All posts by Thornton Weather

ThorntonWeather.com is your local source for live Thornton, Colorado weather conditions and news!
Weather History

July 9 to July 15: This week in Denver weather history

Leave a comment
This Week In Denver Weather History
July 9 to July 15: This Week in Denver Weather History

Our look back at this week in Denver weather history demonstrates why July is considered the Mile High City’s stormiest month. Many instances of flooding rains, damaging wind and hail and dangerous lightning are seen in our past.

From the National Weather Service:

1-18

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.

1-31

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.

6-23

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.

7-25

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.

9

In 1872…a very brisk wind between 2:00 pm and 3:00 pm spread a cloud of dust and sand into the city.

In 1874…northeast winds at sustained speeds up to 36 mph blew immense clouds of dust from the prairie through the streets of the city around mid-morning. The houses across the street from the weather station were not visible at the peak of the storm.

In 1875…heavy thunderstorm rains caused stream flooding… Which damaged nearly all railroads into the city. Rainfall in the city was only 0.14 inch.

In 1953…heavy thunderstorm rains caused an estimated 2 million dollars damage from flooded stores and basements across metro Denver. The flood waters reached a depth of 3 feet on streets in some sections of the city…damaging streets and automobiles. The heavy rainfall at Lowry Air Force Base totaled 3.90 inches. At Stapleton Airport where the heavy rain briefly reduced the surface visibility to 1/2 mile…only 1.05 inches of rain were measured. North winds gusting to 52 mph caused some damage in east Denver.

In 1982…two small tornadoes were spotted east of Rocky Flats… And a tornado touched down briefly 5 miles east of Brighton. No damage was reported.

In 1984…heavy rain fell over southern sections of metro Denver. Rainfall totaled 1.50 inches in just 15 minutes between Littleton and Sedalia.

In 1987…a thunderstorm microburst produced a wind gust of 58 mph at Erie north of Denver.

In 1988…hail to 3/4 inch in diameter piled up 2 to 4 inches deep in Idaho Springs. Some basements were flooded and several thousand gallons of fuel were contaminated when water flooded a gasoline storage tank. A tornado sighted near Manilla 5 miles west of Bennett remained on the ground for 9 minutes. No damage was reported.

In 1990…a severe thunderstorm produced a tornado and heavy rain over northeast metro Denver. As much as 4 inches of rain fell in just 20 minutes in Commerce City…causing the South Platte River to rise quickly and flood lowland areas. The raging flood waters caused extensive damage to a 30-foot stretch of railroad track embankment…destroyed a railroad trestle and a nearby garage…and washed away a vintage 1960’s show car near East 58th Avenue and York Street. The car was found a couple of miles downstream in a pool of deep mud and murky water. Rainfall totaled 1.34 inches at Stapleton International Airport where 1/2 inch diameter hail fell. The same thunderstorm produced a brief tornado in a vacant field near 64th Avenue and Tower Road just east of the Rocky Mountain Arsenal. No damage was reported from the twister. Lightning from the storm caused power outages to as many as 7 thousand homes and businesses.

In 1996…a tornado (F0) was reported 5 miles south of Hudson. No damage was reported. Twin weak tornadoes (F0) formed for a short time near the northeast runways at Denver International Airport. Less than 15 minutes later…a weak tornado (F0) touched down in the employee parking lot at DIA. Several car windows were blown out…and a few vehicles sustained minor body damage from flying debris. Several signs were also blown down. Later…twin weak tornadoes (F0) touched down again in open country between DIA and Watkins.

In 2004…severe thunderstorms produced hail to 3/4 inch in diameter near tiny town and wind gusts to 66 mph in Bennett. A thunderstorm wind gust to 56 mph was measured at Denver International Airport.

In 2005…a thunderstorm produced a wind gust to 54 mph at Denver International Airport.

9-10

In 1980…a series of severe thunderstorms hit metro Denver… Dumping heavy rain and producing a spectacular lightning display lasting for several hours. A number of homes were damaged by lightning. Winds gusted to 60 mph at Stapleton International Airport where about half an inch of rain fell in just 10 minutes along with 1/4 inch diameter hail. The evening thunderstorms continued into the early morning hours with total rainfall of 1.35 inches at Stapleton International Airport.

