The month of May started off cool and damp but that did not last long. It soon dried out and warmed up leading to one of the warmest Mays on record.
The first three days of the month brought cool temperatures and generous amounts of rain, more than one inch total. We then followed that up with a warming trend that for a week.
Temperatures then cooled for the 12th and 13th of the month then started their upward trend again. Another, short break from the warmth came along from the 18th to the 20th.
After that, the warm weather returned and the last eleven days of the month all saw above normal mercury readings.
While there were a few days with rain after the wet start, none really amounted to much.
Thornton’s average temperature for the month came in at 60.5 degrees. By comparison, Denver’s long term average temperature for May is 57.1 degrees. Out at the airport where Denver’s official readings are taken, the month’s average temperature was warmer than ours at 61.4 degrees. That made the month the eight warmest May in Denver history.
Thornton saw its warmest temperature reading for the month of 92.4 degrees on the 26th of the month. The lowest reading of 35.4 degrees fell on the 4th. Denver saw its warmest reading of 94 degrees on the same day we saw our warmest and its coldest of 40 degrees on the 20th.
Denver set a record high temperature on the 10th and tied the record high temperature for the 25th. Additionally, the Mile High City saw four days with high temperatures at or above the 90 degree mark (Thornton had three). This breaks the record for the number of 90 degree days in May which previously was three days set in 1989 and 1874.
In terms of precipitation, Denver averages 2.12 inches during May. Thornton fell well short with 1.59 inches in our bucket. The Mile High City fared better, but still below normal, with 1.86 inches.
No snow fell during the month in Thornton or Denver.
CLIMATE REPORT
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
942 AM MDT FRI JUN 1 2018
...................................
...THE DENVER CO CLIMATE SUMMARY FOR THE MONTH OF MAY 2018...
CLIMATE NORMAL PERIOD 1981 TO 2010
CLIMATE RECORD PERIOD 1872 TO 2018
WEATHER OBSERVED NORMAL DEPART LAST YEAR`S
VALUE DATE(S) VALUE FROM VALUE DATE(S)
NORMAL
................................................................
TEMPERATURE (F)
RECORD
HIGH 95 05/26/1942
LOW 19 05/02/2013
05/03/1907
HIGHEST 94 05/26 86 05/06
LOWEST 40 05/20 32 05/04
05/03
05/02
AVG. MAXIMUM 75.4 71.5 3.9 69.6
AVG. MINIMUM 47.5 42.7 4.8 42.3
MEAN 61.4 57.1 4.3 55.9
DAYS MAX >= 90 4 0.8 3.2 0
DAYS MAX <= 32 0 0.0 0.0 0
DAYS MIN <= 32 0 1.9 -1.9 1
DAYS MIN <= 0 0 0.0 0.0 0
PRECIPITATION (INCHES)
RECORD
MAXIMUM 8.57 1876
MINIMUM 0.06 1974
TOTALS 1.86 2.12 -0.26 3.66
DAILY AVG. 0.06 0.07 -0.01 0.12
DAYS >= .01 8 9.4 -1.4 17
DAYS >= .10 5 4.8 0.2 11
DAYS >= .50 0 1.2 -1.2 2
DAYS >= 1.00 0 0.2 -0.2 1
GREATEST
24 HR. TOTAL 0.49 05/03 TO 05/03 05/18 TO 05/18
SNOWFALL (INCHES)
TOTALS 0.0 1.1
DEGREE_DAYS
HEATING TOTAL 151 265 -114 281
SINCE 7/1 5401 5996 -595 5084
COOLING TOTAL 46 21 25 6
SINCE 1/1 48 22 26 6
FREEZE DATES
RECORD
EARLIEST 09/08/1962
LATEST 06/08/2007
EARLIEST 10/07
LATEST 05/05
.................................................................
