Thornton, Colorado, USA
UpdatedTue, 30-Sep-2014 9:55pm MDT 


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Thornton’s October weather preview: Fall begins to make its presence felt

Tuesday, September 30th, 2014 5:30am 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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Tuesday brings drier conditions but also breezy winds

Tuesday, September 30th, 2014 5:14am MDT

Following Monday’s healthy shot of rain, today will be dry in Thornton and with near normal temperatures and a touch of wind.  We’ll see wet conditions return Wednesday then dry up and warm up through the weekend.

We’re starting the early morning today in the mid-40s and will be warming to a high in the upper 60s.  Mostly sunny skies will be above today with a few more clouds appearing starting mid-morning into the early afternoon.  Look for breezy winds at 10mph, gusting to 20mph or so for the better part of the day.

Looking ahead, Wednesday looks to be another wet one and while there will be rain, it doesn’t look like it will have the thunderstorm drama we saw yesterday.  For Thursday and going forward, dry conditions return and temperatures will start warming up.

Keep an eye on the mercury and winds here.

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September 28 to October 4: This Week in Denver Weather History

Tuesday, September 30th, 2014 5:06am MDT
This Week In Denver Weather History

September 28 to October 4: This Week in Denver Weather History

Late September and early October are usually relatively calm in Denver however that isn’t always the case. In our look back at his week in weather history, we see that heavy, wet snow can arrive causing extensive damage – and even death. Severe thunderstorms have also occurred bringing large hail and even torndoes.

From the National Weather Service:


In 1936…the heaviest snowfall ever recorded in September and the heaviest snowfall ever recorded so early in the season dumped a total of 16.5 inches of snow on downtown Denver and 21.3 inches at Denver municipal airport. The 15.0 inches of snow measured from 6:00 pm on the 27th to 6:00 pm on the 28th is the greatest 24 hour snowfall ever recorded in September. This was the first snow of the season. The snow was intermittent through the 26th…but continuous from early afternoon on the 27th to around midnight on the 28th…except for a period of rain during the afternoon of the 28th which contributed to a loss of depth on the ground. The greatest snow depth on the ground downtown was 13 inches with 8 inches at Denver municipal airport. There were no high winds with the storm and traffic was interrupted for only a short period. The storm produced property damage estimated at 7 million dollars. With trees and shrubs in full foliage…the leaves caught and held the heavy water-laden snow…until the branches snapped from the weight. More than 3000 workmen were called to remove the debris and snow from the city. The city firemen who were off duty…as well as all the reserves… Were asked to report to their stations. All schools in the city remained open…but attendance was only 50 percent of normal. Grade school students were sent home at noon on the 28th. The early storm caught stockmen with many cattle still in higher ranges. Warm weather followed the snow…which had all melted by the end of the month…except for a few inches in sheltered places.


In 1984…heavy snow fell over the plains and foothills. Snowfall amounts ranged from 2 to 5 inches on the plains with up to a foot at higher elevations in the foothills. The main problem caused by the storm was thousands of power outages caused by snow-laden tree limbs snapping and falling onto power lines. Over 15 thousand homes lost power in metro Denver. Some cars were damaged by falling trees and limbs. The snow also caused some flight delays at Stapleton International Airport where 5.1 inches of snow fell and northeast winds gusted to 29 mph. Maximum snow depth on the ground was 3 inches due to melting. The high temperature of only 34 degrees on the 28th was a record low maximum for the date and equaled the all-time record for the month at that time.


In 1877…heavy dense smoke from mountain forest fires spread over the city. The smoke was so dense that it obscured the sun at times.

In 1921…post-frontal northeast winds were sustained to 44 mph.

In 1953…a pacific cold front produced a west wind gust to 59 mph at Stapleton Airport where the visibility was briefly reduced to 3/4 miles in blowing dust. Strong winds were also widespread over Boulder during the afternoon.

In 1960…strong…gusty winds tore the roof from 6 units of a motel on West Colfax Avenue in Denver. The roofing sailed over the building and crashed down on a truck…wrecking it. The strong winds were the result of an apparent microburst.

In 1999…snow fell in the foothills west of metro Denver and over the plains. Snowfall totals included 7 inches at Conifer. At the site of the former Stapleton International Airport…3.1 inches of snow were measured. This was the first snow of the season. The heavy wet snow snapped branches from fully leafed trees…downing power lines and causing scattered outages.