In 1998…thunderstorm rainfall totaled 2.04 inches at the site of the former Stapleton International Airport.

10

In 1878…a lunar rainbow was observed during a light mist and fog.

In 1895…the temperature warmed to a high of only 53 degrees… The all-time record lowest maximum temperature for the month of July.

In 1967…golf ball size hail damaged aircraft at Jefferson County Airport near Broomfield.

In 1983…two people were injured when struck by lightning just southwest of Morrison. A man was injured when he was swept downstream by a flash flood on a tributary of clear creek in the canyon 8 miles west of Golden. Heavy thunderstorm rains caused mudslides which closed several roads. Rainfall amounts included: 1.75 inches in 20 minutes in southeast Denver…1.26 inches in 35 minutes in Boulder…2.14 inches in 2 hours in Lakewood…1.70 inches in 45 minutes in Aurora…and 1.25 inches in 30 minutes atop Floyd Hill in the foothills west of Denver.

In 1992…storm spotters reported 3/4 inch diameter hail near the construction site of the new Denver airport just northeast of the city.

In 1995…microburst winds toppled a pine tree 60 feet high and 2 feet in diameter in Denver. The tree fell and injured a man nearby. Microburst winds to 59 mph broke the glass on a door at the national weather service forecast office at the site of the former Stapleton International Airport.

In 1998…thunderstorm rainfall totaled 2.35 inches at Denver International Airport.

In 2000…three children were injured…one critically…when lightning hit a nearby tree at panorama point atop Flagstaff Mountain just west of Boulder. Lightning hit the tree…entered the ground…then struck the children. Lightning sparked a grassfire that burned about 50 acres at the Rocky Flats Environmental Test Facility. Also… Lightning sparked at least 6 fires in the Hudson and Keenesburg areas as thunderstorms…accompanied with heavy rain…large hail…and tornadoes…moved through southern Weld County. Over 2 inches of very heavy rain caused flooding along an I-76 exit ramp near Keenesburg. The fire department rescued 15 stranded motorists as high water inundated sections of the exit ramp and adjacent highway. Basements were also flooded in Keenesburg. One home reportedly had 7 feet of standing water in the basement before the rain subsided. A weak tornado (F0) touched down briefly near Brighton…but caused no damage.

In 2001…a severe thunderstorm dumped 7/8 inch diameter hail in wheat ridge.

In 2002…severe thunderstorms pelted the southern suburbs of metro Denver with large hail. Hail as large as 3 inches in diameter fell 6 miles southeast of Parker. Other large hail reports included 2 inch diameter hail around centennial airport and 3/4 inch hail near Sedalia and Deckers. Hail as large as 3/4 inch was also reported in Broomfield. Runoff from heavy thunderstorm rainfall in the Hayman fire burn area flooded lost creek ranch with up to 18 inches of water just off State Highway 126. Floodwaters damaged a very expensive rug in the lodge. A driveway to a residence was washed away. In Douglas County…runoff damaged forest access roads in the Turkey Creek drainage.

In 2011…a severe thunderstorm produced intense microburst winds in southeast Boulder County. A peak wind gust to 75 mph was recorded in Superior with gust to 58 mph…2 miles south of Lafayette. At Denver International Airport…a peak wind gust of 31 mph was recorded.

11

In 1872…heavy rainfall started at 4:00 pm and continued into the night. The heavy rainfall damaged homes and buildings in all parts of the city. Rainfall totaled 1.64 inches.

In 1888…the temperature reached 100 degrees in downtown Denver.

In 1954…the high temperature climbed to 102 degrees at Stapleton Airport.

In 1970…a girl walking in a park in southeast Denver received eye and facial injuries when lightning struck nearby. Lightning also caused numerous power outages and heavy rainfall produced local flooding at several locations across metro Denver.

In 1974…large hail up to 1 1/2 inches in diameter fell in Thornton.

