Thornton, Colorado, USA
UpdatedThu, 20-Sep-2018 5:25am MDT 


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Monday’s rain brings big bump in monthly and annual precipitation numbers

Tuesday, July 24th, 2018 5:22am MDT

With 1.80 inches having fallen in the bucket yesterday afternoon and evening, Thornton saw a big boost in our rainfall totals for July and the entire year.

In fact, the 1.80 inches from that one storm was more precipitation than we had seen in any single month yet this year.

It did push the month’s rainfall total to above the 11 year average for July however, for 2018 we are still lagging almost 2 inches below what we would normally see by the end of July.

There are still seven days left in the month and monsoonal flow does look to be present in the coming days so we certainly could see things improve further.

You can check out this chart and other monthly summary reports for other weather data here.

Thornton, Colorado monthly rainfall summary for 2018 as of July 24. (ThorntonWeather.com)

Thornton, Colorado monthly rainfall summary for 2018 as of July 24. (ThorntonWeather.com)

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Thornton’s Tuesday to offer pleasant weather with seasonal temperatures

Tuesday, July 24th, 2018 5:07am MDT

Following yesterday’s drenching (1.80” of rain), we dry out and warm up today.

The day starts with partly clear skies and perhaps a few spots with fog. Clouds and fog will dissipate not long after sunrise leading to mostly sunny skies for most of the day. The afternoon will see a few more clouds.

Temperatures will be topping out close to the average high for the date of 90 degrees.

This evening may bring some isolated, weak thunderstorms but right now it looks like most activity will be to our south.

Overnight tonight, lows will dip to the mid-60s under partly cloudy skies.

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Thornton’s workweek starts off cooler, potentially wetter

Monday, July 23rd, 2018 5:14am MDT

A nice change in the weather for us today as moisture and instability increase giving us a decent chance for precipitation while cooling things down.

The day starts off under cloudy skies and while there may be a slight break or two in the coverage at a few points, for the most part the sky will be covered. Temperatures will be much cooler today with highs topping out in the mid to upper 70s.

For precipitation, a few light showers maybe possible this morning but most of the activity looks to begin around noon with scattered activity then increase in coverage in the afternoon and evening. Some brief, heavy rain with perhaps a bit of hail may be seen along with gusty winds.

Tonight, storm activity should be done by midnight and we will see overnight lows around the 60 degree mark.

Looking ahead, tomorrow we should bounce back with temps near normal and dry conditions. The balance of the week though looks to be a bit cooler than normal with some chances for storms each day. Get more details in the extended weather forecast here.

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Thornton’s weekend to start hot, then cool a bit and bring better chances for storms

Friday, July 20th, 2018 5:29am MDT

Hang in there. We see a couple more days with unseasonably warm temperatures then things should cool down and temps near normal can be expected over the longer term.

For Friday, mostly sunny skies will be above with the usual afternoon and evening increase in cloud cover. Temperatures will climb and top out in the mid-90s. We have just a slight chance for thunderstorms in the late afternoon and evening. Tonight, skies remain partly clear with lows in the mid-60s.

Saturday will see a few more clouds throughout the day as moisture increases. Temperatures will still be quite warm with highs in the mid-90s. We do see a better chance for showers in the afternoon and evening tomorrow. Saturday night into Sunday morning, mostly cloudy skies will be above with lows in the mid-60s.

The weekend closes out on Sunday with mostly cloudy skies above and temperatures coming close to normal for the date (90 degrees). We stand a decent chance to see some shower activity.

Previewing next week, Monday should be a good bit cooler as a cold front will have moved through. Then we do rebound but temperatures should stay close to normal.

Have a great weekend!

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The heat is on for Thornton’s Thursday as temps will push to near 100.

Thursday, July 19th, 2018 5:03am MDT

Today will be a good day to spend the afternoon inside. High pressure will dominate keeping any moisture at bay and allowing the mercury to push close to record-setting territory.

We start out with sunny skies then by mid-afternoon will see just a few clouds. Winds will be calm most of the day but we may see some gusty conditions in the late afternoon.

As for temperatures, Denver’s record high for today’s date is 101 degrees set in 2005. We should be topping out today pretty close to that.