In 2004…severe thunderstorms produced hail to 3/4 inch in diameter in Littleton and in Douglas County 14 miles northwest of Castle Rock.

In 2012…a weak tornado (ef-0) tornado touched down near Strasburg. No damage was reported.


In 1959…one of the heaviest September snow storms of record began as rain and changed to heavy wet snow. The storm caused heavy damage to trees and shrubbery…which were still in full leaf. The storm dumped 10.6 inches of snow at Stapleton Airport…the third heaviest September snow amount to date. Falling trees and limbs disrupted traffic…broke power and communication lines…and damaged buildings and cars. One man was killed in Denver by a falling tree limb…and four others died of heart attacks while shoveling snow or trying to move heavy tree limbs. Direct costs of the storm for cleaning up debris…repairing utility lines…and damage to buildings and other property across all of eastern Colorado were estimated to be over a half million dollars. The value of trees destroyed or damaged was estimated to exceed five million dollars. North-northeast winds gusted to 32 mph at Stapleton Airport on the 28th.

In 1985…an unusually cold air mass for this time of year settled over the area. Metro Denver received 8 to 12 inches of powdery snow. The 8.7 inches of snow that fell at Stapleton International Airport was the first measurable snow of the season and the city’s heaviest September snowfall since 1971. The snow caused flight delays of over 2 hours at Stapleton International Airport. I-70 was closed for a time west of Denver. Snow-laden tree limbs snapped over all of metro Denver…causing widespread power outages. Ten thousand people were without electricity for a time in Boulder. The morning of the 29th saw mid-winter temperatures along the Front Range. The temperature dipped to 17 degrees…the lowest temperature ever recorded in September in Denver. The high temperature of only 29 degrees on the 29th was a new record low maximum for the date and lowest ever recorded during the month of September. The low temperature of 21 degrees on the evening of the 28th set a new record low for the date. The cold weather persisted through the 1st with record minimum temperatures of 25 degrees set on the 30th and 27 degrees set on October 1st.


In 1966…a vigorous cold front moved thru metro Denver. North winds gusting to 51 mph kicked up billows of blowing dust…which briefly reduced the visibility to 1 mile at Stapleton International Airport. The cold air caused temperatures to drop rapidly from a high of 86 degrees to a low of 46 degrees by days end.

In 1985…the lowest temperature ever recorded in September… 17 degrees…occurred. The high temperature warmed to only 29 degrees…the all-time record low maximum for the month.

In 1994…the temperature reached a high of 91 degrees at Stapleton International Airport. This was the 60th day of the year that the temperature had reached 90 degrees or more…establishing a new record at that time. The previous record of 52 “90 degree days” occurred in 1978. Only 43 “90 degree days” were recorded at Denver International Airport during 1994.

In 1995…lightning struck a couple in Aurora as they were walking in the rain. The bolt struck the umbrella the man was carrying…injuring both the man and his wife.

In 2000…late afternoon thunderstorms produced strong wind gusts to 76 mph in Westminster…to 69 mph near Boulder…and to 60 mph at Jefferson County Airport near Broomfield. No damage was reported.


In 1898…south winds were sustained to 41 mph with gusts to 54 mph.

In 1940…a late season thunderstorm in the city caused one lightning death.

In 1944…the month ended with a trace of rain on this date and for the month. A trace of rain also occurred on the 4th…9th…and 10th. There was no measurable 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 2009…a trained spotter in Coal Creek Canyon…recorded a peak wind gust to 88 mph.

» Click here to read the rest of September 28 to October 4: This Week in Denver Weather History

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September 2014 top shots: Monthly photo slideshow

Tuesday, September 30th, 2014 5:05am MDT
September 3, 2014 - A pastel colored sunset in Thornton. (Michelle Jones)

September 3, 2014 – A pastel colored sunset in Thornton. (Michelle Jones)

The month of September is typically one of the more pleasant months in Colorado.  Temperatures are usually comfortable and there is not normally a lot of weather drama.  That however does not mean there aren’t plenty of photo opportunities.

Wildlife is still quite active along the Front Range and flowers will hold on to their petals for at least the first part of the month.  Then of course there is the weather which you never know what to expect.  Thunderstorms, heavy rain, and even snow are a possibility.

  • Slideshow updated September 30, 2014
  • To learn more about how to send your photo to us for inclusion in the slideshow, see below the slideshow.