In 1990…the worst hailstorm in American history in terms of dollar damage at the time battered metro Denver. Storm damage totaled 605 million dollars…as it cut a 5-to 10-mile wide swath from just southeast of Estes Park to northeast of Colorado Springs. Hail as large as baseballs (2.75 inches) pounded metro Denver. Hardest hit areas were southeast Boulder County…the Jefferson County Airport in Broomfield… Arvada…east Wheat Ridge…southwest and south-central Westminster…west Thornton…northwest…west-central and downtown Denver…northeast and east-central Lakewood…just east of Littleton…portions of Arapahoe County west of I-25… And northern and central Douglas County near Castle Rock and Franktown. Golf ball to baseball size hail severely damaged roofs on thousands of homes and buildings…battered tens of thousands of automobiles…windows…signs…street lights…and traffic signals…stripped paint…awnings…and trim from buildings…punched holes in the roofs of two homes in Arvada…knocked out power and telephone service to thousands of homes and businesses…defoliated thousands of trees…ripped up greens and fairways on a number of golf courses…and severely damaged several aircraft tied down at Jefferson County Airport. Hail the size of baseballs fell for several minutes in old town Arvada. Later…golf ball size hail and heavy rain pummeled two northwest Denver amusement parks. Hardest hit was Elitch Gardens Amusement Park where 47 people were injured and received treatment for bumps…cuts…and bruises at local hospitals. Many of the injured were stranded on rides during the storm when power failed. Hail clogged storm sewers…causing rain water to back up 3 to 6 feet deep on some roads and intersections in Arvada. Several basements were flooded. In some places hail was washed into drifts several feet deep. In addition… The storm spawned 2 small tornadoes. One touched down briefly in Lakewood near 6th avenue and Kipling Blvd….but did no damage. In Castle Rock…a tornado (F1) did heavy damage to some homes and vehicles in the Founders Village development near Ridge Road.

In 2001…lightning struck two homes in Thornton. Most of the damage was confined to the attics of both homes. Hail as large as 3/4 inch in diameter fell in Keenesburg…Longmont… And near Boulder.

In 2011…severe thunderstorms developed over parts of Adams and Denver Counties. At Denver International Airport…a severe thunderstorm produced a peak wind gust to 66 mph…with another gust to 59 mph measured in Denver. In Commerce City…the intense winds blew down a large tree.

Continue reading July 9 to July 15: This week in Denver weather history →

Natural Disasters

5.8 Magnitude Earthquake Hits Montana

Leave a comment

Yellowstone National Park, which covers parts of Wyoming, Idaho and Montana, lies on top of a supervolcano that could effectively wipe out the United States if it were to explode. The last time it did, 640,000 years ago, it expelled 240 cubic miles (think about that) of rocky debris into the sky. Early Thursday morning, residents… Continue reading 5.8 Magnitude Earthquake Hits Montana →
Climatology, Thornton Weather

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

Leave a comment

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:

CLIMATE REPORT
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
729 AM MDT SAT JUL 1 2017

...................................

...THE DENVER CO CLIMATE SUMMARY FOR THE MONTH OF JUNE 2017...

CLIMATE NORMAL PERIOD 1981 TO 2010
CLIMATE RECORD PERIOD 1872 TO 2017

WEATHER         OBSERVED          NORMAL  DEPART  LAST YEAR`S
                 VALUE   DATE(S)  VALUE   FROM    VALUE  DATE(S)
                                          NORMAL
................................................................
TEMPERATURE (F)
RECORD
 HIGH             105   06/26/2012
                        06/25/2012
  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 
PRECIPITATION (INCHES) 
RECORD
 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
GREATEST
 24 HR. TOTAL    0.13   06/29 TO 06/29           06/13 TO 06/13

SNOWFALL (INCHES)
RECORD            0.5 1953
 TOTAL            0.0 2017          0.0

DEGREE_DAYS
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

FREEZE DATES
RECORD
 EARLIEST     09/08/1962
 LATEST       06/08/2007
EARLIEST      04/01             10/07
LATEST        05/04             05/05
....................................................

