Category Archives: Weather History

News and related items pertaining to national, Colorado, Denver and Thornton weather.

November 14 to November 20 – This week in Denver weather history

November 14 to November 20 - This week in Denver weather history
November 14 to November 20 - This week in Denver weather history

Henry Fenton is probably not a name many folks are familiar with however he will forever be engrained in the Denver weather history books.  It was 139 years ago this week that Fenton made the first official Denver weather observations.

From the National Weather Service:

11-14

In 1970…heavy snowfall totaled 7.2 inches at Stapleton International Airport where northeast winds gusted to 22 mph on the 12th and 14th.  Most of the snow… 4.2 inches…fell on the 12th.

12-15

In 1909…light snowfall totaled 6.7 inches in downtown Denver over the 4 days.  This was the first measurable snowfall of the season.  Northeast winds were sustained to 15 mph on the 12th.

13-14

In 1925…heavy post-frontal snowfall totaled 6.4 inches overnight in downtown Denver.  Northwest winds were sustained to 27 mph with gusts to 29 mph on the 13th.
 
In 1974…northwest winds gusted to 52 mph at Stapleton International Airport…warming the temperature to 60 degrees shortly after midnight on the 13th.  A cold front cooled temperatures into the 20’s by late morning and produced snowfall of 3.7 inches.  The low temperature dipped to 14 degrees on the 14th.
 
In 1993…an upper level low pressure system combined with a weak but moist upslope flow to produce heavy snow across metro Denver.  Snowfall amounts averaged 6 to 8 inches with up to 16 inches in the foothills at the Eldora Ski Area. Snowfall totaled 6.0 inches at Stapleton International Airport where north winds gusted to only 20 mph on the 14th.  Most of the snow fell on the 14th.
 
In 1994…heavy snow developed rapidly along the Front Range urban corridor with the heaviest snow over northwest metro Denver.  Sixteen to 18 inches of snow fell in Boulder… Lafayette…and Louisville.  This was the second heavy snowfall over northwest metro Denver in 10 days.  Eleven to 14 inches of snow were measured from Longmont southward into Aurora.  Snowfall totaled 12.1 inches at Stapleton International Airport where northeast winds gusted to 29 mph on the 13th.  Most of the snow…9.0 inches…fell on the 14th.
 
In 1997…heavy snow fell overnight in portions of Jefferson and Boulder counties.  About 5.5 inches of snow were reported in Boulder…while 4 inches were measured 12 miles southwest of Morrison and 6 miles southwest of Golden. Snowfall totaled only 1.8 inches at the site of the former Stapleton International Airport.  Northeast winds gusted to 26 mph at Denver International Airport.

Continue reading November 14 to November 20 – This week in Denver weather history

October 31 to November 6 – This week in Denver weather history

October 31 to November 6 - This week in Denver weather history
October 31 to November 6 - This week in Denver weather history

Frightening weather does not seem to be in the cards for our Halloween or the immediate future.  That however is not always the case as we look back at this week in Denver weather history.

28-31

In 1929…rain changed to snow on the afternoon of the 28th and continued until midday on the 30th followed by intermittent light snow which continued through the 31st. Snowfall over the four days totaled 16.2 inches in the city.  Most of the snow…8.5 inches…fell on the 29th with 6.1 inches on the 30th.  Temperatures hovered in 20’s during most of the storm.

29-31

In 1889…the first snowfall of the season totaled 14.0 inches over the three days in downtown Denver.  Snowfall was 8.0 inches on the 29th and 5.0 inches on the 31st.  North to northeast winds gusted to 30 mph on the 29th.
 
In 1950…a warm spell resulted in five daily temperature records.  Record highs of 84…80…and 79 degrees occurred on the 29th…30th…and 31st…respectively.  Low temperature of 49 degrees on the 30th was the record high minimum for the date.
 
In 1991…the second surge of cold arctic air in a matter of days plunged metro Denver into the deep freeze.  While low temperatures remained above zero…high temperatures were only in the 20’s.  Three temperature records were set: record lows of 7 degrees on the 30th and 10 degrees on the 31st and a record low maximum of only 21 degrees on the 30th.  Snowfall was light with only 1.9 inches recorded at Stapleton International Airport where east winds gusted to 23 mph.
 
In 2002…snowfall totaled 4.3 inches at the site of the former Stapleton International Airport.  North winds gusted to 32 mph on the 29th behind a cold front…which plunged temperatures well below seasonal normals.  High temperatures of 18 degrees on the 30th and 19 degrees on the 31st were record low maximums for each date.  Low temperatures dipped to 12 degrees on the 30th and 15 degrees on the 31st.