Tonight, skies remain mostly clear with lows in the mid-60s.

Keep an eye on the temperature here.

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July 15 to July 21: This week in Denver weather history

Wednesday, July 18th, 2018 4:03pm MDT
This week in Denver weather history

July 15 to July 21: This week in Denver weather history

Denver’s weather is rarely boring and our look back at this week in Denver weather history shows that. There have certainly been many notable thunderstorms with hail and damaging wind. However the most interesting item is the first – and only – recorded instance of snow during the month of July in the Mile High City.

From the National Weather Service:


In 1934…a streak of 15 consecutive days of 90 degrees ranked 5th on the list of hot streaks. The record of 24 consecutive days was established in the summer of 2008.

In 2008…a streak of 24 consecutive days of 90 degrees shattered the previous record of 18 consecutive days established in 1901 and 1874. Ironically…no new single day record high temperatures were set in the month of July. In August however…a record of 104 degrees was set on the 1st…and another record of 103 degrees was set on the 2nd. In addition…a record low min of 70 degrees was set on August 2nd.


In 1985…thunderstorms dumped heavy rain and hail at numerous locations along the Front Range from Denver north. Some of the heaviest rain fell in northern and western suburbs of Denver. Up to 2.6 inches of rain drenched Arvada…and Thornton was soaked with 2 inches in 45 minutes. At least 5 homes in Arvada suffered extensive damage from water and mud…and many streets and basements were flooded. In southern Jefferson County…11 homes were struck by lightning.


In 1879…a terrific hail storm occurred in the vicinity of Buffalo Station on the south park railroad in the South Platte River canyon about 39 miles south of Denver. Stones as large as hen’s eggs fell thick and fast and broke nearly every pane of glass in the windows of the building. A “waterspout” or cloudburst caused much loss of property from flash flooding on a nearby gulch. The torrent of water caused a deafening roar as it uprooted trees and carried huge Boulders and other debris. It struck the house and sawmill simultaneously and carried them away like straws…leaving little behind. The water continued to rush down the gulch for several hours. Serious damage was done to the south park railroad. The track and roadbed were destroyed for several miles. At about the same time…heavy rains in the vicinity of the headwaters of Cherry Creek produced a rapid rise in the creek…which drowned a few head of cattle and washed away two footbridges and some fences. Only 0.10 inch of rainfall was recorded in Denver.

In 1896…a thunderstorm produced sustained southwest winds to 40 mph with gusts to 46 mph.

In 1902…the temperature reached a high of 100 degrees in downtown Denver…which was a record maximum for the date.

In 1929…a thunderstorm did considerable damage to property in the eastern portion of the city. Heavy hail ranging in size from 1/4 to 3/4 inch in diameter…severe lightning… And high winds accompanied the heavy rain. Basements were flooded…and streets were impassable in places for several hours due to the heavy rainfall. Lightning damaged several telephone poles. Hail did extensive damage to gardens and flowers. The hail was up to a foot deep in places. There was no estimate of damage from the storm. A thunderstorm produced only a trace of rain and east winds to 24 mph in downtown Denver.

In 1959…thunderstorm rain totaled 0.41 inch in 8 minutes and winds gusted to an estimated 50 mph near downtown Aurora where half inch diameter hail was also reported. After the storm moved to the east…complete double rainbows were observed from the weather bureau office at Stapleton Airport.

In 1962…hail pelted the area in Adams County around Henderson and Brighton…causing extensive damage to corn…grain…beets…and row crops. Crop damage was estimated at 250 thousand dollars.

In 1963…a man received severe burns when struck by lightning while painting a building in south Denver.

In 1965…a state patrolman sighted a tornado near Bennett. It touched down over open ground…but caused no damage.

In 1967…heavy rains flooded streets and underpasses in south Denver. Heavy rain and minor wind damage were reported in wheat ridge…Aurora…Englewood…and Littleton. Basements were flooded and power disrupted. The clouds and rain resulted in a high temperature of only 72 degrees…which was a record low maximum for the date.

In 1974…a severe lightning storm damaged several homes and caused a number of power outages in both Denver and western Arapahoe counties.

In 1975…lightning killed a girl west of Boulder.

