Thornton, Colorado, USA
UpdatedWed, 16-Jan-2019 9:45pm MST 


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Wednesday to offer warm temperatures, just a slight chance for storms

Wednesday, August 8th, 2018 5:02am MST

A fine looking summer day ahead for Thornton. Temperatures will be close to normal and the afternoon and evening offer only a bit of a chance for storms.

We start out under clear skies and will enjoy lots of sun for much of the day. The mid-afternoon will bring a few clouds but nothing too intrusive. Highs today will top in the upper 80s, close to the average high of 89 degrees.

Thunderstorm activity should be quite isolated today with activity largely to our west and south. We may see something pop up after 4:00pm but chances don’t appear good.

Tonight, lows will dip to around the 60 degree mark.

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Comfortable temperatures, slight chance for storms for Thornton’s Tuesday

Tuesday, August 7th, 2018 5:00am MST

A pretty nice looking day ahead for us. Temperatures will be below normal and quite pleasant while the evening offers up a typical chance for thunderstorms.

We start out the day under sunny skies then will see a few clouds later this morning with a further increase in coverage in the afternoon. Temperatures will top out in the mid-80s, a bit below normal, making for a nice one.

Late afternoon brings a slight chance for thunderstorms with the best opportunity coming after 6:00pm. Right now it appears most activity will be to our south but we can’t rule out some isolated storms our way.

Tonight, any storms will settle down after dark and we will be left with clearing skies and lows in the upper 50s.

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Thornton’s August 2018 preview: Temperatures moderate, severe weather decreases

Monday, August 6th, 2018 6:46pm MST

As summer vacations wind down and families prepare to send their kids back to school in August, Colorado weather also starts to settle down. The chances for severe weather decrease markedly during August and by the end of the month daytime temperatures are dropping quite a bit as well.

Find out more about what lies ahead with Thornton’s August weather here.

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July 2018 weather recap: After a hot start, month cools down, gets wet

Monday, August 6th, 2018 7:40am MST

The month of July was somewhat a tale of two months in one.  The first half was most notable for their unseasonably warm temperatures and relatively dry conditions.  The second half saw a few days of heat but for the most part was considerably cooler and wetter.

Thornton saw an average temperature for the month of 73.5 degrees.  Out at Denver International Airport where the Mile High City’s official readings are taken, the month saw an average of 75.3 degrees.  Long term, the month of July sees an average of 74.2 degrees in Denver so while Thornton was cooler than that, Denver was warmer.

Thornton had its highest temperature reading of 99.9 degrees on the 19th and its coldest of 47.7 degrees on the 1st.  Denver saw its warmest reading of 99 degrees on the 3rd and its coldest of 47 degrees on the 1st.

In terms of precipitation, Denver’s long term July average is 2.16 inches.  Thornton easily bested that number with 3.66 inches in our rain bucket.  The Mile High City fell well short with only 1.03 inches.

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

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

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

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

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

305 PM MDT WED AUG 1 2018




                 VALUE   DATE(S)  VALUE   FROM    VALUE  DATE(S)
 HIGH             105   07/20/2005
 LOW               42   07/04/1903
HIGHEST            99   07/03        99       0      100  07/19
LOWEST             47   07/01        51      -4       51  07/01
AVG. MAXIMUM     90.2              89.4     0.8     91.5
AVG. MINIMUM     60.3              58.9     1.4     61.3
MEAN             75.3              74.2     1.1     76.4
DAYS MAX >= 90     19              16.0     3.0       20
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         6.41   1965
 MINIMUM         0.01   1901
TOTALS           1.03              2.16   -1.13     0.47
DAILY AVG.       0.03              0.07   -0.04     0.02
DAYS >= .01         8               8.3    -0.3        6
DAYS >= .10         3               4.3    -1.3        3
DAYS >= .50         0               1.4    -1.4        0
DAYS >= 1.00        0               0.7    -0.7        0
 24 HR. TOTAL    0.43   07/23 TO 07/23

