Thornton, Colorado, USA
UpdatedFri, 25-Jul-2014 2:30pm MDT 


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Thornton’s Friday and weekend to feature two hot days, then cooler temps arrive

Friday, July 25th, 2014 6:36am MDT

Are you tired of the recent heat?  If so then hang on for a couple more days – a trend toward cooler mercury readings is set to arrive.

For Friday we are going to close out the workweek with temperatures right near the average for the date of 90 degrees.  Partly sunny skies will be above.  Thunderstorms and showers are again expected to develop this afternoon, possibly with greater coverage than what we saw yesterday.  Gusty winds and brief heavy rain will be possible.

Saturday will see more sun above and temperatures a degree or two warmer than today.  PM thunderstorms will again be possible but are expected to be more isolated than what we see today.

A cold front will be moving in later Saturday and that is going to bring the break from the heat.  In fact, over the longer term, those colder temperatures are expected to linger well into next week.

Sunday’s high temperatures are expected to be in the mid-80s and we will have a slight chance for thunderstorms.  For much of the next workweek, highs will remain cooler than normal, many days only around 80 degrees.

See the image for your weekend weather outlook and monitor http://www.thorntonweather.com throughout the period for the latest.

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July 20 to July 26: This Week in Denver Weather History

Friday, July 25th, 2014 5:50am MDT
This Week In Denver Weather History

July 20 to July 26: This Week in Denver Weather History

Heavy rain events become more commonplace as we get further into Colorado’s monsoon season. Our look back at this week in Denver weather history contains many examples of the damage these fast-moving events can cause.

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 1987…a streak of 16 consecutive days of 90 degrees ranked 4th on the list of hot streaks. The record of 24 consecutive days was established in the summer of 2008.


In 2005…the high temperature climbed above 100 degrees on each of the 5 days with readings of 101 on the 19th…105 on the 20th…104 on the 21st…and 102 on both the 22nd and 23rd. A new record maximum temperature for the month of July of 105 degrees was set on the 20th…which also equaled the all-time record maximum for Denver of 105 degrees first set on August 8th in 1878. Daily maximum temperature records were set on each day…and the 5 day period equaled the record for the most consecutive days of 100 degrees or more first set from July 4th through 8th in 1989. The intense heat resulted in a high use of electricity for cooling purposes. The demand for electric power exceeded the supply and rolling black-outs… Each lasting about an hour…were scheduled across metro Denver during the afternoons and early evenings.


In 1898…an apparent thunderstorm produced sustained northwest winds to 45 mph with gusts to 51 mph.

In 1939…the high temperature reached 102 degrees in downtown Denver. This was the highest temperature recorded since August 8…1878…a period of 61 years…and the third highest temperature of record at the time. Six miles to the east… At Denver municipal airport…the maximum temperature reached 104 degrees. A dry period during mid-July…combined with low relative humidities…resulted in an unusually large number of forest fires in the mountains west of Denver.

In 1941…an afternoon thunderstorm caused two lightning deaths. The men were struck by lightning near the Denver airport.

In 1951…a thunderstorm wind gust to 54 mph was recorded at Stapleton Airport.

In 1965…heavy rain west of Denver damaged roads and bridges. Two bridges in Golden were washed out. Lightning in Denver caused some power failures and fires…mostly in the northeast section of the city. Heavy rain caused street flooding in the city of Denver. Hail as large as 1/2 inch in diameter and 0.40 inch of rain in 5 minutes were measured at Stapleton International Airport where precipitation totaled 1.09 inches. Lightning damaged a house in Littleton…and caused a power outage in Idaho Springs.

In 1973…lightning damage was reported west of Arvada.

In 1975…heavy rains caused flash flooding across metro Denver…resulting in the closing of several streets and damage to numerous homes and businesses. Hail 1/2 to 3/4 inch in diameter was reported.

In 1976…heavy thunderstorms caused flooding of streets in southeast Denver and western Arapahoe counties. A total of 3.35 inches of rain was measured at Kassler southwest of Littleton.

In 1978…a girl was injured by lightning at a country club southwest of Denver.

In 1984…heavy rain was reported just east of Buckley Field in Aurora where 1.15 inches fell in just 45 minutes.

In 1986…thunderstorms dumped heavy rain across metro Denver causing extensive street flooding…power outages…and basement flooding. The greatest recorded rainfall was 4.39 inches in Lakewood. In extreme northwest Denver…2.29 inches of rain fell in just 20 minutes. Arvada was drenched with 2.60 inches of rain…and over an inch fell in southeast Denver and adjacent sections of Aurora.

