All posts by Thornton Weather

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

April 2018 weather recap: Dry conditions, temperatures a bit warmer than normal

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.

Click here to view Thornton’s April 2018 climate report.

Thornton, Colorado's April 2018 temperature summary. (ThorntonWeather.com)
Thornton, Colorado’s April 2018 temperature summary. (ThorntonWeather.com)
Thornton, Colorado's April 2018 precipitation summary. (ThorntonWeather.com)
Thornton, Colorado’s April 2018 precipitation summary. (ThorntonWeather.com)
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.

Thornton’s May weather preview: Snow to severe storms

Thornton, Colorado May 2013 weather preview.
Thornton, Colorado May 2016 weather preview.

Colorado’s famously highly variable weather seems to showcase itself during the month of May when a variety of weather conditions can be seen.

Winter-like temperatures and snow are possible as are mid-summer like temperatures or the more typical spring severe weather.

We begin May 2018 with cool, damp conditions to be followed by a string of mild, pleasant days.  Long range forecasts lean toward we warmer than normal month and one with potentially higher than average precipitation.

The month can bring extremes.  Snow is not entirely uncommon during the month, oftentimes causing damage to newly bloomed trees.  More common however 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.

For a complete look at what lies ahead for the month of May, check out our full preview here.

Denver ties record high temperature for April 29

Record High TemperaturesA toasty spring day in the Mile High City.  Afternoon cloud cover cooled things down but not before we tied a record high temperature for today dating to 1948.

At DIA where Denver’s official measurements are taken, the high temperature reached 83 degrees.  Here in Thornton, we were just a bit warmer with a high of 84 degrees.

Both readings were far and above the average high for today’s date of 65 degrees.

Tomorrow promises to be another mild day with highs in the mid-70s but then the weather turns cooler and a bit more unsettled with chances for precipitation Tuesday, Wednesday and Thursday. See our extended forecast for details.

  • Stay up to date with Thornton’s weather: ‘Like’ us on Facebook, follow us on Twitterand add us to your Google+ circles

April 2018 top shots: Monthly photo slideshow

A Fox vixen hangs out on a pleasant spring evening. (J Martin)
A Fox vixen hangs out on a pleasant spring evening. (J Martin)

April can be a tricky month weather-wise with everything from mild temperatures to snow to severe weather being possible.  The good thing about that is that it provides plenty of chances for great photos!

April marks a transition between winter and summer for most of the country but for Denver it is especially true as we can see a stunning variety of weather.

The proverbial April showers are certainly a possibility for Denver. Snow? Tornadoes? Thunderstorms? You bet – all can happen!

Throw in our usual wildlife plus the wide variety of birds that return to the Centennial State for the spring and summer and there is a lot going on.

  • Slideshow updated April 29, 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=”72157665882943537″]

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!

April 22 to April 28: This week in Denver weather history

This week in Denver weather history
April 22 to April 28: This week in Denver weather history

Certainly April can bring pleasant weather but it also can bring thunderstorms and even heavy, damaging snow as we see in our look back at this week in Denver weather history.

From the National Weather Service:

19-22

In 1933…a major storm dumped 16.8 inches of snowfall over downtown Denver when rain changed to snow during the early morning of the 20th and continued through midday of the 22nd. Most of the snow fell on the 21st. Due to melting… The most snow on the ground was 10.5 inches at 6:00 pm on the 21st. Before the snow started…a strong cold front on the evening of the 19th produced north winds sustained to 35 mph with gusts to 37 mph. The strong winds deposited a thin layer of dust on the city. North to northwest winds were sustained to 31 mph with gusts to 35 mph on the 20th and to 29 mph with gusts to 32 mph on the 21st.

20-22

In 1957…strong and gusty south to southeast winds raked metro Denver each day. The strongest wind gust of 55 mph occurred on the 21st when blowing dust briefly reduced the visibility to 3/4 mile at Stapleton Airport.

20-23

In 1989…unusually warm weather resulted in several daily temperature records being broken in Denver. The high temperature of 89 degrees on the 21st exceeded the record maximum for the month at that time. Daily record high temperatures were either exceeded or equaled with 83 degrees on the 20th…88 degrees on the 22nd…and 85 degrees on the 23rd. The low temperature of 55 degrees on the 22nd equaled the record high minimum for the date.

21-22

In 1910…north winds were sustained to 45 mph behind a cold front. Rainfall totaled 0.63 inch.

In 1923…snowfall of 2.0 inches in the city was the only snow of the month and the last measurable snow of the season. Northwest winds were sustained to 25 mph on the 21st.

In 1952…heavy snowfall totaled 7.6 inches at Stapleton Airport. The storm was accompanied by north winds gusting to 33 mph.