Showcasing images captured by ThorntonWeather.com readers as well as some of our own, our monthly slideshow covers the entire gamut of weather-related imagery.

Sunsets, sunrises, wildlife and of course every type of weather condition are vividly depicted in images captured from yours and our cameras.

Click the play button below and sit back and enjoy the images.

What is missing in the slideshow above?  Your photo!

Our monthly photo slideshow is going to feature images that we have taken but more importantly images that you have captured.  The photos can be of anything even remotely weather-related.

Landscapes, current conditions, wildlife, pets, kids.  Whimsical, newsy, artsy.  Taken at the zoo, some other area attraction, a local park, a national park or your backyard.  You name it, we want to see and share it!

Images can be taken in Thornton, Denver or anywhere across the extraordinary Centennial State.  We’ll even take some from out of state if we can tie it to Colorado somehow.

We’ll keep the criteria very open to interpretation with just about any image eligible to be shown in our slideshows.

What do you win for having your image in our slideshow?  We are just a ‘mom and pop’ outfit and make no money from our site so we really don’t have the means to provide prizes.  However you will have our undying gratitude and the satisfaction that your images are shared on the most popular website in Thornton.

To share you images with us and get them included in the slideshow just email them to us or share them with ThorntonWeather.com on any of the various social media outlets.  Links are provided below.

So come on, get those camera’s rolling!

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A cool, active day of weather starts Thornton’s workweek

Monday, September 29th, 2014 5:57am MDT

A strong storm system will be moving into the area today leading to a good chance for thunderstorms, some with the potential to turn severe.

We start out today with partly sunny skies.  Cloud cover will be increasing as the day progresses.  Temperatures will be topping out near 70 degrees, a bit shy of the average for the date of 73 degrees.

A few sprinkles will be possible during the morning hours.  As the day warms up, so too does the chance for storm activity.  There will be a chance for thunderstorms after 2:00pm and then they become likely after 4:00pm.

The strongest of these are expected to be east and northeast of us however we can’t rule out some severe activity in the metro area.  Some of these storms could bring brief, heavy rain, strong winds, large hail and even a tornado or two.

See the image for your Monday weather planner and keep an eye on our Severe Weather Briefing Page as the day progresses.

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Thornton to enjoy a very mild, pleasant Friday and weekend

Friday, September 26th, 2014 6:57am MDT

If you’re ready for fall-like weather you are going to have wait a couple more days as unseasonably warm weather will be lingering.  Starting Sunday however we do expect to see a turn toward cooler conditions.

For Friday we close out the workweek with a day much like the last couple.  Temperatures will be climbing to the mid to upper 80s with sunny skies above.

Saturday will be much like today but with highs a few degrees cooler but still well above average.

Temperatures close to 80 degrees and some late day thunderstorms will be the weather features Sunday.

The trough that will be digging in Sunday will usher in cooler weather through next week.  The image has your weekend weather outlook and of course http://www.thorntonweather.com your place to go for the latest.

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September 21 to September 27: This Week in Denver Weather History

Friday, September 26th, 2014 6:00am MDT
This Week In Denver Weather History

September 21 to September 27: This Week in Denver Weather History

Our look back at this week in Denver weather history is somewhat shorter than normal owing to the fact that this time of year is usually relatively quiet. However, what is notable are some significant snowstorms, including one as recently as 1995.

From the National Weather Service:


In 1963…heavy rain and hail caused local flooding in southeast Denver. Thunderstorm rainfall was only 0.60 inch at Stapleton Airport on the 20th.

In 1983…the cold front on the 19th brought an unusually cold air mass into metro Denver for so early in the season. The temperature dipped to a daily record minimum of 28 degrees on both days.

In 1995…a vigorous late summer storm brought the season’s first heavy snow to portions of metro Denver. Millions of trees were damaged and power lines downed as 4 to 8 inches of heavy wet snow settled on fully leafed trees in the Boulder and Denver areas. Branches snapped and trees split under the weight of heavy snow…downing power lines. Firefighters responded to numerous transformer fires. Around 100 thousand people were left without electricity in Boulder and Denver areas alone. It took over a week to fully restore power to some areas. Insurance claims were estimated to be around 6 million dollars to homes in metro Denver and about 500 thousand dollars in damage to automobiles. It was estimated that about 80 percent of 125 million dollars’ worth of city owned trees in Denver were damaged. Snowfall totaled 7.4 inches at the site of the former Stapleton International Airport where the greatest depth of snow on the ground was only 4 inches due to melting. Temperature records were set on the 21st when the thermometer dipped to a record low reading of 27 degrees and climbed to a high of only 36 degrees… Setting a record low maximum for the date. North winds gusted to 29 mph at Denver International Airport on the 20th.