WIND (MPH)
AVERAGE WIND SPEED 9.9
RESULTANT WIND SPEED/DIRECTION 1/116
HIGHEST WIND SPEED/DIRECTION 36/330 DATE 05/30
HIGHEST GUST SPEED/DIRECTION 52/330 DATE 05/30
SKY COVER
POSSIBLE SUNSHINE (PERCENT) MM
AVERAGE SKY COVER 0.60
NUMBER OF DAYS FAIR 6
NUMBER OF DAYS PC 15
NUMBER OF DAYS CLOUDY 10
AVERAGE RH (PERCENT) 57
WEATHER CONDITIONS. NUMBER OF DAYS WITH
THUNDERSTORMS 11 MIXED PRECIP 3
HEAVY RAIN 2 RAIN 2
LIGHT RAIN 11 FREEZING RAIN 0
LT FREEZING RAIN 0 HAIL 3
HEAVY SNOW 0 SNOW 0
LIGHT SNOW 0 FOG W/VIS <=1/4 MILE 6
FOG 10 HAZE 3
- INDICATES NEGATIVE NUMBERS.
R INDICATES RECORD WAS SET OR TIED.
MM INDICATES DATA IS MISSING.
T INDICATES TRACE AMOUNT.
The evening of June 5 had been relatively calm after a record-tying high temperature. Some high-based thunderstorms then began to move through and created gusty winds. For some residents, those winds turned damaging.
What appears to have been a microburst (or multiple microbursts), brought fences, broke tree branches and for one Thornton family, toppled a 40 year old tree. Watch the video below for the story from CBS4.
The winds did appear confined to relatively small areas, hitting hard when they did. At ThorntonWeather.com, we saw some gusty winds (39mph) but nothing that would cause the type of damage seen by others.
The National Weather Service did report a 54mph gust at Denver International Airport and a 66mph gust at Buckley Air National Guard Base.
Did you suffer damage? If you have pics, we’d love to see them!
The recent heat is much more like we would expect to see toward the middle of July. High pressure though keeps the cooler air at bay and today Denver tied the record high temperature for the date.
As measured at Denver International Airport, the Mile High City saw an official high of 95 degrees. That ties the record high last set in 1946.
Here in Thornton, we were actually warmer by a good measure, something that doesn’t happen often. We topped out at 98 degrees at 3:06pm.
We will see a little bit of a reprieve from the heat tomorrow as a cold front moves through. Highs Wednesday should be in the upper 80s. After that though, the heat returns with 90+ degrees forecasted each day through the weekend.
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Extreme weather can occur during in month in Colorado we well know. June however is when traditional spring severe weather arrives in the state oftentimes with hail, damaging wind and tornadoes.
Over 40 percent of the tornadoes that occur in Colorado happen during the month of June. Far more common are thunderstorms with hail and wind, each responsible for extensive damage each year.
While severe weather is common, so too are brilliantly sunny and mild days as we close out spring and enter summer. If you are looking for cold, it isn’t likely but it is possible as the Denver area has seen freezing temperatures and yes, even snow, during the month.
Colorado’s famously highly variable weather seems to showcase itself during the month of May when a variety of weather conditions can be seen. This provides a prime opportunity for photos of everything weather to flora to fauna.
The month of May can bring extremes. Snow is not entirely uncommon during the month but more common is severe weather, particularly in the latter half of the month. Thunderstorms become more frequent and their associated hazards – lightning, wind, hail and tornadoes – are usual visitors. Providing additional subjects for pictures are the emerging spring flowers and our abundant wildlife.
Slideshow updated May 31, 2018. 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.
[flickr_set id=”72157696052081744″]
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.
Mother Nature seems to have a grudge against the City of Thornton’s annual spring festival. With thunderstorms arriving tonight and heavy rain expected through Saturday, most of the events have been cancelled.
As we get further into spring the chances for severe weather increase greatly across northeastern Colorado and that is seen in our look back at this week in Denver weather history. We also note the dangers this weather presents as we see events where the weather injured and even killed Coloradans.