In 2001…the second major snow storm in 11 days moved into metro Denver with blizzard conditions developing again across the plains to the northeast of Denver. Snowfall amounts ranged up to 9 inches in metro Denver with up to 23 inches in the foothills. Northwest winds were sustained at 20 to 30 mph with gusts as high as 36 mph at Denver International Airport which was again shut down for nearly an hour by power outages on the 22nd. The outages affected lighting in the concourses…train operations…de-icing and refueling operations…flight information displays…and security screenings. Navigational aids were also affected… Resulting in the cancellation of 58 arriving and departing flights which stranded about 5000 passengers. Across metro Denver storm totals included: 9 inches at Eldorado Springs; 7 inches in Boulder; 6 inches at Ken Caryl…Northglenn and near Sedalia; and 5 inches in Arvada and Morrison. Only 1.7 inches of snow were measured at the site of the former Stapleton International Airport. In the foothills snow totals included: 23 inches near Fritz Peak south of Rollinsville…17 inches near Jamestown…16 inches near Blackhawk…14 inches in Coal Creek Canyon…13 inches at Idaho Springs and near Nederland…11 inches at Aspen Springs…and 10 inches near Bergen Park.

21-23

In 1999…a spring snowstorm dumped heavy snowfall over metro Denver and in the foothills. Nearly 3 feet of snow fell in the foothills with over a foot in the city. The heavy wet snow downed power lines in Douglas and Elbert counties. Scattered outages were reported at Parker…Franktown… Sedalia…and Castle Rock. Some residents were without electricity for as long as 20 hours. The inclement weather was blamed…at least in part…for several traffic accidents along the I-25 corridor between Denver and Castle Rock. Snowfall totals included: 32 inches at Idaho Springs; 31 inches on Crow Hill; 29 inches near Evergreen; 26 inches at Chief Hosa and Coal Creek Canyon; 25 inches at Bailey; 24 inches at Floyd Hill; 23 inches at conifer…Genesee…Golden Gate Canyon…North Turkey Creek…and Pine Junction; 13 inches at Broomfield and near Sedalia; 12 inches in Boulder; 11 inches at Louisville and Parker; and 9 inches at the site of the former Stapleton International Airport.

In 2004…heavy snow fell across metro Denver…when low level upslope conditions developed against the foothills and Palmer Divide. Snowfall totals included: 18 inches in the foothills southwest of Boulder…17 inches at Intercanyon and near Conifer…10 inches near Blackhawk and Parker…9 inches at Castle Rock and near Sedalia…7 inches in Centennial… Littleton…and near Lone Tree. Elsewhere across metro Denver…snowfall generally ranged from 2 to 5 inches. Snowfall was 4.7 inches at Denver Stapleton. Northwest winds gusted to 35 mph at Denver International Airport on the 21st.

22

In 1896…southwest winds were sustained to 39 mph with gusts as high 56 mph. The apparent Chinook winds warmed the temperature to a high of 78 degrees.

In 1904…west winds sustained to 40 mph with gusts to 48 mph warmed the temperature to a high of 69 degrees.

In 1925…southeast winds sustained to 42 mph with gusts to 46 mph warmed the temperature to a high of 76 degrees.

In 1958…west-northwest winds gusted to 48 mph at Stapleton Airport.

22-23

In 1885…the worst snow storm since station records began in 1872 dumped a total of 24.0 inches of snowfall on the city. The 23.0 inches of snow recorded on the 22nd and 23rd was the greatest 24-hour snowfall ever recorded during the month of April. Streets were impassable…roofs caved in… Telegraph and telephone wires were downed…railroads were blocked and trains delayed…and most business came to a complete standstill. Estimated losses were reported to 50 thousand dollars. The total snowfall was partly estimated due to melting. Precipitation from the storm totaled 2.79 inches.

In 1915…post-frontal rain during the day and overnight totaled 2.00 inches. Most of the rain fell on the 22nd.

In 1945…6.7 inches of snow fell over downtown Denver. This was the third major snow in a little over 3 weeks…which made this month the 4th snowiest on record. Northeast winds were sustained to 25 mph and light hail fell on the 22nd.

In 2013…a spring storm brought heavy snow to the mountains… with period of moderate to heavy snow to portions of the Front Range Foothills and Urban Corridor. In the mountains and foothills…storm totals included: 18 inches at Niwot Ridge SNOTEL; 16.5 inches near Ward; 13 inches at Arapahoe Basin and Roach SNOTEL…12 inches near Blackhawk; 11.5 inches near Nederland; 11 inches near Allenspark and at Loveland Ski Area; 10 inches near Idaho Springs and Pinecliffe; with 9.5 inches and near Silverthorne. Along the Urban Corridor storm totals included: 7.5 inches near Morrison; 7 inches at the National Weather Service Office in Boulder and Niwot; 6.5 inches near Arapahoe Park and Superior; with 6 inches at Lafayette and Lakewood. At Denver International Airport…4.7 inches of new snowfall was observed.