Continue reading October 31 to November 6 – This week in Denver weather history

October 24 to October 30 – This week in Denver weather history

October 17 to October 23 – This week in Denver weather history
October 24 to October 30 - This week in Denver weather history

This year Denver is still waiting for its first snow and we have already passed the average date we see it (October 19).  That however isn’t always the case and October can bring monster snowstorms as we see in our look back at this week in Denver weather history.

From the National Weather Service:

23-24

In 1887…the first measurable snowfall of the season totaled 3.1 inches.  North winds to 20 mph were recorded on the 23rd.  This was the only measurable snow of the month.
 
In 1932…post-frontal snowfall from the late evening of the 23rd continued through the late afternoon of the 24th and totaled 6.2 inches.  Southeast winds were sustained to 25 mph with gusts to 26 mph on the 23rd.  Temperatures cooled from a high of 68 degrees on the 23rd to a low of 25 degrees on the 24th…the coldest reading of the month that year.  Many trees that had not shed their leaves became heavily laden by the wet snow.  Many branches were broken… And a few trees toppled under the weight of the snow.  The landscape became one of rare beauty.

24

In 1956…southwest winds gusted to 56 mph and produced some blowing dust at Stapleton Airport.  A cold front produced a thunderstorm with 1/8 inch hail.  Rain later changed to snow.  Precipitation totaled only 0.11 inch and snowfall only 0.3 inch.
 
In 1973…strong winds raked the eastern foothills…causing damage in Boulder and Jefferson counties.  The heaviest damage occurred in the Boulder area where 20 to 25 mobile homes were hit…some power and telephone lines were blown down…and a store was damaged.  A wind gust to 76 mph was recorded in Boulder at the National Bureau of Standards. Northwest winds gusted to 46 mph at Stapleton International Airport.

24-25

In 1921…rainfall totaled 0.35 inch overnight behind an apparent cold front.  North winds were sustained to 40 mph with gusts to 46 mph on the 25th.  Temperatures plunged from a high of 73 degrees on the 24th to a low of 39 degrees on the 25th.
 
In 1923…rain overnight changed to snow during the morning. The heavy snowfall accumulated to 12.0 inches before ending on the morning of the 25th.  Post-frontal north winds were sustained to 22 mph with gusts to 23 mph on the 24th.
 
In 1997…one of the worst and deadliest blizzards of the decade developed over eastern Colorado as deep east to northeast flow associated with a vigorous upper level low pressure system over the Four Corners…combined with a strong arctic air mass over the central Great Plains. Snowfall totals across metro Denver ranged from 14 to 31 inches.  The heaviest snowfall occurred in the foothills west and southwest of Denver where 2 to 4 feet of snow were measured.  Sustained winds to 40 mph with gusts as high as 60 mph produced zero visibilities and extremely cold wind chill temperatures from 25 below to 40 below zero.  Winds whipped the snow into drifts 4 to 10 feet deep.  Several major and interstate highways were closed as travel became impossible.  Red Cross shelters were set up for hundreds of travelers who became stranded when they had to abandon their vehicles.  Four people died in northeastern Colorado as a result of the blizzard.  None of the deaths were in metro Denver.  At Denver International Airport…4 thousand travelers were stranded when the airport was forced to shut down.  At least 120 cars were abandoned along Pena Blvd….the only arterial leading into and out of DIA.  The blizzard cost air carriers at least 20 million dollars.  Thousands of cattle died in the storm over northeastern Colorado…resulting in losses totaling 1.5 million dollars.  Some of the more impressive snowfall totals included:  51 inches at Coal Creek Canyon; 48 inches at Silver Spruce Ranch…near Ward; 42 inches at Intercanyon…in the foothills southwest of Denver; 37 inches at Sedalia; 35 inches at Aspen Springs and Conifer in the foothills west of Denver; 31 inches at Eldorado Springs… Southeast Aurora…and Englewood; and 30 inches on Table Mesa in Boulder.  Snowfall totaled 21.9 inches at the site of the former Stapleton International Airport…setting a new 24-hour snowfall record of 19.1 inches for the month. Snowfall totaled only 14 inches at Denver International Airport where north winds gusted to 39 mph on the 24th. High temperature of only 21 degrees on the 25th equaled the record low maximum for the date first set in 1873. Low temperature of only 3 degrees on the 26th set a new record minimum for the date.

Continue reading October 24 to October 30 – This week in Denver weather history

October 17 to October 23 – This week in Denver weather history

October 17 to October 23 – This week in Denver weather history
October 17 to October 23 – This week in Denver weather history

This year Denver is still waiting for its first snowfall but that certainly has not been the case throughout history.  Many times in our past we have seen not only snow around this time of October but heavy snow as well, oftentimes damaging in nature.