From the National Weather Service:
12-13
In 1907…the temperature warmed to a high of 73 degrees on the 12th…before a cold front produced a thunderstorm… Northeast winds sustained to 40 mph…and rain changing to light snow overnight. Snowfall totaled only 2 inches…but the high temperature on the 13th was only 39 degrees.
In 1961…a storm that covered metro Denver with rain and snow started as thunderstorms on the evening of the 12th. Hail to 1 1/2 inches in diameter was reported 10 miles northwest of Stapleton Airport. Rain continued overnight and changed to snow on the 13th. Snowfall totaled 6.4 inches and precipitation (rain and melted snow) 1.96 inches at Stapleton Airport where north winds gusted to 39 mph. The rain and heavy wet snow caused icing damage to utility lines. Heavy snow occurred in the foothills.
In 1982…a major storm dumped 1.50 to 3.50 inches of rain across northeast Colorado and deposited prodigious amounts of snow in the foothills. Coal Creek Canyon southwest of Boulder was buried under 46 inches of snow with 39 inches at Nederland. The heavy wet snow downed many power lines in the foothills. In Thornton…the roof of a school was damaged by water from the heavy rain. At Stapleton International Airport…1.49 inches of rain were measured over the two day period. The heavy rain ended a severe and prolonged drought.
In 2004…a winter storm produced heavy snow in excess of a foot in the foothills above 6 thousand feet while heavy rain fell across the city. The heaviest snow occurred in the high country of Boulder County. Storm total snowfall was 14.5 inches near Jamestown. Rainfall totaled 0.81 inch at Denver International Airport with 0.94 inch recorded at Denver Stapleton. A trace of snow was recorded at both locations. East winds gusted to 24 mph at Denver International Airport on the 12th.
13
In 1905…a thunderstorm produced hail during the late afternoon. Precipitation totaled 0.57 inch.
13-14
In 1912…heavy snowfall totaled 12.4 inches over the city. Most of the snow…9.9 inches…fell on the 13th…which was the greatest 24 hour snowfall in May at the time. This was the last snowfall of the season. The low temperature dipped to 27 degrees on the morning of the 14th.
In 1989…a spring storm brought heavy rain and snow to the foothills. Metro Denver was soaked with 1 to 2 inches of rain. Rainfall totaled 1.26 inches at Stapleton International Airport. In the foothills…Echo Lake received 20 inches of snow. A 30-ton Boulder slid onto I-70 east of the Eisenhower Tunnel…closing the freeway for 2 hours.
14
In 1910…a thunderstorm produced strong winds during the afternoon. Northwest winds were sustained to 42 mph.
In 1913…light moist snow and light hail fell during short intervals…although no thunder was heard. The trace of snowfall was the only snow of the month. Precipitation… Mostly rain…totaled 0.44 inch.
In 1984…a pilot reported a tornado 16 miles east of Stapleton International Airport. No damage was reported. A thunderstorm produced a 58 mph wind gust in Brighton. Thunderstorm winds gusted to 48 mph at Stapleton International Airport.
In 1989…lightning struck a home in Evergreen…setting it afire.
In 1992…strong thunderstorm winds of unknown velocity… Knocked over and damaged the infield tote board at Arapahoe Park Racetrack just southeast of Aurora. Damage was estimated at 200 thousand dollars. No injuries were reported. Lightning started two house fires…causing 35 hundred dollars in damage in Adams County just 9 miles north-northwest of Denver.
In 1994…a sudden wind gust…estimated at 40 mph…blew a portion of the roof off a shopping center in Lafayette. The roof also damaged two parked cars in an adjacent lot.
In 2001…a construction worker in Castle Rock received minor injuries when lightning struck close-by.
In 2002…a microburst wind gust to 53 mph was recorded at Denver International Airport.