22-24

In 2010…a potent spring storm brought heavy…wet snow to areas in and near the Front Range foothills and widespread rainfall across the adjacent plains. In the Front Range foothills and north-central mountains east of the Continental Divide…storm totals ranged from 15 to 30 inches. Storm totals included: 29.5 inches…3 miles southeast of Pinecliffe; 27 inches…8 miles northeast of four corners; 23 inches at Willow Creek; 22.5 inches… 13 miles northwest of Golden; 21 inches at Never Summer; 17 inches at Eldorado Springs; 16.5 inches…3 miles west of Jamestown. Denver International Airport reported just a trace of snowfall…but measured 2.01 inches of rainfall for the duration of the storm. In addition…a peak wind gust to 54 mph from the northwest was observed at the airport on the 23rd

Continue reading April 22 to April 28: This week in Denver weather history

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

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

As we enter the latter half of April the weather history calendar starts to reflect shift in the type of weather events we see. There are still plenty of significant snowfall events. However spring severe weather starts to appear with greater frequency including heavy rain, hail and even tornadoes.

From the National Weather Service:

12-15

In 1927…snowfall totaled 8.5 inches in downtown Denver. Most of the snow fell on the 14th. Northwest winds were sustained to 27 mph during the storm.

13-15

In 1945…heavy snowfall totaled 9.8 inches in downtown Denver. Most of the snow…4.8 inches…fell on the 14th. Snow fell for a total of 53 consecutive hours. This was the second big snow in less than 2 weeks. The air mass was very cold for April. High temperatures of 21 degrees on the 14th and 32 degrees on the 15th were record low maximums for the those dates.

13-17

In 2001…a huge dust storm over southern and inner Mongolia during April 3rd through the 6th lifted desert dust into the jet stream. This dust cloud moved over metro Denver on the 13th and persisted through the 17th. The cloud created widespread haze…giving the sky a milkish cast due to the scattering of incoming solar radiation.

14-15

In 1873…north winds blew a gale during the afternoon on both days. Winds were brisk throughout each day.

In 1902…snowfall totaled 6.0 inches in downtown Denver. Most of the snow melted as it fell. Northeast winds were sustained to 20 mph.

In 1910…strong winds occurred on both days. Northeast winds were sustained to 52 mph on the 14th. North winds were sustained to 44 mph on the 15th.

In 1921…heavy snowfall and strong winds produced near- blizzard conditions in the city. Snowfall totaled 10.0 inches. Strong north winds sustained to 48 mph with gusts to 54 mph on the 15th produced drifts to several feet in depth. The heavy wet snow caused extensive damage to trees…utility poles…and buildings. Precipitation from the storm was 1.73 inches. Very heavy snow also fell in the foothills. At Silver Lake…in the mountains west of Boulder…95 inches of snow fell in 32.5 hours on the 14th and 15th.

In 1935…dense dust…apparently behind a dry cold front… Enveloped the city at 1:00 pm on the 14th and persisted through the night. The dust blew into the city on northeast winds sustained to 30 mph with gusts to 32 mph. By mid-morning on the 15th…the dust had become light and continued as such into the evening. North winds were sustained to only 13 mph on the 15th.

In 1999…a spring storm dumped heavy snow over portions of metro Denver. Nearly 2 feet of snow fell in the foothills with half a foot to a foot over western and southern suburbs. The heavy snow alleviated drought conditions and associated high fire danger that prevailed during much of the winter season. Snowfall totals included: 22 inches in Coal Creek Canyon…20 inches at Wondervu…19 inches at Genesee…17 inches near Evergreen and Nederland and at Idaho Springs and Tiny Town…14 inches at Georgetown…13 inches at Morrison…10 inches near Sedalia…9 inches in south Boulder… 8 inches at Highlands Ranch and Wheat Ridge…and 7 inches at Littleton and Parker. Only 3.4 inches of snow fell at the site of the former Stapleton International Airport. North- northwest winds gusted to 41 mph on the 15th at Denver International Airport.

15

In 1874…light snow developed around daybreak and became moderate to heavy by mid-morning and continued into the early evening. While most of the snow melted as it fell… Total precipitation from the melted snow was 0.95 inch. This would make the estimated snowfall nearly 10 inches.

In 1963…high winds were widespread across metro Denver. West winds gusted to 63 mph in Denver at Stapleton Airport with sustained winds of 35 mph and gusts to 70 mph in downtown Boulder. The winds caused extensive damage to buildings and other property. Visibility was briefly reduced to 1/2 mile in blowing dust at Stapleton Airport.