In 1990…heavy thunderstorm rains caused flash flooding in sections of Littleton where 1.20 inches of rain fell in less than 30 minutes. The deluge caused dry creek to jump its banks…causing damage to residential streets…curbs…and sidewalks. Nearly 100 vehicles were stranded for a time in fender-deep water when sewers and drainage ditches became choked with debris. The heavy runoff submerged many Littleton streets and intersections.

In 1992…strong thunderstorms moved slowly through east metro Denver…producing rainfall up to 2.50 inches in a short time. Weather spotters reported 0.75 to 1.00 inch of rain in less than 30 minutes. Many areas of southeast Denver were flooded…including I-25 where up to 6 feet of water filled some underpasses. Hail to 3/4 inch in diameter fell in Aurora.

In 1995…a tornado touched down briefly in an open field near Strasburg. Thunderstorm winds gusted to 58 mph at Centennial Airport.

In 1996…strong thunderstorm winds damaged the building of a telephone installation company in the city of Denver.

In 1998…the high temperature reached 100 degrees at Denver International Airport.

In 2006…heavy rainfall in the overland wildfire burn area caused minor flash flooding in Jamestown. The roads behind the Jamestown fire hall were washed out…when a culvert was blocked by debris. A rockslide was also reported in town.

In 2009…a severe thunderstorm produced damaging winds…large hail and very heavy rain across the western and southern suburbs of Denver. Widespread damage was observed in the cities of Arvada…Lakewood and Wheat Ridge. The intense straightline winds were the result of a wet microburst which downed hundreds of trees and snapped power poles. Wind gusts to 80 mph were reported along with hail up to 1 3/4 inches in diameter. The combination of wind and hail caused widespread damage to homes and vehicles. The damage claim estimates totaled 350 million dollars; about 32900 claims were filed for homes…while another 19500 claims were filed for vehicles. As many as 90000 homes and businesses were left without power. In some areas it took up to 3 days to completely restore electrical service. Minor injuries were reported from broken glass during the storm…but no one was hospitalized. The storm crippled the computers at the Colorado crime information center in Lakewood for nearly 3 hours. One weak tornado touched down near Parker but did no damage. In southern Weld County… Severe thunderstorms produced widespread damage over 150 square miles of farmland. In all…400 farms were directly impacted by severe weather. Damage to crops alone was estimated to 3 million dollars. At Denver International Airport…a peak wind gust to 48 mph was observed from the northeast. In addition…1.01 inches was measured at the airport.


In 1961…unusually cool weather for July resulted in several temperature records. Record minimum temperatures were set or equaled on each day with readings of 51…51…49… And 49 degrees. High temperature of only 64 degrees on the 21st was a record low maximum for the date.


In 1965…heavy showers and thunderstorms doused metro Denver with significant rain each day. Rainfall for the six days totaled 5.16 inches at Stapleton International Airport. Massive rainfall occurred on the 20th…21st…and 25th… Flooding streets and basements and causing streams to overflow. The heaviest rainfall…2.05 inches…at Stapleton International Airport occurred on the 25th.

» Click here to read the rest of July 20 to July 26: This Week in Denver Weather History

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July 2014 top shots: Monthly photo slideshow

Friday, July 25th, 2014 5:29am MDT
July 3, 2014 - A gorgeous July sunset. (LE Worley)

July 3, 2014 – A gorgeous July sunset. (LE Worley)

The month of July typically brings a pretty tried and true daily weather pattern with hot days and afternoon thunderstorms.  Like any month of the year in Colorado, a wide variety of subjects will be presented for photo opportunities.

Flowers are now in full bloom, wildlife is abundant with many creatures showing their young for the first time, and then of course there is the weather.  Scorching heat, damaging thunderstorms, heavy rains and more are all possible during the month.

  • Slideshow updated July 23, 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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Above normal temps remain Thursday, better chance for PM thunderstorms

Thursday, July 24th, 2014 6:02am MDT

Yesterday cooled slightly as Thornton saw a high of 90 degrees, right at the average for the date.  Today should be a couple of degrees warmer and we have a chance to see some thunderstorms in the afternoon and early evening.

Mostly sunny skies start things off but we will be seeing an increase in cloud cover and partly sunny skies for most of the day.  High temperatures will be topping out in the low to mid-90s.

Thunderstorms will be possible beginning this afternoon with the best chances occurring from 2:00pm to 6:00pm.

See the image for today’s planning weather outlook and keep an eye on our radar for those storms here.