In 2007…severe thunderstorms producing large hail…very heavy rain…and tornadoes impacted the urban corridor and adjacent plains. Heavy rain associated with a severe thunderstorm caused flooding along a small tributary draining into the South Platte River. The incident took place at 13th and Decatur St….near Invesco Field. The floodwaters inundated the bike trail adjacent to the creek. A woman with her child sought refuge under a bridge and became trapped by the high water. The woman slipped and the stroller containing the child was swept into the swift current. The child drowned. Rainfall totaled 0.42 inches at Denver International Airport. Elsewhere…golf ball hail was reported near Hudson. Hail…up to one inch in diameter…was observed in Boulder and Lyons. Thunderstorm wind gusts estimated to 70 mph were reported near Buckley Air Force Base…with a peak wind gust to 37 mph observed at Denver International Airport. A small tornado touched down near Ft. Lupton but did no damage.
14-15
In 1977…high winds up to 100 mph felled hundreds of trees in Gilpin County and caused extensive damage to telephone and power lines. Lumber and steel tanks were blown around in Boulder canyon. West winds gusted to 46 mph at Stapleton International Airport on the 15th.
14-18
In 1996…a period of unusually warm weather resulted in 4 record maximum temperatures in 5 days. The record high temperatures were 87 degrees on the 14th…89 degrees on the 15th…and 93 degrees on both the 16th and 18th. The temperature climbed to only 81 degrees on the 17th which was not a record.
15
In 1894…southwest winds were sustained to 38 mph with gusts to 50 mph.
In 1910…an apparent cold front produced sustained northeast winds to 48 mph.
In 1986…a thunderstorm dumped an inch of rain in an hour over the eastern part of Aurora. Total rainfall from the storm was 1.62 inches.
In 1989…a 47 year old man…a Lakewood police officer…was struck and injured by lightning. Small hail piled up 3 to 4 inches deep near Golden. There was reported street flooding from heavy thunderstorm rains over western metro Denver. Rainfall totaled 0.76 inch at Stapleton International Airport.
In 1990…a thunderstorm produced a wind gust to 69 mph at Jefferson County Airport in Broomfield. Thunderstorm winds gusting to 49 mph at Stapleton International Airport produced some blowing dust.
In 1991…a funnel cloud was sighted near Morrison. Later… Hail up to 2 inches deep covered U.S. Highway 285 at South Turkey Creek Road in west metro Denver. Baseball size hail was reported on the east side of Littleton. Dime size hail was reported in Boulder.
In 1993…lightning started a fire which damaged a home in Boulder. No one was injured.
In 1997…a wind gust to 58 mph was recorded at the site of the former Stapleton International Airport. A street sign was blown down at the Havana Street exit along I-70.
In 1999…lightning ignited a small fire in a 3-story structure in sunshine canyon above Boulder. The fire was quickly extinguished and caused only minor damage.
In 2003…thunderstorms produced very heavy rainfall and localized flash flooding in the foothills of central Boulder County. Rainfall ranged from 1.5 to 2.5 inches in less than 2 hours. Water ranging in depth from 6 to 9 inches covered State Highway 119 in Boulder Canyon. Dirt and rocks also washed over the roadway. Some basements were flooded in the sugarloaf area. Rockslides were also reported at Boulder falls…Lefthand Canyon…and Fourmile Canyon.
15-16
In 1957…heavy snowfall totaled 8.8 inches at Stapleton Airport. The greatest amount on the ground was 3 inches.
In 1986…a spring storm dumped 1 to 2 inches of rain over metro Denver…but 2.71 inches fell at Buckley Field in Aurora. Rainfall only totaled 0.84 inch at Stapleton International Airport. Snow fell in the foothills with 7 inches recorded in Coal Creek Canyon southwest of Boulder.
16
In 1875…a heavy hail storm turned into heavy rain during the afternoon. Rainfall totaled 0.86 inch in just 37 minutes…while the temperature dropped 22 degrees in 22 minutes. Precipitation totaled 0.90 inch.
In 1894…west winds were sustained to 48 mph with gusts to 56 mph.
In 1949…a tornado was observed for 16 minutes…20 miles to the southeast of Stapleton Airport. The tornado moved 5 miles to the northeast before dissipating. No damage was reported.