In 1998…another spring storm brought heavy snow to the foothills. Thirty to 40 vehicles were involved in accidents along I-70 near Georgetown. The combination of poor visibilities…slick roads…and careless drivers led to the multi-car pileups. Only minor injuries were reported. The accidents forced the closure of all of I-70’s eastbound lanes. Snowfall totals included 12 inches at Genesee and 10 inches at Aspen Springs…Chief Hosa…Georgetown…near Morrison…and on North Turkey Creek. Only 0.1 inch of snow fell at the site of the former Stapleton International Airport. East winds gusted to 30 mph at Denver International Airport.

In 2002…unseasonable warm weather resulted in two records being broken. The high temperature of 84 degrees was a record maximum for the date. The low temperature of 57 degrees was a record high minimum for the date.

15-16

In 1900…heavy rainfall totaled 2.33 inches. A trace of snow was mixed with the rain at times.

In 1950…thunderstorms and heavy rain behind a cold front produced 2.13 inches of rain in 24 hours at Stapleton Airport.

In 2003…a fast moving pacific storm system moved across Colorado allowing strong winds to develop over the eastern foothills and metro Denver. Northwest winds gusted to 59 mph at Denver International Airport late in the evening of the 15th.

15-17

In 1922…heavy snowfall totaled 9.0 inches in downtown Denver. Most of the snow…6.0 inches…fell on the 16th. This was the third major snow storm in a week. Northwest winds were sustained to 43 mph with gusts to 47 mph on the 15th.

16

In 1960…a wind storm struck all of metro Denver. Estimated wind gusts up to 80 mph were registered in Boulder. At Stapleton Airport sustained west-northwest winds over 50 mph with gusts as high as 70 mph produced some blowing dust. The high winds damaged buildings…power and telephone lines…and signs. Five people were injured in metro Denver as a result of the wind storm. Blowing dust reduced visibility at times. The winds were strong and gusty for most of the day.

16-17

In 1944…heavy snowfall totaled 7.5 inches in downtown Denver. Northwest winds were sustained to 18 mph on the 16th.

16-18

In 2009…a potent spring storm brought heavy snow to locations in and near the Front Range foothills. A deep easterly upslope produced nearly 5 feet of snow in parts of the foothills. The heavy snow resulted in the closure of Interstate 70…from Golden west to Vail…for approximately 16 hours. The heavy snow snapped power lines in Evergreen and Nederland. The ensuing outages affected 14200 residents. In the Front Range foothills…storm totals included: 56 inches…3 miles south of Rollinsville; 54 inches…3 miles southeast of Pinecliffe…43 inches at Aspen Springs…42 inches at Evergreen…38 inches near conifer; 37 inches at St. Mary’s glacier…and 34 inches near Nederland. Along the urban corridor and Palmer Divide…the heaviest snow occurred above 5500 feet on the 17th. Storm totals included: 22 inches…8.5 miles southwest of Franktown; 18 inches…10 miles south-southeast of Buckley Air Force Base; 17 inches near Cherry Creek and 7 miles south of Sedalia… 16 inches…6.5 miles southwest of Castle Rock; 15 inches near Beverly Hills; 12 inches near Highlands Ranch and Lafayette…with 11 inches in Broomfield. Elsewhere storm totals ranged from 4 to 10 inches. Officially…only 2.6 inches of snow was observed at Denver International Airport. The 24-hr precipitation for the day however was 1.16 inches… Which established a new record for April 17th.

Continue reading April 15 to April 21: This week in Denver weather history

April 8 to April 14: This week in Denver weather history

This week in Denver weather history
April 8 to April 14: This week in Denver weather history

April can be a very eventful weather month and we see that in our look back at this week in Denver weather history. Particularly notable are many major snow events including two in recent history – one in 2001 and another in 2005.

From the National Weather Service:

6-8

In 1973…a major spring snow storm dumped 11.6 inches of snowfall over metro Denver. North wind gusts of 30 to 35 mph produced some blowing snow. Most of the heavy wet snow… 10.1 inches…fell on the 7th when temperatures remained in the 20’s. Snow accumulated on the ground to a maximum depth of 9 inches. Low temperature of 5 degrees on the 8th was a new record minimum for the date and the lowest for so late in the season.

7-9

In 1913…heavy snowfall totaled 10.9 inches in downtown Denver behind a cold front. Most of the snow fell on the 8th. Northeast winds were sustained to 35 mph with gusts to 38 mph on the 9th.

In 1935…moderate dust blew into the city around 9:00 pm on the 7th and persisted until early afternoon on the 9th. Southeast winds were sustained to around 20 mph on the 7th and 8th. Winds shifting to the west at sustained speeds to 20 mph cleared the dust from the air on the 9th.