 TOTAL            0.0               0.0
 TOTAL            0.0

HEATING TOTAL       0                 6      -6        0
 SINCE 7/1          0                 6      -6        0
COOLING TOTAL     326               289      37      360
 SINCE 1/1        615               444     171      533

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

AVERAGE WIND SPEED              10.1

AVERAGE SKY COVER           0.50
NUMBER OF DAYS FAIR           10
NUMBER OF DAYS PC             20


THUNDERSTORMS            13   MIXED PRECIP           0
HEAVY RAIN                3   RAIN                   5
LIGHT RAIN               11   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                       8   HAZE                   5

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Thornton’s workweek starts out with cooler temps, unsettled conditions

Monday, August 6th, 2018 4:56am MST

A nice break from the heat in store for us today. However, we do see the potential for thunderstorms, some potentially severe.

The day starts out with a bit of cloud cover but that will ease this morning through the early afternoon. Then, expect to see clouds increase as thunderstorms begin to build in the foothills and move across the area.

Best chance for storms will come after 3:00pm and then increase from there into the evening. Some of these storms could bring brief, heavy rain, gusty winds and perhaps some sizeable hail so please be aware.

High temperatures today will top out around a very comfortable 77 degrees.

Tonight, thunderstorm activity should be done by midnight then we will see gradually clearing skies. Overnight lows will be in the upper 50s.

Looking ahead, we have a pretty decent week ahead with highs in the mid-80s expected through Saturday.

In the meantime, keep an eye on the skies for those thunderstorms here.

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August 5 to August 11: This week in Denver weather history

Sunday, August 5th, 2018 6:34pm MST
This week in Denver weather history

August 5 to August 11: This week in Denver weather history

As we enter August the weather typical is a bit calmer as the atmosphere settles down. However our look back at this week in Denver weather history shows that Mother Nature can still visit plenty of excitement on us.

From the National Weather Service:


In 1881…the low temperature cooled to only 76 degrees…the record high minimum temperature for the month.

In 1889…southwest winds were sustained to 42 mph.

In 1918…hail pelted the city…but was light and caused no damage. Precipitation totaled 0.25 inch. Northwest winds were sustained to 31 mph.

In 1964…lightning struck two boys in Denver while playing ball. One was treated and released from the hospital…but the other boy suffered second degree electrical shock and cardiac arrest and was hospitalized in critical condition for several days.

In 1969…two tornadoes touched down briefly in an open field southeast of Buckley Field in Aurora. No damage was reported.

In 1970…heavy rain in the Indian Hills area in the foothills west of Denver caused flash flooding…which washed out roads and damaged other property. Hail accumulated to a 3 inch depth with stones up to golf ball size; however…most of the damage was from flooding.

In 1982…2.38 inches of rain fell in an hour in Arvada… Causing minor flooding on Ralston Creek. In Westminster… 1 1/2 inches of rain fell…causing damage to streets and culverts. In addition…lightning caused some minor power outages across metro Denver.

In 1983…very heavy thunderstorms hit the southern portion of metro Denver. Heavy rainfall…as much as 2.89 inches in 38 minutes…caused widespread street flooding in southeast Denver. Two feet of water covered a section of I-25. Hail up to golf ball size accompanied the storm in Littleton and Englewood…along with 60 mph winds.

In 1984…a heavy thunderstorm drenched Littleton with up to 2.35 inches of rain in an hour…along with small hail that piled up to 2 inches deep. Flood waters were up to 4 feet deep in parts of town with many basements flooded. There were some power outages caused by lightning.

In 1990…a thunderstorm dumped 1.25 inches of rain in 12 minutes near tower and smoky hill roads in southeast Aurora. Minor street flooding was reported in the area.

In 1992…a pilot reported two funnel clouds near Cheery Creek Reservoir. Both dissipated quickly. Dime size hail fell near Franktown.

In 1994…one inch diameter hail fell near Strasburg. No damage was reported.