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Wednesday temps remain in the 90s, slight chance for thunderstorms

Wednesday, July 23rd, 2014 5:59am MDT

Today’s weather in Thornton looks to be much like that which we have seen the last couple of days but with a slight chance for PM thunderstorms.  It continues to look like it will be Sunday before we see any relief from the heat.

For today mostly sunny skies start things out to be followed by an increase in cloud cover beginning around the noon hour.  The mercury will be climbing once again to a high in the mid-90s.

From about 2:00pm to 8:00pm there is a slight chance for some thunderstorms.  Storms that do develop are only expected to bring some brief rain and gusty winds.

See the image for today’s outlook and check out the extended forecast here: http://www.thorntonweather.com/forecast.php

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Tuesday’s temperatures remain hot, little change expected this week

Tuesday, July 22nd, 2014 5:19am MDT

Thornton’s weather forecast for Tuesday looks much like the conditions we saw Monday.  The notable exceptions are less cloud cover and temperatures a degree or two hotter.

We start out the day with sunny skies and then will see some gradual increase in clouds.  Coverage however is not expected to be as extensive or thick as yesterday and that will help to drive the mercury up.

We’ll be heading for a high temperature in the mid-90s this afternoon.  Thunderstorm activity should stay south of our area.

See the image for today’s outlook and head over to our main page for the latest.

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NCAR launches study of Colorado Front Range ozone pollution

Monday, July 21st, 2014 10:51am MDT
The NSF/NCAR C-130 aircraft, one of the aircraft involved in FRAPPÉ, is based at NCAR’s Research Aviation Facility (RAF) at Rocky Mountain Metropolitan Airport in Broomfield, Colorado. RAF develops and operates instrumented research aircraft for the atmospheric science community. (©UCAR, photo by Carlye Calvin, used with permission)

The NSF/NCAR C-130 aircraft, one of the aircraft involved in FRAPPÉ, is based at NCAR’s Research Aviation Facility (RAF) at Rocky Mountain Metropolitan Airport in Broomfield, Colorado. RAF develops and operates instrumented research aircraft for the atmospheric science community. (©UCAR, photo by Carlye Calvin, used with permission)

Over the past week you may have noticed a relatively persistent ‘drone’ of aircraft over the Denver area and seen a relatively large aircraft flying overhead.  The plane is a specially outfitted C-130 taking part in a major field study of the Front Range’s ozone.

Scientists at the National Center for Atmospheric Research (NCAR) will be using the aircraft, radar, balloons and other sensors and systems in the coming weeks.  The project has many goals including mapping possible sources of ozone pollution and using the data to better interpret satellite data.

From NCAR:


BOULDER – Scientists at the National Center for Atmospheric Research (NCAR) and partner organizations are launching a major field project across the northern Front Range of Colorado this month to track the origins of summertime ozone, an invisible but harmful pollutant.

The researchers will use specially equipped aircraft, mobile radars, balloon-mounted sensors, and sophisticated computer simulations to measure local and far-flung pollution sources. Results from the month-long study will provide needed information to officials seeking to ensure that air in the region is healthy to breathe.

It marks one of the largest research projects to look at summertime air pollution on the northern Front Range, including Denver, which often exceeds federal standards for safe levels of ground-level ozone pollution despite efforts to reduce emissions. Ozone can lead to increased asthma attacks and other respiratory ailments. It also damages vegetation, including crops.

“Our goal is to produce an accurate and detailed view of all the diverse sources of ozone pollution along the Front Range,” said NCAR scientist Gabriele Pfister, a principal investigator on the project. “We want to fingerprint where the pollution comes from and analyze what happens when it mixes in the atmosphere.”

Known as the Front Range Air Pollution and Photochemistry Experiment (FRAPPÉ), the study will track emissions from both human-related activities and natural sources. It will focus on the urban corridor from south of Denver, north to Fort Collins, as well as the adjacent plains and mountains. Scientists also want to determine how much pollution comes from upwind areas, including other states and countries.

Funded through a federal-state partnership, FRAPPÉ is supported by the Colorado Department of Public Health and Environment and by the National Science Foundation, which is NCAR’s sponsor.


To provide additional detail across the region, scientists will closely coordinate FRAPPÉ with a second air quality mission taking place on the Front Range at the same time. DISCOVER-AQ (Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality) is a major study led by NASA that seeks to improve the ability of satellites to usefully assess our air quality.