7-12

In 1959…snow falling over a 5-day period totaled 20 to 30 inches just east of the mountains…while over the plains blizzard conditions closed schools and blocked highways. The second big storm in two weeks dumped 16.4 inches of snowfall on Stapleton Airport with the most…11.6 inches… Occurring on the 8th. East winds gusted to 37 mph on the 9th. Temperatures dipped into the single digits on the mornings of the 7th and 12th when 7 degrees were registered. Low temperature records for the dates were set on the 9th…10th…and 12th. The cold temperatures caused streets to glaze with ice…resulting in the death of a pedestrian who was struck by a car in Denver. Three people died from heart attacks while shoveling the heavy… Wet snow.

8

In 1885…dense smoke polluted the air until noon.

In 1887…south winds were sustained to 42 mph.

In 1890…northwest winds were sustained to 48 mph with gusts as high as 60 mph.

In 2005…a mixture of strong pressure gradient winds coupled with thunderstorm outflow winds produced high winds across metro Denver. The high winds downed power lines and knocked out electricity to about 19 thousand customers on the east side of metro Denver. High wind reports included gusts to 68 mph in Longmont…61 mph near Castle Rock…59 mph at Centennial Airport…and 54 mph at Denver International Airport.

8-9

In 2013…heavy snow developed in and near the Front Range Foothills and Palmer Divide as an upper level trough made its way across southern Colorado. Snowfall was enhanced locally with the presence of an upper level jet. Storm totals included: 23 inches near Eldorado Springs…18 inches just west of Boulder…16.5 inches near Orodell…15 inches…4 miles west-northwest of Boulder; 13 inches at Gold Hill; 12 inches at the National Weather Service Office in Boulder…11 inches in Ken Caryl; 8.5 inches near Morrison; 8 inches at Genesee and Roxborough Park; 7.5 inches near Arapahoe Park; with 6.5 inches at Denver International Airport.

8-10

In 1999…a windstorm caused 20 million dollars in damage along the Front Range urban corridor from Fort Collins south to pueblo and to the east over the plains…making the storm equal to the costliest windstorm ever…which occurred in Boulder on January 17…1982. In metro Denver… Several homes were damaged as shingles were blown off roofs. Large pieces of a roof torn off a strip mall in Lakewood damaged several cars in a parking lot. Most of the damage to homes consisted of broken fences…awnings…doors…and windows. Scores of automobiles suffered broken or cracked windshields and paint damage from flying debris. Multiple accidents were triggered as several tractor-trailer rigs were blown on their sides by the strong cross-winds. Blowing dust and dirt caused near zero visibilities at times. Both I-25 and I-76 were closed north and northeast of Denver. State Highway 93 was closed between Golden and Boulder. Several trees…power poles…and power lines were downed…causing a number of outages as well as sparking a few small grass fires. Highest wind gusts reached 112 mph atop Niwot Ridge near the continental divide west of Boulder…102 mph at Wondervu…100 mph at the National Center for Atmospheric Research mesa lab in Boulder…98 mph at the national wind technology center near Broomfield…96 mph on Rocky Flats…92 mph at Jefferson County Airport near Broomfield and on the University of Colorado campus in Boulder…and 90 mph at Highlands Ranch in southwest metro Denver. Winds gusted to 48 mph at Denver International Airport.

9

In 1950…strong southwest winds gusting to 58 mph reduced the visibility to 1 mile in blowing dust at Stapleton Airport. Scattered minor wind damage…consisting of falling tree branches and damage to signs…occurred across metro Denver.

In 1989…6 to 12 inches of snow fell at many locations in the Front Range foothills. Boulder received 6 to 8 inches. Five inches (5.0 inches) of snow fell at Stapleton International Airport…causing 2 hour flight delays. I-25 south of Denver was closed for 4 hours due to a 100- car traffic pileup. North winds gusted to 33 mph at Stapleton International Airport where the maximum snow depth on the ground was only 3 inches due to melting.

9-10

In 1900…rain changed to heavy snow and totaled 6.8 inches in downtown Denver overnight. A thunderstorm occurred on the 9th. North winds were sustained to 32 mph with gusts to 38 mph on the 10th. Precipitation totaled 1.39 inches.

In 1933…post-frontal heavy snowfall totaled 9.4 inches in downtown Denver. East winds were sustained to 21 mph with gusts to 22 mph on the 9th.

In 1944…7.0 inches of snow fell on downtown Denver. Northeast winds were sustained to 24 mph on the 9th.

In 1977…the two warmest days of the month resulted in two temperature records being set. High temperature of 81 degrees on the 9th set a new record maximum for the date. High temperature of 80 degrees on the 10th equaled the record maximum for the date. The unusually warm weather for so early in April produced a late afternoon thunderstorm on the 10th.

In 1993…strong downslope winds occurred along the Front Range. While the strongest winds were in the foothills north of Denver…wind gusts to 69 mph were recorded at Jefferson County Airport in Broomfield. Northwest winds gusted to 39 mph at Stapleton International Airport.