In 1999…a dog kennel east of Denver International Airport… Was flooded when a small dam…upstream in Elbert County… Was breached. The floodwaters…up to 4 feet deep…washed away some 6-foot fences and other small buildings. Ten of the 70 dogs boarded at the kennel drowned.

In 2002…a mail carrier was struck by lightning as he inserted a key into a multi-unit mailbox in Bailey. The shock knocked the man back against the mail truck. He suffered minor injuries. Lightning struck a residence in Commerce City. The resulting fire destroyed the roof of a detached garage and damaged much of its contents. Hail as large as 1 3/4 inches in diameter pelted pine. One inch diameter hail fell in Arvada and southwest Denver. Heavy rain triggered a mudslide along U.S. Highway 285 near Bailey. Both lanes of traffic had to be closed until debris could be removed from the highway. Several residences in the Bailey and Glenisle areas were also flooded.

In 2004…heavy thunderstorm rainfall caused localized flash flooding in Virginia canyon near Idaho Springs. Sections of the Virginia Canyon Road had to be closed due to the floodwaters.

In 2008…a severe thunderstorm produced large hail…up to 1 1/4 inches in diameter…northeast of Parker. Several automobiles were damaged.


In 1877…a severe rain…hail…and wind storm struck Denver. The storm produced a one minute sustained wind speed of 75 mph. Rainfall totaled 1.00 inch in 25 minutes. The hail storm damaged vegetable gardens in the city.

In 1954…an unconfirmed tornado was reported in Westminster. A funnel cloud was sighted in the area…but it was not certain if it had touched down. No damage was reported.

In 1980…the temperature reached 100 degrees…setting a new record high for the date.

In 1982…3/4 inch diameter hail was reported in north Denver. Heavy rain caused street flooding in central Denver where 4 to 5 feet of water inundated I-25…closing the freeway for a while. Rainfall across metro Denver ranged up to 2.35 inches in just over an hour. An estimated 2000 basements were flooded. Only 0.01 inch of rain fell at Stapleton International Airport.

In 1991…heavy rain caused flooding at the junction of I-25 and I-70. Dime size hail was reported northeast of Boulder near Niwot.

In 1995…microburst winds gusting as high as 58 mph caused minor damage to an apartment complex in Broomfield. Some homes under construction were also damaged when the winds knocked over 2 by 4 wood beams along with some insulation and roofing materials…which broke a few windows. Microburst winds also overturned a camper near Barr Lake.

In 1996…hail ranging in size from 1 to 1 1/2 inches fell near Bennett.

In 2001…3/4 inch hail fell in the foothills near conifer.

In 2008…a record daily rainfall record was set at Denver International Airport. The record of 1.29 inches in 24 hours broke the previous record of 1.10 inches set in 1929.


In 1948…a brief west moving tornado was sighted 3 miles north-northeast of Stapleton Airport. The white funnel silhouetted against a gray cloud background was very narrow…nearly vertical…and estimated at nearly 5 thousand feet high. A dust cloud formed on the ground around the funnel. No damage was reported.

In 1952…a thunderstorm wind gust to 52 mph was recorded at Stapleton Airport.

In 2014…severe thunderstorms produced large hail across western and southern parts of metro Denver. Near Centennial and Golden…hail up to quarter size was reported. Near Bennett…a peak thunderstorm wind gust to 65 mph was also reported. At Denver International Airport…a peak wind gust to 46 mph was recorded.


In 1874…swarms of grasshoppers invaded the city. Millions of them were seen cruising through the air. The insects were apparently picked up by a thunderstorm gust front and carried into the city. The grasshoppers had ravaged crops in surrounding counties for the last month.

In 1878…the highest temperature ever recorded in Denver…105 degrees…occurred at 3:20 pm. This temperature was equaled on July 20th in 2005.

In 1969…the temperature reached 100 degrees at Stapleton International Airport.

In 1976…in Thornton…a 13 year old boy riding a bicycle was struck and killed by lightning.

In 2000…lightning struck three homes in central Arapahoe County east of Denver. Damage was estimated at 47 thousand dollars.