“What we learn from these flights will help us to better interpret satellite remote sensing of air quality from geostationary orbit in the future,” said NASA scientist Jim Crawford, a principal investigator on DISCOVER-AQ. “It also will help us to define the best combination of instruments on the ground to connect air quality monitoring networks with satellite information.”

The DISCOVER-AQ flights and ground observations will focus on the northern Front Range, while FRAPPÉ will gather measurements from the surrounding region.

In all, approximately 200 scientists, technicians, pilots, and students from around the country will converge on the Front Range for the combined projects.

The researchers will quantify emissions from industrial facilities, power plants, motor vehicles, agricultural operations, oil and gas drilling, fires, and other sources. They also will measure naturally occurring emissions from trees and other plants that then combine with emissions generated by human activity to form ozone and other pollutants.


Colorado, like other states, relies on a limited number of ground-based stations to monitor air quality and help guide statewide policies and permitting. But a full, three-dimensional picture of the processes that affect air quality, including conditions far upwind and high up in the atmosphere, requires a three-pronged approach with measurements from aircraft, satellites, and the ground.

“By bringing together aircraft, satellites, and ground-based instruments, we can analyze the amounts and types of pollutants that are emitted in the Front Range as well as transported from other places, how they evolve, and how air circulation patterns near the mountains move them around,” said NCAR scientist Frank Flocke, a principal investigator on FRAPPÉ.

During the projects, which run from July 16 to mid-August, Front Range residents may notice occasional low-flying research aircraft that are taking measurements of the atmosphere. The aircraft will spiral down at times, taking samples of air as they spiral directly above ground instruments that will be measuring air at the surface and observing the atmosphere above.

Ozone, a principal component of smog, forms from the reaction of hydrocarbons and carbon monoxide in the presence of nitrogen oxides (NOx) and sunlight. It peaks during summer months when sunlight is strongest and air conditions are more likely to be stagnant.

Although the scientists will focus on ozone, they will also measure the size and chemical composition of airborne particles to better quantify particle pollution and track its sources. Microscopic airborne particles can have a major impact on people’s respiratory health.

The data gathered by the projects will go through a quality assurance process and then become publicly available in about six months. Scientists will use the data to begin publishing research results in about a year.


FRAPPÉ and DISCOVER-AQ will use similar payloads for their aircraft. The teams will conduct wingtip-to-wingtip intercomparison flights several times during the project, sampling air in the same place to make sure the instrument readings are comparable.

A network of instruments on towers, rooftops, and other sites will continuously monitor ozone and the gases that react to form it. Other ground-based activities, such as measurements from tethered balloons and from lidars (laser-based radars), will be closely coordinated with the flights. The researchers will draw on forecasts and nowcasts of both weather and air quality from a large number of computer models to assess daily conditions and make final decisions on when to fly and where to gather atmospheric samples.

“This is a unique opportunity for the state to work with others on a study that combines ground-based measurements with aircraft-borne sensing,” said Will Allison, director of the Colorado Department of Public Health and Environment’s Air Pollution Control Division. “It will help us more fully understand complex questions such as the factors contributing to ozone formation in the region. And that will help us continue to implement effective measures to reduce air pollution.”

“FRAPPÉ is a major collaborative study that will produce the most complete picture ever of summertime air pollution on the Front Range,” said Thomas Bogdan, president of the University Corporation for Atmospheric Research, which manages NCAR. “This effort will dramatically advance our understanding of air quality and its potential impacts. The results have the potential to help not only people living on Colorado’s Front Range, but residents of other metropolitan areas with similar conditions, too.”

In addition to NCAR and the Colorado Department of Public Health and Environment, the FRAPPÉ team includes scientists from the National Oceanic and Atmospheric Administration; Cooperative Institute for Research in Environmental Sciences; National Park Service; Regional Air Quality Council; Global Ozone Project; Western Regional Air Partnership; Environmental Protection Agency; University of Colorado Boulder; Colorado State University; University of California, Berkeley; University of Wisconsin; University of Cincinnati; Georgia Institute of Technology; University of California, Riverside; Aerodyne Inc.; U.S. Naval Academy; University of Rhode Island; University of California, Irvine; and Princeton University.

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Fast climbing mercury to top out in mid to upper 90s Monday

Monday, July 21st, 2014 5:49am MDT

A hot Monday and week ahead are going to make last week’s wet and cool weather nothing but a memory very quickly.  Above normal temperatures are expected to remain with us until at least this weekend.

For today we are starting out the morning quite mild and will see the temperature climb quickly.  By noon we will have already eclipsed the 90 degree mark and be well on our way to a high pushing 99 degrees.  Afternoon cloud cover may inhibit that high temperature a bit much like it did yesterday.