In 2004…a spring storm brought heavy snow to metro Denver. The heaviest snow fell in the foothills and over and near higher terrain. Snowfall totals included: 20 inches near Jamestown; 18 inches atop gold hill; 17 inches near Evergreen; 15 inches at Nederland and Eldora; 13 inches at Blackhawk; 11 inches at Aspen Springs; 9 inches in Louisville; 8 inches at Ken Caryl; 6 inches at Niwot… Near Sedalia…and in Thornton; 5 inches in Lakewood… Lyons…and Westminster. Snowfall was 4.4 inches at Denver Stapleton. Northwest winds gusted to 21 mph at Denver International Airport.

In 2008…a very moist storm brought heavy snow to parts of the Front Range foothills. Storm totals included: 12.5 inches at Aspen Springs…11 inches…4 miles west- southwest of conifer; with 10.5 inches…3 miles north of central city and 6 miles southwest of Evergreen. Lesser amounts of 5 to 9 inches were observed elsewhere. North winds gusted to 43 mph at Denver International Airport on the 10th…and 1.8 inches of snow fell at the former Stapleton International Airport.

9-11 Continue reading April 8 to April 14: This week in Denver weather history

March 2018 weather recap: A warmer, wetter than normal month

The month was one largely bereft of any true weather drama.  It started out quite warm and dry and while we chilled out and got wetter for the second half, there were no significant events of note.

The first couple of weeks of March were notable for their largely warmer than normal temperatures and their lack of precipitation. It wasn’t until the 15th when we finally saw some moisture.

The latter half of the month did turn largely cooler although there was a period from the 21st to the 25th with unseasonably warm mercury readings.  Beyond that, things remained cool and we received a few, minor shots of snow and rain.

In the end, the average temperatures for the month were above normal and while snowfall was less than normal, we recorded above average levels of precipitation.

The overall average temperature in Thornton for the month was 42.6 degrees.  This was a good bit above Denver’s long term average for the month of 40.4 degrees. In the Mile High City at Denver International Airport where official measurements are kept, a similar average of 42.7 degrees was seen.

Temperatures in Thornton ranged from a maximum of 74.2 degrees on the 22nd down to a low of 16.6 degrees on the 7th.  At DIA, the warmest reading was 73 degrees and the coldest 13 degrees, both on the same days as our warmest / coldest readings.

In terms of precipitation, Thornton saw 1.25 inches of liquid precipitation. Denver lagged us with 1.02 inches.  Both measurements, however, were above the March long term average of 0.92 inches.

March is usually one of our snowier months with an average of 10.7 inches recorded during the month. We fell a long ways short of that however with Thornton seeing 6.2 inches of the white stuff and Denver only 4.8 inches.

Click here to view Thornton’s March 2018 climate report.

Thornton, Colorado's March 2018 temperature summary. (ThorntonWeather.com)
Thornton, Colorado’s March 2018 temperature summary. (ThorntonWeather.com)
Thornton, Colorado's March 2018 precipitation summary. (ThorntonWeather.com)
Thornton, Colorado’s March 2018 precipitation summary. (ThorntonWeather.com)
CLIMATE REPORT
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
840 AM MDT SUN APR 1 2018

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

...THE DENVER CO CLIMATE SUMMARY FOR THE MONTH OF MARCH 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              84   03/26/1971
 LOW              -11   03/28/1886
HIGHEST            73   03/22        84     -11       81  03/18
LOWEST             13   03/07       -11      24       14  03/01
AVG. MAXIMUM     58.5              54.4     4.1     64.0
AVG. MINIMUM     26.8              26.4     0.4     31.9
MEAN             42.7              40.4     2.3     47.9
DAYS MAX >= 90      0               0.0     0.0        0
DAYS MAX <= 32      0               1.9    -1.9        0
DAYS MIN <= 32     27              23.6     3.4       16
DAYS MIN <= 0       0               0.1    -0.1        0

PRECIPITATION (INCHES)
RECORD
 MAXIMUM         4.56   1983
 MINIMUM         0.03   2012
TOTALS           1.02              0.92    0.10     0.90
DAILY AVG.       0.03              0.03    0.00     0.03
DAYS >= .01         6               5.9     0.1        6
DAYS >= .10         3               2.4     0.6        3
DAYS >= .50         0               0.3    -0.3        0
DAYS >= 1.00        0               0.1    -0.1        0
GREATEST
 24 HR. TOTAL    0.33   03/18 TO 03/18           03/24 TO 03/24


         OBSERVED                 NORMAL  DEPART  LAST YEAR`S

SNOWFALL (INCHES)
TOTALS            4.8              10.7

DEGREE_DAYS
HEATING TOTAL     684               763     -79      523
 SINCE 7/1       4741              5202    -461     4325
COOLING TOTAL       0                 0       0        0
 SINCE 1/1          0                 0       0        0