In 1982…winds gusted to 60 mph at Stapleton International Airport…and strong winds blew down walls at a construction site in Aurora where a nearby tree was uprooted.

In 1985…0.79 inch of rain fell in 30 minutes at Castle Rock. Much of the town lost power when lightning struck the town’s transformer.

In 1992…a man was struck by lightning while horseback riding near Castle Rock. Two people were struck by lightning near Highlands Ranch in south metro Denver. A man was struck by lightning while riding in the back of a pick-up truck in Franktown. All received minor injuries. Strong thunderstorms moved through east metro Denver…producing large hail and flash flooding. Hail up to 1 1/4 inches in diameter fell near Buckley Air National Guard base. Rainfall of 1 to 3 inches fell in Aurora in less than an hour…leaving water up to 18 inches deep in some areas. Thunderstorm rainfall was measured at 0.97 inch at Stapleton International Airport…where 3/8th inch diameter hail fell and south winds gusted to 44 mph.

In 1993…dime size hail fell in Golden. National weather service observers at Stapleton International Airport sighted a small rope-like funnel overhead for about 3 minutes before it dissipated.

In 1994…a small…short-lived tornado caused damage to a house under construction in Parker.

In 1995…thunderstorm winds of unknown strength downed trees and branches…damaging a porch and nearby cars in Denver.

In 1998…hail to 7/8 inch in diameter fell near Keenesburg.

In 2000…this date marked the end of a near record hot streak for metro Denver. The high temperature at Denver International Airport equaled or exceeded the 90-degree mark for 17 consecutive days…from June 29th. This was one day short of equaling the all time record. The record of 18 consecutive days was set in two different years…July 1st-18th…1874 and July 6th-23rd…1901.

In 2005…severe thunderstorms produced large hail over southeast metro Denver. Hail as large as 1.75 inches in diameter fell in southwest Aurora along with 7/8 inch hail in centennial. Hail to 3/4 inch in diameter was measured near centennial airport and near Watkins.

In 2015…A severe thunderstorm produced a peak wind gust to 60 mph from the northwest at Denver International Airport. In addition…0.06 inches of rainfall was also observed.

In 2016…large hail ranging in size from 1 to 2 inches in diameter struck Aurora…Castle Rock…Centennial…Greenwood Village and southeast Denver. The hail shattered


In 2006…a brief mid July hot spell resulted in two 100 plus degree high temperatures and two daily maximum temperature records. The high temperature climbed to 101 degrees on the 15th and 103 degrees on the 16th at Denver International Airport.


In 1911…thunderstorm winds were sustained to 44 mph from the northwest.

In 1959…a thunderstorm produced 3/8 inch diameter hail and a wind gust to 60 mph at Stapleton Airport.

In 1972…two tornadoes were sighted by the public to the southeast of Aurora. No damage was reported.

In 1978…a thunderstorm wind gust to 52 mph was recorded at Stapleton International Airport.

In 1980…a severe thunderstorm ripped through metro Denver… Producing torrential rain…large hail…and strong winds.

In Aurora…winds gusted to 65 mph with hail up to 1 1/2 inches in diameter and half an inch of rain in just 10 minutes. Stapleton International Airport was closed for an hour. Large hail also fell in southeast Denver…Lakewood…Parker… And Castle Rock. Up to 1 1/2 inches of rain fell in just 40 minutes. Heavy rains in wheat ridge flooded a shopping center…breaking windows and doors…while causing 100 thousand dollars in damage. Some roofs and windows were damaged throughout metro Denver. At Stapleton International Airport where west winds gusted to 49 mph…1/4 inch hail and 0.77 inch of rain fell.

In 1983…severe thunderstorms dumped large hail over much of metro Denver. Hail to 3/4 inch in diameter fell in Littleton and Northglenn…with 3/4 to 1 inch hail in Arvada…1 to 1 1/2 inch hail in extreme northwest Denver…1 3/4 inch hail in Lakewood…1 1/2 inch hail in south Arvada and just northeast of Aurora…and 1 5/8 inch hail on green mountain.

In 1994…spotters reported a brief tornado touchdown in an open field just north of Fort Lupton. No damage or injuries were reported.

