Thornton, Colorado, USA
UpdatedThu, 17-Aug-2017 3:30am MDT 


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June 2017 weather recap: Month offers up warmer, drier than normal conditions

Friday, July 7th, 2017 8:51am MDT

High pressure was the general rule for much of the month of June 2017.  This resulted in overall average temperatures that were warmer than normal and precipitation that fell a good ways short of average.

The month was largely short on weather excitement, beyond the temps and lack of precipitation.  The National Weather Service said that 23 of the 30 days saw above normal temperature readings.  Denver recorded only five days with precipitation while in Thornton we saw eight.

Thornton saw an overall average monthly temperature of 69.2 degrees.  Out at DIA where Denver’s official measurements are taken, the Mile High City was close with an average of 69.5 degrees.  Both locations’ readings were well above the long term June average of 67.4 degrees.

Temperatures in Thornton ranged from a high of 98.7 degrees on the 21st down to a low of 46.3 degrees on the morning of the 24th.  Denver saw a maximum of 99 degrees on the 20th and a low of 42 degrees on the 13th.

In terms of precipitation, Denver averages 1.98 inches during the month of June. Thornton fell short of the mark with 1.20 inches falling into our rain bucket while Denver’s reading was far worse with a mere 0.33 inches falling there.

Neither Thornton nor Denver saw any snowfall during the month.

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

Thornton, Colorado's June 2017 temperature summary. (ThorntonWeather.com)

Thornton, Colorado’s June 2017 temperature summary. (ThorntonWeather.com)

Thornton, Colorado's June 2017 precipitation summary. (ThorntonWeather.com)

Thornton, Colorado’s June 2017 precipitation summary. (ThorntonWeather.com)

From the National Weather Service:

729 AM MDT SAT JUL 1 2017




                 VALUE   DATE(S)  VALUE   FROM    VALUE  DATE(S)
 HIGH             105   06/26/2012
  LOW              30   06/02/1951

HIGHEST            99   06/20        96       3       98  06/21
LOWEST             42   06/13        42       0       49  06/02
AVG. MAXIMUM     85.5              82.4     3.1     85.5
AVG. MINIMUM     53.6              52.3     1.3     56.2
MEAN             69.5              67.4     2.1     70.8
DAYS MAX >= 90      9               7.9     1.1       12
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 4.96 1882
 MINIMUM T 1890 
TOTALS 0.33 1.98 -1.65 1.62 
DAILY AVG. 0.01 0.07 -0.06 0.05 
DAYS >= .01         5               8.4    -3.4        7
DAYS >= .10         2               4.6    -2.6        4
DAYS >= .50         0               1.4    -1.4        1
DAYS >= 1.00        0               0.3    -0.3        0
 24 HR. TOTAL    0.13   06/29 TO 06/29           06/13 TO 06/13

RECORD            0.5 1953
 TOTAL            0.0 2017          0.0

HEATING TOTAL      25                62     -37        4
 SINCE 7/1       5109              6058    -949     5560
COOLING TOTAL     167               133      34      185
 SINCE 1/1        173               155      18      188

 EARLIEST     09/08/1962
 LATEST       06/08/2007
EARLIEST      04/01             10/07
LATEST        05/04             05/05

AVERAGE WIND SPEED              10.1

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


THUNDERSTORM             10     MIXED PRECIP               0
HEAVY RAIN                2     RAIN                       2
LIGHT RAIN                8     FREEZING RAIN              0
LT FREEZING RAIN          0     HAIL                       0
HEAVY SNOW                0     SNOW                       0
LIGHT SNOW                0     SLEET                      0
FOG                       3     FOG W/VIS <= 1/4 MILE      0
HAZE                      1

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Thornton’s weekend to remain mild, offer a couple chances for storms

Friday, July 7th, 2017 5:10am MDT

We will get a little bit of a break from the heat Friday and Saturday and see some chances for thunderstorms. Unfortunately, the mercury will once again be climbing come Sunday however.

For today we will enjoy mostly sunny skies for the morning to be followed by an increase in clouds in the afternoon due to elevated moisture levels aloft. Winds will be calm initially then become gusty in the afternoon. We do see chances for thunderstorms this afternoon and evening, primarily between about 2:00pm and 5:00pm. Highs today will be the low 90s then tonight temperatures dip to the low 60s.

Saturday’s weather will be much like today but, with any luck, a few degrees cooler. Again, mostly sunny skies will be above and the afternoon and evening will bring slight chances for thunderstorm activity. Highs will be the upper 80s. Overnight Saturday into Sunday morning lows will be down to the low 60s.

Sunday, things dry out and the heat returns. Sunny skies will be above as we head for a high in the mid-90s.

Looking into next week, highs in the 90s look to be the general rule at least for the first half of the week.

