labor Day brings the unofficial end to summer with a nice day but with a few more clouds. We do expect to remain dry though and highs will be right around the 90 degree mark.

Have a fun, safe holiday weekend!

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