WIND (MPH)
AVERAGE WIND SPEED              10.1
RESULTANT WIND SPEED/DIRECTION   2/135
HIGHEST WIND SPEED/DIRECTION    44/270    DATE  06/27
HIGHEST GUST SPEED/DIRECTION    66/270    DATE  06/27

SKY COVER
POSSIBLE SUNSHINE (PERCENT)   MM
AVERAGE SKY COVER           0.50
NUMBER OF DAYS FAIR            6
NUMBER OF DAYS PC             22
NUMBER OF DAYS CLOUDY          2

AVERAGE RH (PERCENT)     47

WEATHER CONDITIONS. NUMBER OF DAYS WITH
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

-  INDICATES NEGATIVE NUMBERS.
R  INDICATES RECORD WAS SET OR TIED.
MM INDICATES DATA IS MISSING.
T  INDICATES TRACE AMOUNT.
Astronomy

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

Leave a comment

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,… Continue reading Pence Vows: ‘American Boots on the Face of Mars’ →
Weather History

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

Leave a comment
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:

29-2

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.

29-15

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.

1-18

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.

1-31

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.

2

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.

3

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 Continue reading July 2 to July 8: This week in Denver weather history →

Climatology

July weather preview: Hot temps, storms typically the highlight

Leave a comment

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.

Natural Disasters

As wildfires rage in West, DC lawmakers fight over forest policy

Leave a comment

WASHINGTON — With wildfire season raging in western states, Congress is embroiled in a battle over how best to fight the fires. Many Republicans want to help prevent and fight wildfires by giving the agencies that manage the federal forests more money and greater ability to thin out the forests. Most Democrats, as well as environmental… Continue reading As wildfires rage in West, DC lawmakers fight over forest policy →
Weather History

June 25 to July 1: This week in Denver weather history

Leave a comment
This Week In Denver Weather History
June 25 to July 1: This Week in Denver Weather History

Our look back at this week in Denver weather history certainly has plenty of the usual suspects related to severe weather. Most notable however are the many occurrences of lightning strikes and the effects they can have from sparking fires to causing significant injury and death.

From the National Weather Service:

22-26

In 2012…the maximum temperature exceeded 100 degrees for five consecutive days. Two of the high temperatures on the 25th and 26th peaked at 105 degrees…which set the all time record for the month of June and tied the all time maximum temperature for Denver.

25

In 1873…forest fires produced a great deal of smoke in the mountains to the southwest of the city.

In 1958…an unusually cold day for summer set two temperature records for the date. Under cloudy skies with occasional drizzle…a record low maximum temperature of 55 degrees was established along with a record minimum temperature of 42 degrees.

In 1959…a waitress…working at a kitchen sink… Was injured by a bolt of lightning…which struck the rear of a tavern in Denver. She was hospitalized.

In 1971…a tornado touched down briefly at a high school football field in Brighton…but caused no damage.

In 1981…3/4 inch hail pelted Wheat Ridge and hail to 1 1/4 inches fell in Louisville. A brief funnel cloud was sighted by national weather service personnel 4 miles east of Stapleton International Airport.

In 1982…a bolt of lightning struck a cabin in the foothills west of Denver. The resulting fire totally destroyed the cabin.

In 1987…golf ball size hail fell near Bennett.

In 1988…a tornado touched down 1 mile south of Watkins and was on the ground for 4 minutes. Another tornado was spotted just southeast of Barr Lake and was on the ground for 5 minutes. No damage was reported from either tornado. Lightning struck two rock climbers near Eldorado Springs. A 25-year-old man was killed…and a 21-year-old man suffered extensive injuries. Thunderstorm winds knocked over two elm trees near downtown Denver. One fell on a house destroying most of it. A nearby building was unroofed…and two cars were damaged. A truck that had been severely damaged by one of the Denver tornadoes 10 days before was hit again. Thunderstorm wind gusts to 51 mph were recorded at Stapleton International Airport.

In 1991…the temperature reached a high of 100 degrees… Setting a new record for the date.

In 1997…one inch diameter hail fell in Arvada and 1 1/2 inch hail in Boulder. Hail as large as 3/4 inches fell in Denver…Louisville…Westminster… And near Broomfield.

In 1999…thunderstorm winds gusted to 58 mph near Fort Lupton toppling an oil rig. A 37-year-old man was killed when he fell 55 feet from the derrick of the rig.

In 2001…four golfers and one construction worker received minor injuries from a nearby lightning strike on the Broadlands Golf Course in Broomfield.

In 2002…hail to 1 inch in diameter was measured in greenwood village.

In 2005…hail to 3/4 inch in diameter fell near Bennett and Roggen. A thunderstorm wind gust to 61 mph was recorded near Golden.