Have a great weekend and of course keep an eye on http://www.thorntonweather.com for all the latest.

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Pence Vows: ‘American Boots on the Face of Mars’

Thursday, July 6th, 2017 8:04am MDT

U.S. Vice President Mike Pence pledged to usher in a “new era” of American leadership in space during a tour of the Kennedy Space Center in Florida Thursday. “Our nation will return to the Moon, and we will put American boots on the face of Mars,” Pence told the cheering crowd of about 800 NASA employees,… » Click here to read the rest of Pence Vows: ‘American Boots on the Face of Mars’

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July 2 to July 8: This week in Denver weather history

Thursday, July 6th, 2017 6:50am MDT
This Week In Denver Weather History

July 2 to July 8: This Week in Denver Weather History

In our July weather preview we discussed how the month is not only Denver’s hottest but also its stormiest. Our look back at this week in Denver weather history helps to illustrate that fact. We start seeing 100+ degree days as well as many of the types of fast moving thunderstorm events expected this time of year.

From the National Weather Service:


In 1990…almost a year to date after the record breaking heat in early July 1989…the third longest heat wave in Denver history started. From June 29th through July 2nd the temperature reached 100 degrees or more on four consecutive days. The highest reading of 102 degrees occurred on the 29th…30th…and 1st. Combined with the 102 degree reading on June 27th this would have been the longest heat wave on record…but the temperature climbed to only 98 degrees on June 28th.


In 2000…the 29th marked the beginning of a near record hot streak for metro Denver. The high temperatures…as recorded at Denver International Airport…exceeded the 90 degree mark for 17 consecutive days from June 29th through July 15th. The record of 24 consecutive 90 degree or above days was set from July 13th through August 5th…2008.


In 1874…a streak of 18 consecutive days of 90 degrees tied for second with another streak that was later set in the summer of 1901. The record of 24 consecutive days was established in the summer of 2008.


In 2012…it was the hottest July on record in Denver since weather records began in 1872. The average temperature for the month was 78.9 degrees which was 4.7 degrees above normal. There were 27 days in which the high temperature equaled or exceeded 90 degrees…which established a new record. There were also 7 days in which the temperature equaled or exceeded 100 degrees which tied the record set in 2005.


In 1879…a severe hail storm produced considerable damage in the vicinity of Arvada. Some of the stones were unusually large…measuring 6.5 inches in circumference (2 inches in diameter) with an average weight of 1 ounce. The stones were uniformly large with one side concave. The greatest damage was to early wheat…cabbage…and vines. A tree just to the south of the weather station in downtown Denver was struck by lightning. Residents in the house 15 feet away were affected by the strike.

In 1885…thunderstorm winds were sustained to 50 mph in the city.

In 1892…an apparent cold front produced sustained northeast winds to 40 mph with gusts to 45 mph.

In 1955…a apparent microburst wind gust to 69 mph was recorded at Stapleton Airport where the brief strong wind reduced the visibility to zero in blowing dust.

In 1965…hail…up to 2 inches in diameter…struck southwest Adams and northeast Denver counties…damaging cars…windows… And foliage. Hail accumulated up to a foot deep. Wind gusts to 48 mph and hail to 1 inch in diameter fell at Stapleton International Airport where the large hail broke three storm windows and shredded shrubs at the U.S. Weather Bureau Upper Air building.

In 1968…a pilot reported a tornado 10 miles southeast of Parker.

In 1971…one inch diameter hail stones were reported in Adams County about 30 miles east of Denver.

In 1987…a large tornado touched down 10 miles northeast of Stapleton International Airport. The tornado was vertical and thick and kicked up a large dust and debris cloud. Later…it developed a sinuous rope-like shape as it slowly dissipated. The tornado was visible for 15 minutes. The twister occurred in open country and did only minor damage to a metal shed…porch…and mailbox. A man was killed by lightning in southwest Aurora. He was in his backyard and had a shovel in his hand at the time of the strike. A group of soccer players were hit by lightning on a field in Boulder. A 10-year-old boy was critically injured and hospitalized; fortunately he recovered. Six other people were knocked to the ground by the strike. Two of these were slightly injured. Golf ball size hail fell just east of Littleton and at Highlands Ranch. Hail as large as 3/4 inch in diameter was reported in Aurora and Parker and near Hudson and Franktown.

In 1988…a 45-year-old man was injured by lightning at Cheery Creek Reservoir. Administration of CPR probably saved his life.

In 1990…the temperature reached a high of 100 degrees at Stapleton International Airport.

In 1993…thunderstorm winds blew a roof off a barn near Parker…causing an estimated 15 hundred dollars damage.