Thunderstorm activity today is expected to remain to the south along the foothills and Palmer Divide but there is just a slight chance something pops up near Thornton.

See the image for today’s outlook and keep an eye on the thermometer here: http://www.thorntonweather.com/live-weather-2.php

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The heat is on: Temperatures to climb Sunday, stay hot for most of the week ahead

Sunday, July 20th, 2014 6:57am MDT

Temperatures climb today as Thornton looks for a high around 98 degrees.  The week ahead will be largely dominated by warmer than normal temperatures.  It could be Saturday before we cool down (and only a bit).

Extended forecast: http://www.thorntonweather.com/forecast.php

(Image courtesy the National Weather Service).

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July 13 to July 19: This Week in Denver Weather History

Saturday, July 19th, 2014 6:00pm MDT
This Week In Denver Weather History

July 13 to July 19: This Week in Denver Weather History

Snow in July? Officially no however, it was on July 17, 1872 that a U.S. Army Signal Service weather observer reported snow in Denver. However since official record-keeping did not begin until 1882, it doesn’t count. Read more about that event and others from this week in Denver weather history below.

From the National Weather Service:


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


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 1902…west winds were sustained to 42 mph with gusts to 48 mph.

In 1910…an apparent dry microburst produced northeast winds sustained to 41 mph.

In 1961…hail as large as 1 inch in diameter was reported near Commerce City.

In 1982…a tornado touched down briefly south of Parker. No damage was reported.

In 1985…thunderstorms drenched the Highlands Ranch area of northern Douglas County with 1.50 inches of rain in just 30 minutes. Half an inch of rain fell in 15 minutes in Littleton.

In 1986…a lightning bolt struck a church steeple in Littleton…toppling it to the ground.

In 1989…thunderstorm winds blew down trees and bent a metal basketball fixture just north of Castle Rock in the surrey ridge area.

In 1993…1 inch diameter hail was measured in Lakewood.

In 1995…lightning struck and injured an assistant coach during a baseball game at Highlands Ranch south of Denver.

In 1996…3/4 inch diameter hail fell in Lochbuie with 1 1/2 inch hail measured in Brighton. Thunderstorm winds gusted to 69 mph at Bennett. The strong winds were responsible for flipping three semi-trailer trucks onto their sides along I-70…3 miles east of Bennett. A few cars were also overturned.

In 2001…heavy thunderstorm rain caused flash flooding over south metro Denver. Three inches of rain reportedly fell near the greenwood village police department in the span of 15 minutes. The heavy rain caused toll gate creek to overflow…flooding low lying areas along Parker road. Heavy rainfall also caused local flooding along streets near the Denver technology center. A severe thunderstorm dumped hail to 1 3/4 inches in diameter near Castle Rock.

In 2003…maximum temperature of 100 degrees was a record high for the date.

In 2009…severe thunderstorms produced wind gusts to 70 mph near Parker and Strasburg. At Denver International Airport…west-northwest winds gusted to 40 mph.

In 2011…severe thunderstorms produced extensive damage as they moved across the urban corridor. At Denver International Airport alone…large hail up to golfball size…very heavy rain and wind gusts to 59 mph caused substantial damage to 40 planes and stranded approximately 1500 passengers overnight. Frontier and United airlines were hardest hit as dozens of planes were taken out of service for repairs; forcing the cancellation of at least 220 flights over the next several days. Damage to the aircrafts alone was nearly five million dollars. In addition…83 cars in airport parking lots were damaged… Along with some police cars and maintenance vehicles. In Watkins…two people suffered minor injuries and 35 to 40 homes were damaged. As many as two hundred residents in a mobile home park were left homeless by the storm…forcing the red cross to open a shelter at Bennett high school. The trailer park contained 52 mobile homes…14 recreational vehicles…3 houses and a commercial building. Hailstones the size of softballs cratered the north sides of the mobile homes. Some farmers in the area said they lost as much as 85 percent of their total wheat crop. Power lines were also damaged which affected about 1200 customers in Watkins. The strong winds also flipped over a tractor- trailer rig on I-70 near Watkins Road. Insurance claims for the Watkins…Bennett and Brighton areas was estimated to be seventeen million dollars. The total damage estimate across the entire urban corridor…was near one hundred sixty five million dollars…and included 17200 automobile claims and 12600 homeowner claims. In addition…thunderstorms producing very heavy rainfall…caused flash flooding in the Four Mile Canyon burn scar west of Boulder. Three homes reportedly had water up to the windows with water flowing into structures at Fourmile Canyon road and gold run road. The heavy rain caused a 4-ft surge along Fourmile Creek through Orodell and into the entry of Boulder Creek. Several roads were affected which restricted access to the area. Roads were closed due to water and debris. Private bridges and drives were washed out and several residents were stranded and later rescued. Numerous cars were damaged in debris flows and several structures suffered flood damage but were not destroyed.