In 2009…lightning struck the Darlington Prismatic Electric Fountain in City Park`s lake. The damage was estimated to be approximately $25000.

In 2010…wind gusts associated with a dry microburst downed several trees in the vicinity of 14th and federal…and near Bayaud St. and Clarkson St. in Denver. At Denver International Airport…a peak wind gust to 45 mph was observed from the southwest.

25-26

In 1969…high winds raked Boulder causing one fatality and some injuries. One man was injured by a falling tree limb. At the National Center for Atmospheric Research in Boulder… Sustained winds of 55 to 60 mph with wind gusts to 123 mph were recorded. In downtown Boulder…winds averaged 30 to 40 mph with gusts to 70 mph. Widespread minor damage occurred… Especially in the Table Mesa area of south Boulder. Much tree damage occurred in the older areas of Boulder where several trees were uprooted. A mobile home was overturned by the winds. At Stapleton Airport…west winds gusted to 43 mph on the 25th and 37 mph on the 26th.

In 1975…strong winds damaged utility lines…buildings… Vehicles…trees… And power lines in Boulder and other communities to the north of Boulder. Microburst winds gusted to 45 mph at Stapleton International Airport on the 25th.

In 1983…heavy rain fell in the foothills west of Denver with 1.50 inches in 30 minutes at Intercanyon. Heavy rain continued over metro Denver on the 26th with two-day storm totals at many locations ranging from 1.00 to 2.50 inches. Rainfall totaled 1.37 inches at Stapleton International Airport on the 26th.

In 1985…one to two inches of rain fell over metro Denver. At Stapleton International Airport…rainfall totaled 0.93 inches…thunderstorm winds gusted to 44 mph… And 7/10 inch hail was measured. The air mass was unusually cold for the season…and snow fell in the foothills above 8 thousand feet. The high temperature of only 63 degrees on the 26th equaled the record low maximum reading for the date.

 

26

In 1873…there was a great deal of smoke from a large forest fire in the mountains to the southwest of the city and a smaller fire directly to the west.

In 1874…fires at timberline to the west were visible from the city. New and extensive fires were continually started from south to northwest along the ridge line. Carelessness of tourists was the apparent cause of the fires. Large and valuable tracts of timber had already been destroyed.

In 1890…the only thunderstorm of the month produced a trace of rain. A trace of rain also fell on 7 other days. This was the only precipitation recorded during the month… Making it the driest June on record.

In 1893…northwest winds were sustained to 45 mph with gusts to 48 mph.

In 1971…a microburst wind gust to 58 mph was recorded at Stapleton International Airport. Dust devils were sighted.

In 1980…strong gusty thunderstorm winds damaged several mobile homes in Thornton. Thunderstorm winds gusted to 37 mph at Stapleton International Airport.

In 1986…hail piled up 1 1/2 inches deep in Golden Gate Canyon and covered roadways an inch deep in Evergreen.

In 1988…a tornado touched down 2 miles north of Watkins. It was on the ground for 15 minutes and did no reported damage.

In 1989…two inch diameter hail fell at Kassler…1 inch hail at Louviers…and 1 1/2 inch hail at tiny town.

In 1991…high winds…not associated with thunderstorms… Damaged a home in the Green Mountain area. The strong winds picked up a heavy metal and glass table on the deck of a house and threw it into the house. The table was destroyed and the house received considerable damage.

In 1992…3/4 inch diameter hail fell in south Aurora and near Buckley Air National Guard base. Golf ball size hail was reported in Parker.

In 1994…the all-time highest recorded temperature in June and the second highest temperature ever recorded in Denver… 104 degrees occurred. This was the hottest day in Denver since August 8…1878…when the temperature reached 105 degrees.

In 2005…strong thunderstorm winds gusting to 58 mph damaged a garage and some nearby trees near Fort Lupton. Winds also gusted to 58 mph near Watkins. Thunderstorm winds gusted to 60 mph near Roggen. Hail to 3/4 inch in diameter was measured in southwest Aurora.