In 1994…thunderstorm winds downed power lines in Boulder… Causing power outages. Winds gusted to 66 mph in Boulder… 64 mph in Arvada…and 60 mph in Golden.

In 1998…a small tornado touched down briefly near Barr Lake… But caused no damage.

In 2002…hail as large as 1 3/4 inches in diameter fell in the city of Denver and in Arapahoe County near Littleton. The low temperature of 69 degrees equaled the record high minimum for the date.

In 2006…lightning struck a teenager in Castle Rock as he was mowing his lawn and listening to an iPod. The teen suffered burns to his hands and feet…and had blood running from his ears when he was found. The victim’s eardrums were ruptured…which damaged his hearing. Lightning also struck a house in Castle Rock causing extensive damage to the roof and side of the home. Heavy rains caused flash flooding at Castlewood Canyon State Park near Franktown. The floodwaters destroyed four footbridges along the high trail. A culvert and several roads were washed out in the area. In addition… Two driveways crossing Cherry Creek were washed out near Prairie Canyon Ranch. Heavy rainfall also caused minor flooding on murphy and sand creeks…just east of Buckley AFB. Gun Club Road was closed between Alameda and Mississippi avenues…north of the Murphy Creek Golf Course…where 3 feet of standing water reportedly covered the road. A severe thunderstorm produced large hail to 7/8 inch in diameter in south Aurora near Cherry Creek.


In 1874…the temperature climbed to a high of 101 degrees in downtown Denver.

In 1881…the all time highest recorded daily minimum temperature of 77 degrees occurred in the city. This was also the highest daily minimum temperature ever recorded in July.

In 1885…a severe thunderstorm produced hail the size of hazel nuts…which fell with great force. A telegraph pole in west Denver was struck by lightning and shattered to pieces.

In 1955…a brief microburst wind gust to 61 mph was recorded at Stapleton Airport.

In 1960…a major hail storm caused 1.5 million dollars in damage across metro Denver. The heaviest damage occurred in south Denver…Englewood…Littleton…and Golden from wind- driven hail as large as golf balls and heavy rain which caused flooding. Winds were estimated at 60 to 70 mph. Rainfall was estimated at 2 to 3 inches. Hail accumulated 3 to 4 inches deep in some sections. Hail carried by flood waters drifted 3 to 4 feet deep. An Englewood policeman was injured when hail broke the windshield of his car. One inch of rain in 10 minutes…and heavy hail damage were reported in Parker. At some places the hail from the storm was still on the ground the next morning.

In 1967…large hail stones from 1 3/4 to 2 1/2 inches in diameter damaged cars and buildings in southwest Denver and Littleton where hail drifted to depths of 3 to 4 feet. The hail caused a great deal of damage…and streets were flooded by heavy rain over many sections of west metro Denver. At centennial race track near Littleton…a few hail stones were as large as tennis balls. Large hail broke the windshield on a Littleton police car. Golf ball to tennis ball size hail fell in the vicinity of Arapahoe road and south Broadway. One inch diameter hail fell at the intersection of orchard and south university. Golf ball size hail fell in Broomfield. Hail in Westminster was measured from 1 to 1 1/4 inches in diameter. Tornadoes were sighted by the public near Cheery Creek Reservoir… north of Commerce City…and in Arvada…but caused no reportable damage.

In 1993…high winds developed behind a strong cold front along portions of the Front Range. While the strongest winds were reported north of metro Denver…the winds blew out a half inch thick pane of glass from a vacant 9-story building. The glass landed on a parked car below. West winds gusting to 52 mph kicked up some blowing dust at Stapleton International Airport.

In 1996…lightning sparked a small fire near buffalo creek in southern Jefferson County. Only one acre burned before the fire was contained.

In 2002…heavy thunderstorm rain washed out a frontage road 6 miles north of Larkspur. The nearby mountain ranch subdivision was also flooded. Heavy rainfall in the Hayman fire burn area washed out a secondary road when debris from the runoff blocked a culvert. Hail as large as 3/4 inch fell near Keenesburg…in Castle Rock…and 7 miles to the south of Castle Rock.

In 2005…severe thunderstorms produced high winds. Wind gusts to 75 mph were measured near Longmont and to 60 mph just west of Boulder. No damage was reported.

In 2007…severe thunderstorms produced large hail in the foothills and suburbs west of Denver. Large hail from 1 to 2 inches in diameter was reported in the vicinity of Idaho Springs…Rollins and Edgewater.

In 2009…severe thunderstorms produced large hail and north and east of Denver. Hail up to one inch in diameter was observed near Erie and firestone. Hail up to 1 3/4 inches was observed 5 to 6 miles west-southwest of Byers. The golfball size hail caused extensive damage to a wheat field. In Aurora…six children received minor injuries when lightning struck a nearby tree. The injuries occurred when they were knocked down by the blast. None of the children suffered burns or appeared to have been directly hit by lightning.