In 1963…intense lightning started several forest fires in the foothills southwest of Denver near Deckers and Cheeseman Lake. Little precipitation fell from the storms to alleviate the unusual dry conditions so early in the season.
In 1978…thunderstorm winds caused damage in southeast Aurora. Winds of 60 to 80 mph blew down numerous fences and damaged several homes under construction. High winds tore docks loose at Cheery Creek Reservoir…sinking 3 or 4 boats and damaging about 15 others. At Stapleton International Airport where winds gusted to 60 mph…a 727 jet suffered 15 hundred dollars damage when wind toppled a runway light onto it. The public reported an unconfirmed tornado 7 miles south-southwest of Stapleton International Airport.
In 1990…a line of thunderstorms moving across metro Denver uprooted a large ash tree…which fell and blocked the outside doors to a Denver elementary school…briefly trapping the students inside. Thunderstorm wind gusts to 69 mph were reported at Jefferson County Airport. Northwest winds gusted to 44 mph at Stapleton International Airport.
In 1991…two tornadoes touched down briefly in Castle Rock… But no injuries or damage were recorded. Heavy thunderstorm rains of 0.50 to 1.10 inches in a couple of hours caused Lena Gulch near Golden to flood. No damage was reported.
In 1996…dry microburst winds of unknown strength overturned a trailer and damaged storage sheds in Strasburg east of Denver.
It was almost certain today was going to bring record-setting temperatures for the date and sure enough, it did.
The old record high for May 10 was 86 degrees set in 1991 and years prior. The National Weather Service reports that at 3:51pm today the temperature hit 90 degrees, easily breaking the record.
Additionally, this is the fourth earliest in the season that Denver has seen a 90 degree mercury reading since record keeping began in the Mile High City in 1872.
Here in Thornton we managed to be just a little bit cooler with a high of 89 degrees at 3:34pm.
Tomorrow things cool down and the weather becomes a bit unsettled. Look for highs near 80 with a good chance of PM storms. Then, this weekend gets cooler and brings even better chances for precipitation.
The weather forecast for May 8, 2017 was relatively typical for this time of year with pleasant temperatures and a sunny morning. We also wrote about the usual chance for PM thunderstorms but cautioned they could be potent saying, “Strong winds, large hail and possibly an isolated tornado will be possible.”
Little did we know just how potent they would be.
The thunderstorms that rolled through the Denver metro area that day brought monstrous hail, destroying windows, roofs, siding and vehicles.
As expected, the worst of the storms stayed south of Thornton but the areas that were hit from Golden to just north of downtown Denver were devastated. The tally to date is $2.3 billion in damage.
Fox 31 did a special on the storm last year and it makes for an interesting look back – and a reminder of the power of Mother Nature.
The month of April was one that failed to bring much in the way of snow or rain. This exacerbated the growing drought conditions, despite the end of the month bring some relief.
The first third of the month did bring a few days with light snow but nothing that ever amounted to much. Temperatures overall were a bit warmer than normal during the period and many days featured breezy winds serving to help dry things out.
We then put together three unseasonably warm days from the 10th to the 12th. The 13th saw things cool down but the majority of the snow in the region stayed well east of Thornton.
Perhaps the most notable event of the month came on the 17th when a strong upper level system passed over us. This brought extremely strong winds and resulted in Thornton recording its strongest wind gust in the past 10 plus years (62.1 mph).
Finally on the 20th we started seeing some precipitation with two of the next five days seeing light snow and the others having some rain. The month wrapped up with four straight days of temperatures well above normal.
Thornton’s overall average temperature for the month came in at 48.3 degrees. This was nearly a full degree warmer than the long term Denver average temperature for the month of 47.4 degrees. Out at Denver International Airport where the Mile High City’s official measurements are taken, it was slightly cooler with an average reading of 47.8 degres.