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 1878…the temperature reached a high of 100 degrees in downtown Denver.

In 1906…a thunderstorm produced north winds sustained to 52 mph and 0.53 inch of rain in 10 minutes.

In 1912…a heavy thunderstorm cloudburst in the late afternoon combined with a similar storm to the south of the city to produce widespread flooding on Cherry Creek in downtown Denver…which resulted in two deaths and several injuries. The flooding was the worst since 1864 and covered around 3 square miles of lower downtown. Bridges along Cherry Creek were washed out and water lapped at the floor of the Broadway bridge over the South Platte River…causing authorities to declare it unsafe except for pedestrians. By nightfall… Union Depot was under 2 to 3 feet of water…and railroad and street car traffic was stalled. Those forced from their homes by the surging flood waters took refuge in the Denver auditorium. The flood waters caused great damage to the sewerage system…parkways…bridges and residences and commercial warehouses near Cherry Creek in the wholesale district. Flood damage was estimated at several million dollars. Heavy thunderstorm rainfall of 2.00 inches…of which nearly 1.75 inch fell in 30 minutes in central Denver… Was accompanied by severe thunderstorm winds sustained to 55 mph with gusts as high as 74 mph.

In 1933…thunderstorm rainfall was only 0.01 inch…but northwest winds sustained to 37 mph with gusts to 47 mph produced a dust storm for about 10 minutes during the late afternoon.

In 1967…heavy rain flooded areas of north and west metro Denver…and high water closed street intersections in the city. Crops were damaged…and 200 chickens drowned by flooding northwest of Denver where farm buildings and irrigation facilities were also damaged.

In 1969…a thunderstorm wind gust to 51 mph was recorded at Stapleton International Airport.

In 1975…heavy rains caused locally heavy flash flooding along Niver Creek south of Thornton and in other parts of north metro Denver. Over 40 thousand dollars in damage to public property was reported…and numerous homes and yards were damaged.

In 1986…thunderstorm winds blew down a power line in west- central Jefferson County. The storm…as it moved into Denver…snapped tree limbs and damaged a fence near Washington Park. Wind gusts in the area were estimated at 80 to 85 mph.

In 1990…thunderstorm wind gusts to 58 mph were recorded at Buckley Field in Aurora. No damage was reported. Winds gusted to 44 mph at Stapleton International Airport.

In 1993…a severe thunderstorm moved across southern sections of metro Denver. Dime size hail fell in Lakewood…and hail up to one inch diameter was measured at Cheery Creek Reservoir. Later in the afternoon…hail to one inch diameter fell in Golden and Arvada.

In 1994…hail to 1 1/4 inches in diameter fell north of Bennett.

In 1998…dry microburst winds estimated to 70 mph snapped tree branches up to 4 inches in diameter in Brighton where some road signs were twisted and blown down. At Denver International Airport…dry microburst winds gusted to 61 mph.

In 1995…thunderstorm winds gusted to 62 mph near Strasburg.

In 2001…a severe thunderstorm dumped hail to 3/4 inch in diameter in the foothills about 10 miles northwest of Golden.

In 2011…severe thunderstorms in the Denver metropolitan area produced very heavy rain…large hail and damaging winds. The strong winds toppled a few trees and the heavy rain caused street flooding and minor flash flooding. Several cars were stranded at the intersection of Santa Fe Drive and Oxford…and near Broadway and U.S. Highway 285. A 16-yr old teenager was seriously injured when he tried to retrieve a ball along the banks of West Toll Gate Creek. He was pulled from the swollen creek and died several days later. Hail up to one inch in diameter was reported around the area. The thunderstorms also produced frequent lightning. One strike sparked a fire at aspen academy…a private school in Greenwood Village. Most of the damage was confined to the roof and attic. In Englewood…a 40-ft tree was blown into a house and knocked down some power lines. At Denver International Airport…a severe thunderstorm produced sustained winds of 47 mph and a peak wind gust to 68 mph.


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.

» Click here to read the rest of July 13 to July 19: This Week in Denver Weather History

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