In 2000…very moist and unstable weather conditions…along with low level upslope flow during the late afternoon and evening…combined to produce heavy thunderstorm rainfall… Which caused urban and small stream flooding across metro Denver. Rainfall amounts generally ranged from 1 to 3 inches with the heaviest rainfall occurring during the evening hours. Two miles east of white ranch in northern Jefferson County… An automated rain gage measured 3.86 inches of rain. Since the rain fell in a relatively open area…no flood damage was reported. However…in greenwood village near the intersection of Peoria and Belleview…the streets were closed for several hours with as much as 2 feet of standing water covering the roadways. Two campers near Mt. Evans were injured by lightning and stranded overnight by the inclement weather. Both received minor injuries.

In 2003…the high temperature of 101 degrees was a record maximum temperature for the date.

In 2004…locally heavy rainfall of unknown amount caused parts of the Virginia Canyon road near Idaho Springs to wash out. The road had to be closed temporarily.

In 2005…the temperature climbed to a high of 102 degrees at Denver International Airport. This was a new record maximum temperature for the date at the time.

» Click here to read the rest of July 15 to July 21: This week in Denver weather history

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Wednesday kicks off a period of hot temps, dry conditions

Wednesday, July 18th, 2018 4:56am MDT

The building of a high pressure ridge will bring a return of the hot, dry conditions we had escaped from. Mercury readings well above normal will begin today and last through the weekend.

For today, we start out under sunny skies then the afternoon brings just a few clouds. Winds will be light and out of the north for most of the day.

As for those temperatures, we start out cool enough but then the mercury will begin a quick rise toward an afternoon high of around 97 degrees.

Tonight, skies remain mostly clear with lows in the low to mid-60s.

Looking ahead, we’ll be even hotter tomorrow then the balance of the week should see temps in the mid-90s. Get more details in the extended weather forecast for Thornton here.

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Temperatures right near normal, another, slight chance for thunderstorms Tuesday

Tuesday, July 17th, 2018 5:08am MDT

Today we’ll see weather not entirely unlike what we experienced yesterday. We start out with some clouds, then will clear, followed by some isolated thunderstorm activity.

Partly clear skies will be above initially with a low layer of stratus clouds. Those will then break up giving us mostly sunny skies for much of the rest of the day following by an increase of coverage in the afternoon and evening.

Temperatures today will top out right near the average high for today’s date of 90 degrees. Some thunderstorm activity can be expected in the area from mid-afternoon into the evening. Most though will unfortunately be to our north.

Tonight, partly clear skies will be above and lows will dip to the low 60s.

Keep an eye out for any storms with our interactive radar here.

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Thornton’s workweek starts off with seasonal temps, slight chance for storms

Monday, July 16th, 2018 5:01am MDT

Yesterday offered up cloudy and cool conditions. Today we rebound with more sun and temps near normal. The morning starts out with some cloud cover and a bit of fog in a few areas.

A Dense Fog Advisory is in effect until 8:00am so please be aware and slow down if you encounter areas with limited visibility. Once that lifts, we will enjoy mostly sunny skies for most of the balance of the day.

Temperatures will top out today in the upper 80s, close to the average for today’s date of 90 degrees. The late afternoon into the evening bring just a slight chance for thunderstorm activity although right it looks like most will be in the high country.

Tonight, partly clear skies and lows in the low 60s can be expected.

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Thornton to enjoy a largely seasonal weekend, some chances for storms

Friday, July 13th, 2018 5:10am MDT

A pretty nice looking three-day period ahead for us. Saturday will see a return of the heat but Friday and Sunday will be cooler and have some chances for storms.

For today, mostly sunny skies will be above. Thunderstorm activity will be mostly relegated to the mountains but there is a slight chance we could see something in the late afternoon / evening. Highs today will be in the mid to upper 80s. Overnight tonight, lows will be in the low 60s.

Tomorrow will be the warmest day of the weekend with highs reaching toward the mid-90s. Mostly sunny skies will be above. There will be just the slightest of chances for an evening thunderstorm. Saturday night into Sunday morning, temps will dip to the mid-60s.

For Sunday, we will see a few more clouds above than the other days. Daytime highs should be in the mid-80s. The afternoon and evening bring a chance for some thunderstorms.

Have a great weekend!

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