In 2003…hail to 1 inch in diameter pelted Denver. Hail to 7/8 inch was measured in Boulder.

In 2008…heavy rain also caused flash flooding over south Denver and its nearby suburbs. Heavy rain…from 2.5 to 4 inches…fell in less than 90 minutes. Firefighters rescued 20 people as the water quickly rose along creeks…flooded roadways…and stranded motorists. Three people had to be rescued along Cherry Creek when the bike path flooded.

In Evergreen…a man suffered minor injuries when he was struck by lightning. It entered his finger…traveled down his body… And exited his foot.

In 2013…heavy rain caused localized flash flooding in Aurora. An undergound parking garage at an apartment complex was inundated with 3 to 4 feet of water. Flash flooding forced a road closure at East Mississippi Ave. and Alton St. Also… several people had to be rescued when three vehicles stalled in floodwaters at Alameda Ave. and Havana St. The stationary thunderstorms dumped 2.75 inches of rain in less than 45 minutes. In addition…large hail…up to one inch in diameter…was reported north of Roxbourough State Park. At Denver International Airport…just a trace of rainfall was observed.

» Click here to read the rest of August 5 to August 11: This week in Denver weather history

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July 2018 top shots: Monthly photo slideshow

Tuesday, July 31st, 2018 4:23pm MST
Smoke from area wildfires helps color the sky orange at sunrise. (Jessica Fey)

Smoke from area wildfires helps color the sky orange at sunrise. (Jessica Fey)

Colorado offers outdoor opportunities unlike any other state and while the summer heat settles in, photos of the amazing scenes across our state provide a view into why we love it here so much.

The weather this time of year has a pretty standard pattern of quickly warming temperatures followed by afternoon thunderstorms that can cool things down.  These storms sometimes provide a good bit of ‘excitement’ and are a prime photo subject.

  • Slideshow updated July 29, 2018

Recreationalists head outdoors and take advantage of urban, suburban and rural opportunities.  As they do, our abundant wildlife that is found just about anywhere comes into focus.

Showcasing images captured by ThorntonWeather.com readers as well as some of our own, our monthly slideshow covers the entire gamut of weather and nature related imagery.   Sunsets, sunrises, wildlife and of course every type of weather condition are vividly depicted.

To learn more about how to send your photo to us for inclusion in the slideshow, see below the slideshow.

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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Out of the office for a few days

Tuesday, July 31st, 2018 2:00pm MST

Time for a break!  We’ll be largely incommunicado for a few days while getting some much-needed R & R.  The good thing is that the weather looks to be relatively calm while we are gone.  As always, keep an eye on our website for all the latest including real-time conditions, forecasts, and much more.

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Near normal temperatures, lots of sun, calm conditions for Tuesday

Tuesday, July 31st, 2018 5:23am MST

A nice looking day ahead for Thornton. We do warm up a good bit today but not too much so and conditions will be calm and pleasant.

We start out with clear skies and will stay that way for much of the day with only a few clouds arriving around mid-afternoon. Temperatures today will top out in the mid-80s, about five degrees below normal.

Tonight, skies remain mostly clear with lows around 60 degrees.

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Thornton’s workweek starts off cooler than normal, warmer weather lies ahead

Monday, July 30th, 2018 5:00am MST

We will enjoy one more day with temps a good ways below normal for this time of year. The rest of the week will feature warming temperatures with most days seeing highs right near average.

For today, we start out with a good bit of cloud cover. That will be easing by mid-morning and by the evening we will have mostly clear skies. Temperatures today will top out in the mid-70s, about 15 degrees below normal. At this time, we don’t expect to see any showers or thunderstorms in our area.

Tonight, skies will continue to clear with lows in the mid-50s.

Looking ahead, high pressure returns and that will help drive temperatures higher. Tomorrow will see highs in the mid-80s then the rest of the week will feature temps within a few degrees of normal for this time of year (90 degrees). Get more details in the extended weather forecast here.

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