15-17

In 1989…an autumn snowstorm hit metro Denver with 2 to 6 inches of snow.  Snowfall totaled 4.4 inches at Stapleton International Airport where the maximum snow depth on the ground was only 3 inches due to melting and north winds gusted to 25 mph on the 15th.  The heavy wet snow caused leafy branches to sag onto power lines…resulting in a number of power outages.  Five thousand homes were blacked out in Boulder on the 16th.  Up to a foot of snow fell in the higher foothills with 19 inches recorded at Echo Lake.

16-17

In 1990…strong downslope winds raked the eastern foothills. Wind gusts from 60 to 75 mph were common.  Strong winds in metro Denver resulted in wave damage to a dock used to moor several private sail boats at Cheery Creek Reservoir. Damage was confined to the dock and two anchor cables. A northwest wind gust to 43 mph was recorded at Stapleton International Airport.

17 

In 1878…strong winds reached sustained speeds of 48 mph.
 
In 1988…a wind gust to 62 mph was recorded in central Boulder.  The strong winds caused a few brief power outages.  An old smoldering brush fire in the foothills west of Boulder was re-ignited by the wind gusts.
 
In 1994…winds gusted to 85 mph atop Squaw Mountain…5 miles south of Idaho Springs.
 
In 2006…a potent storm system brought heavy snowfall to the mountains and eastern foothills.  Snowfall totals in the foothills included:  14 inches at Blackhawk…13.5 inches near Idaho Springs…13 inches at cabin creek…12.5 inches at Aspen Springs and Echo Lake…11.5 inches at Georgetown and Rollinsville…10.5 inches near Jamestown…and 10 inches at grant and Lake Eldora.  Lesser snow amounts…from 4 to 9 inches…were recorded elsewhere in the foothills.  Snowfall totaled only 3.5 inches in the Denver Stapleton area.  At Denver International Airport…north winds gusted to 31 mph.

Continue reading October 17 to October 23 – This week in Denver weather history

October 10 to October 16 – This week in Denver weather history

October 10 to October 16 – This week in Denver weather history
October 10 to October 16 – This week in Denver weather history

The farther we get into fall the more we start seeing significant snow events in our look back at the week in history.  None of these is more famous than the “Bronco Blizzard” of 1984 that saw the Mile High City buried under nearly a foot of snow – on live television.

From the National Weather Service:

9-10

In 2005…a major winter storm brought heavy…wet snowfall to the Front Range mountains…eastern foothills…portions of metro Denver…and the Palmer Divide.  Snow accumulations ranged from 8 to 26 inches with drifts from 3 to 4 feet in places.  The heaviest snow occurred to the east and southeast of the city…closing most major highways in that area…including I-70 from Denver to Limon.  The Red Cross opened four shelters for people who were stranded along I-70 in eastern Colorado.  Since many trees had not yet shed their leaves…the storm caused significant tree damage.  One woman in Denver was killed when a tree branch… 8 to 10 inches in diameter…snapped under the weight of the heavy…wet snow and struck her as she was shoveling her driveway.  Xcel Energy reported power outages to about 35 thousand customers.  Several incoming flights were delayed at Denver International Airport.  Snow totals included:  16 inches in the foothills near Boulder…12 inches at Genesee and near Golden…22 inches near Watkins…19 inches near Bennett…17 inches southeast of Aurora…14 inches near Parker…13 inches near Castle Rock…12 inches in centennial… 11 inches in Parker…and 10 inches at Denver International Airport and in Littleton.  While many areas of metro Denver received heavy snow…others experienced almost entirely rain. This included west and northwest metro Denver…Boulder…and Longmont.  Rainfall amounts were significant as storm totals ranged between 1.50 and 2.50 inches.  The steady rainfall triggered 3 rockslides in foothills canyons.  Two of the slides occurred on State Highway 119 in Boulder canyon and the longest slide…7 feet in length…on State Highway 74 in Bear Creek Canyon at Idledale.  North winds were sustained to around 23 mph with gusts to 31 mph at Denver International Airport on the 9th.  The high temperature of only 34 degrees on the 10th was a record low maximum for the date.  The low temperature on both days was 32 degrees.

10 

In 1901…an evening thunderstorm produced east winds to 43 mph with gusts to 48 mph.
 
In 1949…strong winds believed to be the worst in Boulder’s history at the time caused over 100 thousand dollars damage in the city.  Peak winds were estimated to 85 mph at Valmont…just east of Boulder.  High winds also occurred over most of metro Denver and caused damage to trees…window glass…and utility lines.  The damage was most pronounced over the northwest metro area…including north Denver and Lakewood.  Falling tree branches caused damage to parked autos and houses.  Wind gusts to 70 mph were recorded at Stapleton Airport.

In 1964…lightning struck and killed a 13-year-old boy…while he was riding his bicycle along a tree-lined residential street in south Denver.  Apparent microburst winds gusted to 54 mph at Stapleton International Airport.