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

WIND (MPH)
AVERAGE WIND SPEED              11.5
RESULTANT WIND SPEED/DIRECTION   2/218
HIGHEST WIND SPEED/DIRECTION    46/280    DATE  03/05
HIGHEST GUST SPEED/DIRECTION    64/290    DATE  03/23

SKY COVER
POSSIBLE SUNSHINE (PERCENT)   MM
AVERAGE SKY COVER           0.50
NUMBER OF DAYS FAIR            8
NUMBER OF DAYS PC             22
NUMBER OF DAYS CLOUDY          1

AVERAGE RH (PERCENT)     46

WEATHER CONDITIONS. NUMBER OF DAYS WITH
THUNDERSTORMS             1   MIXED PRECIP           2
HEAVY RAIN                0   RAIN                   5
LIGHT RAIN                5   FREEZING RAIN          0
LT FREEZING RAIN          0   HAIL                   0
HEAVY SNOW                2   SNOW                   4
LIGHT SNOW                7   FOG W/VIS <=1/4 MILE   2
FOG                       7   HAZE                   1

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

April 1 to April 7: This week in Denver weather history

This week in Denver weather history
April 1 to April 7: This week in Denver weather history

As we pointed out in our April weather preview, the month can bring just about any type of weather condition and we see that in our look back at this week in Denver weather history. From powerful, damaging winds to Arctic cold to heavy snowfall this has been an eventful week in the past.

From the National Weather Service:

31-1

In 1876…heavy snow began during the night and lasted all day on the 31st and through the morning of the 1st. The average depth of snow fall was 10 to 12 inches…but strong winds whipped the snow into drifts of 8 to 10 feet deep on the streets of the city. Precipitation from the storm was 1.03 inches on the 31st and 0.37 inch on the 1st.

In 1891…heavy moist snowfall totaled 18.0 inches in the city. Northeast winds were sustained to 20 mph with gusts to 24 mph on the 31st.

In 1936…northeast winds sustained to 21 mph produced a light dust storm in the city.

In 1975…a major storm dumped 9.3 inches of snowfall at Stapleton International Airport where northwest winds gusted to 41 mph. Rain changed to snow on the afternoon of the 31st…reducing the visibility to as low as 1/8 mile. Snow continued all day on the 1st and accumulated to a depth of 8 inches on the ground. The minimum temperature of 10 degrees on the 1st set a new record low for the date.

31-2

In 1980…the second major blizzard in 5 days buried much of eastern Colorado under 6 to 12 inches of snow. Some drifts were up to 22 feet high. Hundreds of travelers were stranded. Over 3000 families were without power. Livestock losses were high. Metro Denver escaped the main brunt of this storm. At Stapleton International Airport…only 6.3 inches of snow fell over the 3-day period and north winds gusted to only 22 mph on the 1st.

31-3

In 1979…total snowfall of 6.6 inches was measured at Stapleton International Airport where north winds gusted to 31 mph on the 31st. The greatest accumulation of snow on the ground was 3 inches on the 1st.

31-4

In 1905…much rain and some snow occurred over the 5 days behind an apparent cold front. Precipitation totaled 2.00 inches. There was a thunderstorm on the 3rd. Snowfall totaled 3.0 inches on the 4th. North winds were sustained to 34 mph on the 1st and 2nd and to 30 mph on the 3rd. High temperatures during the period ranged from the upper 30’s to the lower 40’s. Low temperatures were in the upper 20’s and lower 30’s.

1

In 1987…a vigorous cold front produced 2.3 inches of snowfall at Stapleton International Airport where northeast winds gusted to 39 mph. The temperature dropped from a maximum of 59 degrees at mid-morning to a low of 25 degrees at midnight.

1-2

In 1963…strong winds buffeted metro Denver…while wind- whipped fires consumed grassland on the plains. A child was injured by a windblown falling tree in Castle Rock. Southwest winds gusted to 52 mph at Stapleton Airport… Causing some blowing dust. The worst fire storm burned over 25 thousand acres of grazing land in southern Weld County near Roggen northeast of Denver.

In 1984…a snowstorm with near-blizzard conditions over eastern Colorado closed many roads…including I-70 and I-76 east of Denver and I-25 between Denver and Colorado springs. At Stapleton International Airport…snowfall totaled only 2.5 inches…but north winds gusted to 45 mph on the 2nd.

In 1999…moist upslope conditions allowed heavy snow to develop in the Front Range foothills where snowfall totals included: 10 inches at Aspen Park and Evergreen; 9 inches at Turkey Creek; 8 inches at Idaho Springs and Genesee; 7 inches at Aspen Springs…Crow Hill…Intercanyon…and Lake George. In metro Denver snowfall totals included: 10 inches south of Sedalia; 8 inches in Littleton; 7 inches at Morrison; 6 inches at Highlands Ranch; and 4 to 5 inches in Northglenn…Parker and near Louisville. Snowfall totaled 4.7 inches at the site of the former Stapleton International Airport.