In 2009…severe thunderstorms moving through Denver and the surrounding metro area produced intense thunderstorm winds. At Denver International Airport…a wind gust blew a luggage car into a southwest airlines airplane causing some damage. Peak wind gusts included: 68 mph at Denver International Airport…4 miles west of rocky mountain metropolitan airport and 12.5 miles north of Lowry AFB; 64 mph near Arvada and Parker; and 60 mph in Aurora/cherry.

26-27

In 1965…wind gusts to 38 mph were recorded in downtown Boulder…causing widespread minor damage. A microburst wind gust to 41 mph was recorded at Stapleton International Airport.

27

In 1873…Pikes Peak was hidden from view by smoke from forest fires in the mountains to the southwest of the city.

In 1927…the temperature cooled to a low of only 72 degrees… The all-time record high minimum for the month.

In 1980…lightning injured 4 people on a baseball diamond in Broomfield. The bolt seriously injured the pitcher while also striking (out) the batter…catcher and second baseman.

In 1987…a microburst wind gust to 53 mph was recorded at Stapleton International Airport.

In 1990…the temperature reached a high of 102 degrees… Setting a new record maximum for the date.

In 1993…thunderstorm winds gusted to 60 mph across parts of metro Denver. A wind gust to 50 mph blew over a 30-foot canvas tent at an amusement park southeast of Denver. Fifteen people…mostly children…were injured. Microburst wind gusts to 33 mph were recorded at Stapleton International Airport.

In 2002…heavy rain…up to 3/4 inch…fell across sections of the Hayman burn area near Cheeseman Reservoir. Several forest service roads were washed out and many culverts were plugged by debris.

In 2004…heavy rain producing thunderstorms caused rock and mud slides across the overland fire burn area in Jamestown. An estimated 50 tons of sand…dirt…rock…and ash slid into town…filling a culvert under main street. The slide covered 150 to 225 feet of main street. The flood was produced by half an inch of rain in 30 minutes. A deluge of very heavy rainfall from nearly stationary thunderstorms caused flooding and flash flooding problems over parts of Jefferson and Douglas counties. An automated rain gage in Golden measured 3.60 inches of rainfall in one hour. Numerous homes were flooded in Golden…including one that was 146 years old. The home was listed as a complete loss. State Highway 93 had to be closed from the Pine Ridge subdivision to the Golden Gate Canyon Road. At the height of the storm…about 4 feet of water covered State Highway 93 through Golden… Forcing its temporary closure. Several intersections were also flooded and impassable. Rock and mud slides were reported in Golden Gate Canyon state park. At the Deer Creek Golf Course at Colorado 470 and Kipling…the greens were completely inundated by floodwaters. Some backyards near the golf course were partially washed out. In Douglas County…water up to a foot deep covered the roadways in Roxborough State Park. The Waterton Canyon Road also had to be closed due to high water.

In 2010…a severe thunderstorm produced hail up to 1 inch in diameter near Strasburg. Hail up to 3/4 inch in diameter was reported in Aurora and Buckley Air Field.

Continue reading June 25 to July 1: This week in Denver weather history →

Natural Disasters

Over 800 Earthquakes Recorded at Yellowstone Volcano

Leave a comment

Over 800 earthquakes have now been recorded at Yellowstone supervolcano over the last two weeks, with the ongoing swarm taking place on the western edge of the National Park. But there is virtually no risk of the volcano erupting, the United States Geological Survey (USGS) currently lists the volcano alert level as normal and the aviation… Continue reading Over 800 Earthquakes Recorded at Yellowstone Volcano →
Climatology

Record high temperature set for June 20

Leave a comment

Record High TemperaturesWe knew it would be hot today and the proof is in the numbers as Denver set a new record high temperature for the date.

According to the National Weather Service, the mercury topped out at 99 degrees at Denver International Airport.  This breaks the previous record high for June 20 of 97 degrees set in 2007.

Here in Thornton, we almost matched the record with a high of 97.9 degrees at 3:57pm.

There will be no break from the heat until Friday.

Tomorrow’s forecast high of 98 degrees mirrors today’s high and will again come close to the record for June 21 (99 degrees in 2007). Thursday does cool some but with a forecast high of 91 degrees, the reading will still be well above normal for the date (85 degrees).

  • Stay up to date with Thornton’s weather: Be sure to ‘like’ us on Facebook, follow us on Twitter and add us to your Google+ circles.