In 1902…a thunderstorm on the 20th…in advance of an apparent cold front…produced rain…hail…and northwest winds to 40 mph with gusts to 48 mph. Widespread rain developed behind the cold front and totaled 3.21 inches from the evening of the 20th through the early afternoon of the 22nd. The 2.70 inches of precipitation recorded from 800 pm on the 20th to 800 pm on the 21st is the greatest 24 hour precipitation ever recorded in the month of September. The temperature dipped from a high of 80 degrees on the 20th to a high of only 51 degrees on the 21st.


In 1951…4.2 inches of snow fell at Stapleton Airport… Where northeast winds gusted to 27 mph. This was the first snowfall of the season in Denver…marking the end of the second shortest snow-free period on record…109 days…from June 4th through September 20th. A trace of snow fell on June 3rd.

In 1984…thunderstorm winds gusted to 56 mph at Stapleton Airport.

In 1992…the only precipitation of the month at Stapleton International Airport…0.01 inch of rain…fell from a brief shower around daybreak.

In 2009…an early season storm brought moderate to heavy snow to the foothills of Clear Creek…Jefferson and Park counties…west and southwest of Denver. A trained spotter…4 miles west-northwest of Conifer…was the big winner with 14 inches of snow. Storm totals elsewhere generally ranged from 5 to 10 inches.


In 1870…strong winds occurred in the foothills and in Boulder and Denver.

In 1895…rain changed to snow overnight and totaled 11.4 inches in downtown Denver. This was the first snowfall of the season and the second heaviest first snowfall of the season on record. North winds were sustained to 27 mph with gusts to 30 mph on the 21st.


In 1913…a thunderstorm produced northwest winds sustained to 40 mph with gusts to 44 mph.

In 1946…a trace of snow fell in downtown Denver. This marked the start of the longest snow season on record… 263 days through June 11…1947…when a trace of snow also fell.


In 1873…north to northwest winds blowing almost a gale spread clouds of dust and sand into the city during the afternoon and evening. From the roof of the weather observer’s building…houses a few hundred yards away were not visible and not even the sky could be seen through the clouds of sand. The wind reached sustained speeds of 35 mph…but only 28 mph was registered for any one hour.

In 1977…wind gusts from 50 to 80 mph were reported along the foothills. A northwest wind gust to 53 mph was recorded at Stapleton International Airport.


In 2000…the first snowstorm of the season brought heavy snow to areas in and near the foothills. While the heaviest snow fell north of metro Denver…6 inches were measured in Boulder…4 inches at both Castle Rock and Morrison…but only 0.2 inch at the site of the former Stapleton International Airport where most of the precipitation fell as rain. At Denver International Airport where drizzle and rain fell on the 23rd… Snowfall during the early morning of the 24th was estimated at 2.1 inches due to melting. The foothills west of Denver received more snow with 10 inches measured at Conifer…9 inches 11 miles southwest of Morrison… 8 inches atop Crow Hill…7 inches at Chief Hosa…and 5 inches at Ralston Reservoir.


In 1901…northwest winds were sustained to 50 mph with gusts as high as 57 mph in the city.

In 1932…thunderstorm rainfall of only 0.11 inch was the only measurable precipitation for the month that year in the city.

In 1986…a very strong wind storm roared across metro Denver. Boulder was hit hardest. Winds peaked to 131 mph at the National Center for Atmospheric Research. This is thought to be the highest wind gust ever recorded in Boulder during September. A wind gust to 118 mph was clocked on Davidson Mesa and to 92 mph near Niwot. Gusts of 70 to 80 mph were common over all of Boulder where an estimated 70 to 90 large trees were uprooted. About a dozen of them hit cars. Two walls of a building under construction were toppled and solar panels were blown off a house. Traffic lights and power lines were downed. Damage to power equipment alone was estimated at 100 thousand dollars. Wind gusts to 87 mph at Jefferson County Airport damaged two planes. A woman was seriously injured in Boulder. She suffered a fractured skull when struck by a falling tree limb. Trees were also downed in Louisville and Lafayette. West wind gusts to 45 mph were recorded at Stapleton International Airport.