In 2014…a severe thunderstorm produced large… up to 1 ½ inches in diameter…about 14 miles northwest of Golden.

4 » Click here to read the rest of July 2 to July 8: This week in Denver weather history

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Another hot one in Thornton Thursday, slight chance for thunderstorms

Thursday, July 6th, 2017 4:58am MDT

No appreciable break in the heat for us today. The high pressure ridge that keeps us locked in the same pattern remains in place and will once again lead to temperatures well above normal.

We start out with sunny skies then see a few clouds by mid to late morning and continuing to increase in coverage slowly in the afternoon. Temperatures are starting out quite mild and this will aid in their daytime climb. Highs today will be in the mid to upper 90s, well above the average of 89 degrees for the date.

Late afternoon and evening introduce just the slight chance for isolated thunderstorms. Strong, gusty winds will be the biggest threat from any storms we see.

Keep an eye on the thermometer here.

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July weather preview: Hot temps, storms typically the highlight

Wednesday, July 5th, 2017 12:43pm MDT

Change is of course the one constant in Denver’s weather but come July, things actually get pretty consistent.

The standard formula for a day in July is a sunny morning, clouds developing in the late morning and early afternoon. Come mid-afternoon, thunderstorms are rolling off of the foothills and into the metro area and the eastern plains. These storms do occasionally reach severe status containing hail, gusty winds and heavy downpours of rain.

Check out our July weather preview for a complete look at what is in store for the month ahead.

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Lots of sun and heat on tap for Thornton’s Wednesday

Wednesday, July 5th, 2017 4:59am MDT

High pressure will continue to dominate today and there will be a distinct lack of moisture. Those factors will help to drive us toward high temperatures far above normal today and bring some of our hottest readings of the year so far.

The day dawns with sunny skies and we will see plenty of sun throughout the day other than a few clouds in the afternoon and evening. Winds will be light and out of the southwest initially then shifting to out of the east in the afternoon.

Temperatures will be the main focus of today’s weather. Look for the mercury to steadily climb toward a mid to late afternoon high of 97 degrees. The average high for today’s date is 88 degrees.

Tonight, skies will be mostly clear and lows dip into the mid-60s.

You can keep an eye on the temperature with our live gauges here.

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Thornton set to enjoy a firecracker hot Independence Day

Tuesday, July 4th, 2017 5:13am MDT

The heat is on for our Fourth of July thanks to high pressure being centered over the state. Temperatures are going to be well above normal and while we may see a few thunderstorms, they should be done by the time dark comes and the fireworks start going off.

We start out with sunny skies then will see a few more clouds as the day progresses, much like what we saw yesterday. Winds will be a bit breezy in the mid to late afternoon. Temperatures today are going to climb fast and head toward a high in the low to mid-90s.

We do once again have slight chances for thunderstorms from mid-afternoon into the early evening. Like recent days, strong winds will be the biggest threat from these along with lightning so if you are outside, please be aware.

You can keep an eye out for the storms here.

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Monday brings very warm temperatures, only a slight chance for storms

Monday, July 3rd, 2017 5:08am MDT

For a lot of folks today is a day off, offering them a four day weekend. If so, you will be able to enjoy a nice day but one that will be quite warm.

We start out with mostly to partly sunny skies and will similar for the majority of the day. Winds will be out of the north and relatively light. Temperatures will be warming quickly as we head for a high in the low 90s, a bit above the average of 88 degrees for the date.  The late afternoon may see a few, isolated thunderstorms develop but activity will be short-lived and the evening pleasant.

Overnight lows tonight will drop to around 60 degrees under partly cloudy skies.

Enjoy the day!

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Thornton’s Friday and weekend starts cool, then warms up

Friday, June 30th, 2017 5:00am MDT

Following a night that saw us get a nice little bit of rain, we will remain cloudy and on the cool side today. Saturday and Sunday though promise warmer and drier weather.

For today we start out with mostly cloudy skies then will see some easing of the coverage in the afternoon and evening. A few light showers will be possible this morning into the afternoon. Temperatures will be a good bit cooler today with highs in the low 70s. Overnight tonight look for partly cloudy skies and lows in the low to mid-50s.

Tomorrow will be the sunniest and driest of the three day period. Sunny to mostly sunny skies will be the general rule Saturday as we head toward a high in the mid to upper 80s. We should remain dry. Saturday night into Sunday morning will be partly cloudy with lows in the mid to upper 50s.

Sunday closes out the weekend with the warmest day of the period. Highs will be around the 90 degree mark under mostly sunny skies. The afternoon does introduce just a slight chance for thunderstorms.

Have a great weekend!

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