1-3

In 1945…snow fell across metro Denver for a total of 51 consecutive hours. While the storm was not accompanied by excessive snow…the long duration made the event a heavy snow producer. Snowfall totaled 10.7 inches in downtown Denver with 9.5 inches recorded at Stapleton Airport. North winds were sustained to 21 mph on the 1st; otherwise winds were not strong. The air mass was very cold for April. The high temperatures of 26 on the 2nd and 17 on the 3rd were record low maximums for the dates. The latter was also a record low maximum for the month. Warm weather following the storm quickly melted the snow.

In 1973…heavy snow fell at Stapleton International Airport where 8.7 inches were measured. Snow began late on the 1st and continued through early morning on the 3rd. Thunder accompanied the snow during the late morning and afternoon of the 2nd. North winds gusted to 33 mph on the 2nd and 37 mph on the 3rd. Snow only accumulated to a depth of 5 inches on the ground due to melting.

In 1977 a foot of snow fell in Boulder and Broomfield. The Denver-Boulder turnpike was closed for an hour after numerous minor traffic accidents. At Stapleton International Airport…snowfall totaled 4.7 inches and southeast winds gusted to 32 mph on the 2nd. The greatest depth of snow on the ground was only 3 inches due to melting.

2

In 1894…northwest winds were sustained to 42 mph with gusts to 48 mph. The warm Chinook winds warmed the temperature to a high of 70 degrees.

In 1925…north winds were sustained to 40 mph with gusts to 42 mph.

In 1957…a heavy snow storm dumped 17.3 inches of snow at Stapleton Airport. Strong gusty north winds to 31 mph reduced visibilities to 1/8 mile at times and created blizzard conditions. The 24-hour snowfall had been exceeded only twice in previous records…and the 24 hour precipitation of 2.05 inches was the third heaviest of previous record during April.

In 1959…a cold front produced strong gusty winds across metro Denver. North winds gusting to 50 and 60 mph caused some minor damage to power lines and signs and caused dust storms on the plains east of Denver. A wind gust to 49 mph was recorded at Stapleton Airport.

In 1966…northwest winds gusting to 52 mph produced blowing dust…which briefly reduced the visibility to 1 mile at Stapleton International Airport.

In 1975…the all-time lowest recorded temperature in April… 2 degrees below zero…occurred. This is also the latest below zero reading for the season.

In 1982…a strong windstorm struck all of metro Denver… Causing minor damage. Wind gusts to 127 mph were recorded at Rocky Flats south of Boulder…116 mph at Wondervu…100 mph at Jefferson County Airport in Broomfield…and 56 mph at Stapleton International Airport. The strong winds whipped up blowing dust…briefly reducing the visibility to 3/4 mile.

In 1986…heavy thunderstorms produced wind gusts to about 70 mph in Boulder. A severe thunderstorm wind gust to 62 mph was recorded at Stapleton International Airport. The strong winds kicked up thick clouds of blowing dust severely restricting surface visibility.

In 1997…a pacific storm left heavy snow in the foothills with lesser amounts across the city. Snowfall totaled 12 inches near Blackhawk…11 inches at Golden Gate Canyon…10 inches at Conifer and Crow Hill…9 inches at Evergreen…5 inches at Sedalia…and 4 inches at Castle Rock and Morrison. Only 2.1 inches of snow fell at the site of the former Stapleton International Airport. Northwest winds gusted to 21 mph at Denver International Airport.

In 1998…a major spring storm brought heavy snow to metro Denver and the foothills. Snowfall totals ranged from 12 to 22 inches in the foothills with 4 to 12 inches across metro Denver. Snowfall totals included: 22.5 inches near conifer; 13 inches in Coal Creek Canyon; 12 inches near Blackhawk…Eldora…and Genesee; 10 inches near Evergreen and Nederland; 9 inches in Lakewood; 8 inches in Broomfield and northwest Denver; and 7.0 inches at the site of the former Stapleton International Airport. Northeast winds gusted to 31 mph at Denver International Airport.

In 2002…snowfall was only a trace at the site of the former Stapleton International Airport. This was the only snowfall of the month…ranking the month…along with previous months… The 2nd least snowiest on record.

Continue reading April 1 to April 7: This week in Denver weather history

Thornton’s April 2018 preview: Winter, spring and summer all in one month

Thornton's April weather previewApril marks a transition between winter and summer for most of the country but for Denver it is especially true as we can see a stunning variety of weather.

The proverbial April showers are certainly a possibility for Denver. Snow? Tornadoes? Thunderstorms? You bet – all can happen!

For good measure throw in a chance for hail and even dust storms and April gives every type of weather condition you could like – or hate.