Temperatures in Thornton ranged from a high of 83.6 degrees on the 29th down to our coldest reading of 22.1 degrees on the morning of the 6th and the 7th. Denver’s maximum and minimum were similar with 83 degrees on the 29th and 21 degrees on the 6th.
In terms of precipitation, Denver averages 1.71 inches of liquid precip during April Thornton saw only 1.07 inches while Denver was even drier with 0.86 inches.
Snowfall at both locations fell short of the April average of 6.8 inches. Thornton recorded 3.9 inches while Denver only saw 1.5 inches.
CLIMATE REPORT
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
1208 PM MDT WED MAY 2 2018
...................................
...THE DENVER CO CLIMATE SUMMARY FOR THE MONTH OF APRIL 2018...
CLIMATE NORMAL PERIOD 1981 TO 2010
CLIMATE RECORD PERIOD 1872 TO 2018
WEATHER OBSERVED NORMAL DEPART LAST YEAR`S
VALUE DATE(S) VALUE FROM VALUE DATE(S)
NORMAL
................................................................
TEMPERATURE (F)
RECORD
HIGH 90 04/30/1992
LOW -2 04/02/1975
HIGHEST 83 04/29 79 04/14
04/13
LOWEST 21 04/06 24 04/10
AVG. MAXIMUM 63.2 61.5 1.7 63.2
AVG. MINIMUM 32.5 33.3 -0.8 34.5
MEAN 47.8 47.4 0.4 48.9
DAYS MAX >= 90 0 0.0 0.0 0
DAYS MAX <= 32 0 0.3 -0.3 1
DAYS MIN <= 32 16 13.0 3.0 15
DAYS MIN <= 0 0 0.0 0.0 0
PRECIPITATION (INCHES)
RECORD
MAXIMUM 8.24 1900
MINIMUM 0.03 1963
TOTALS 0.86 1.71 -0.85 0.98
DAILY AVG. 0.03 0.06 -0.03 0.03
DAYS >= .01 8 9.1 -1.1 10
DAYS >= .10 4 4.5 -0.5 5
DAYS >= .50 0 0.9 -0.9 0
DAYS >= 1.00 0 0.5 -0.5 0
GREATEST
24 HR. TOTAL 0.34 04/21 TO 04/21 04/29 TO 04/29
OBSERVED NORMAL DEPART LAST YEAR`S
SNOWFALL (INCHES)
TOTALS 1.5 6.8
DEGREE_DAYS
HEATING TOTAL 509 529 -20 478
SINCE 7/1 5250 5731 -481 4803
COOLING TOTAL 2 1 1 0
SINCE 1/1 2 1 1 0
FREEZE DATES
RECORD
EARLIEST 09/08/1962
LATEST 06/08/2007
EARLIEST 10/07
LATEST 05/05
.................................................................
WIND (MPH)
AVERAGE WIND SPEED 12.5
RESULTANT WIND SPEED/DIRECTION M
HIGHEST WIND SPEED/DIRECTION 46/320 DATE 04/13
HIGHEST GUST SPEED/DIRECTION 70/280 DATE 04/17
SKY COVER
POSSIBLE SUNSHINE (PERCENT) MM
AVERAGE SKY COVER 0.60
NUMBER OF DAYS FAIR 6
NUMBER OF DAYS PC 17
NUMBER OF DAYS CLOUDY 7
AVERAGE RH (PERCENT) 49
WEATHER CONDITIONS. NUMBER OF DAYS WITH
THUNDERSTORMS 3 MIXED PRECIP 0
HEAVY RAIN 0 RAIN 2
LIGHT RAIN 9 FREEZING RAIN 0
LT FREEZING RAIN 0 HAIL 0
HEAVY SNOW 0 SNOW 2
LIGHT SNOW 8 FOG W/VIS <=1/4 MILE 1
FOG 8 HAZE 2
- INDICATES NEGATIVE NUMBERS.
R INDICATES RECORD WAS SET OR TIED.
MM INDICATES DATA IS MISSING.
T INDICATES TRACE AMOUNT.
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