In 1873…a fire was sighted in the woods near Platte Canyon… Probably caused by high winds blowing sparks among the timber.

In 1896…an apparent cold front produced northeast sustained winds to 40 mph with gusts to 48 mph.

In 1910…a thunderstorm produced sustained north winds to 51 mph. This was the highest recorded wind speed in the city in September at the time.

In 1936…a vigorous cold front produced a deadly dust storm in the city. North winds sustained to 36 mph with gusts to 38 mph produced much blowing dense dust…greatly restricting the visibility. The temperature plunged from a high of 84 degrees to a low of 38 degrees by midnight. The weather observer described the event with the following. “at 6:00 pm the temperature was 82 degrees and the wind velocity was only 4 mph; but with the wind shifting to the north and the barometer rising quite rapidly…the temperature fell sharply. By 6:30 pm…the wind velocity increased rapidly and by 7:00 pm had reached a maximum sustained velocity of 36 mph…bringing with it clouds of dust which had been picked up by gale force winds in southern Wyoming and northern Colorado…covering the city. The visibility was generally reduced to about 1/4 mile; however…the whirling of the dust down the streets and alleys…the visibility was at times somewhat less. Airplanes were grounded…traffic was halted at times…and homes filled with dust. The strong winds damaged electric power and telephone lines…leaving homes in darkness for a few hours in the city and for 18 hours in suburban towns and putting 2500 telephones out of service because of broken lines. An electric lineman was killed while repairing damage by the high winds. The dust storm was followed by rain that began falling at 10:55 pm…which turned to snow during the early morning hours of the 26th. A major snow storm followed on the 27th through the 29th.”

In 1999…high winds developed in the foothills of Boulder County. Winds gusted to 90 mph at Wondervu.

» Click here to read the rest of September 21 to September 27: This Week in Denver Weather History

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Video: Toddlers debate sprinkles versus rain

Thursday, September 25th, 2014 1:04pm MDT
Sprinkles vs rain: Toddlers debate the weighty issue. (YouTube / Tara Willmott)

Sprinkles vs rain: Toddlers debate the weighty issue. (YouTube / Tara Willmott)

Certainly politics, religion and even climate change are hotly debated topics but as a video shows, toddlers can get pretty fired up about whether it is sprinkling or raining.

Posted to YouTube yesterday, the video portrays how quickly a discussion about the weather can get heated.

A young boy insists it is just sprinkling – because his mom told him it was – while two twin girls demand it is raining.

Strong words are exchanged and soon some poking ensues.  The boy learns a harsh lesson about disagreeing with girls as one ‘pokes his heart’ and brings him to tears.

Like many debates likely conducted by these toddlers’ parents, in the end everyone insists they are right and no minds seem to be changed.  ;-)

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Lots of sun, very mild temperatures for Thornton’s Thursday

Thursday, September 25th, 2014 5:40am MDT

The weather today is going to look quite like yesterday with the only real difference being temperatures climbing even further.  We then see a couple more unseasonably warm days before we cool down to temps closer to normal.

For today we start out the day with sunny skies and then a few clouds by mid to late morning.  All that sun coupled with high pressure is going to allow the mercury to rise to the upper 80s by mid-afternoon or so.

Friday and Saturday will also be unseasonably warm before a trough moves through later in the day Saturday.  Once it does, we should see cooler temperatures at or below average for the period from Sunday through at least the middle of next week.

The image has your outlook for today and you can keep an eye on the thermometer here: http://www.thorntonweather.com/live-weather-2.php #Colorado #Weather

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A near perfect early fall day in Thornton

Wednesday, September 24th, 2014 6:06am MDT

If sun, dry conditions and unseasonably warm temperatures are your preference then you are going to enjoy Wednesday’s weather.  In fact, similar weather can be expected through the end of the workweek.

For today look for sunny skies to kick things off.  A few clouds will move in this afternoon but it will remain mostly sunny.  No storms are expected in our area or really anywhere in northeastern Colorado for that matter.  Temperatures today in Thornton will be topping out around 83 degrees, a good ways above the average for the date of 75 degrees.

Thursday and Friday look to be similarly dry and sunny with even warmer temperatures hitting the mid to upper 80s.

All the latest here: http://www.thorntonweather.com/

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