Continue reading October 10 to October 16 – This week in Denver weather history

October 3 to October 9 – This week in Denver weather history

October 3 to October 9 - This week in Denver weather history
October 3 to October 9 - This week in Denver weather history

The first half of October historically is quiet for the most part but there have been years with plenty of excitement.  We have seen damaging tornadoes and winds and of course significant snowstorms.

From the National Weather Service:

In 1875…very dense haze hid the mountains from view as observed from the city.
 
In 1933…rainfall of just 0.01 inch was the only precipitation of the month.  This was the second driest October on record.
 
In 1954…the low temperature cooled to only 60 degrees…the all-time record high minimum for the month October.

3-4

In 1969…the first snowfall of the season totaled 16.0 inches at Stapleton International Airport.  There was a thunder snow shower on the evening of the 3rd…but otherwise little wind with the storm.  The greatest snow depth on the ground was 8 inches due to melting.  Heavy wet snow accumulated on trees…which were still in full leaf…and caused widespread damage from broken limbs and downed utility lines.

3-5

In 1984…the remnants of Pacific Hurricane Polo produced heavy rain over northeastern Colorado.  Most locations received between 1.00 to 2.50 inches of rain…but 3.45 inches fell in Littleton.  Rainfall totaled 1.73 inches at Stapleton International Airport…where north winds gusted to 24 mph.

In 1912…sustained south winds to 55 mph with gusts to 60 mph raised the temperature to a high of 83 degrees… The warmest temperature of the month that year.
 
In 1924…west winds were sustained to 46 mph with gusts to 50 mph in the city.  The apparent Bora winds cooled the temperature to a high of 57 degrees from a high of 70 degrees on the 3rd.
 
In 2004…several small tornadoes touched down near Brighton… Barr Lake…and Hudson in Adams and southern Weld counties. Most of these caused no damage.  However…a small tornado 5 miles southeast of Brighton caused extensive damage to a recreational vehicle and severely damaged a barn.  The barn was torn from its foundation…and the roof was thrown 100 feet.  Four llamas in the barn were injured when it collapsed.

4-5

In 1997…unusually warm weather resulted in two temperature records.  High temperature of 87 degrees on the 4th exceeded the old record set in 1922 by one degree.  High temperature of 86 degrees on the 5th equaled the record set in 1990 and previous years.

Continue reading October 3 to October 9 – This week in Denver weather history

September 26 to October 2 – This week in Denver weather history

September 26 to October 2 - This week in Denver weather history
September 26 to October 2 - This week in Denver weather history

Denver has been graced with an unusually mild September this year.  That however is not always the case and in fact the weather can be downright winterish as we see in our look back at this week in Denver weather history.

25-26

In 1908…apparent post-frontal rain changed to snow overnight and totaled 6.5 inches in downtown Denver.  This was the first snow of the season.  Precipitation totaled 0.76 inch. North winds were sustained to 39 mph on the 25th.

25-27

In 1996…an early season snowstorm brought heavy snow to the Front Range eastern foothills.  Snowfall totals included:  8 to 12 inches around conifer…7 inches on Floyd Hill…and 6 inches at both Bailey and Chief Hosa. Snowfall totaled only 4.7 inches at the site of the former Stapleton International Airport.  This was the first measurable snow of the season.  After the passage of a strong cold front…north winds gusted to 38 mph at Denver International Airport on the 25th.

26

In 1907…a late afternoon thunderstorm produced hail…0.23 inch of precipitation…and north winds sustained to 24 mph.
 
In 1927…snowfall of 1.7 inches…mixed at times with sleet… Was the first measurable snowfall of the season.
26-28

In 1936…the heaviest snowfall ever recorded in September and the heaviest snowfall ever recorded so early in the season dumped a total of 16.5 inches of snow on downtown Denver and 21.3 inches at Denver municipal airport.  The 15.0 inches of snow measured from 6:00 pm on the 27th to 6:00 pm on the 28th is the greatest 24 hour snowfall ever recorded in September.  This was the first snow of the season.  The snow was intermittent through the 26th…but continuous from early afternoon on the 27th to around midnight on the 28th…except for a period of rain during the afternoon of the 28th which contributed to a loss of depth on the ground.  The greatest snow depth on the ground downtown was 13 inches with 8 inches at Denver municipal airport.  There were no high winds with the storm and traffic was interrupted for only a short period.  The storm produced property damage estimated at 7 million dollars.  With trees and shrubs in full foliage…the leaves caught and held the heavy water-laden snow…until the branches snapped from the weight.  More than 3000 workmen were called to remove the debris and snow from the city.  The city firemen who were off duty…as well as all the reserves… Were asked to report to their stations.  All schools in the city remained open…but attendance was only 50 percent of normal.  Grade school students were sent home at noon on the 28th.  The early storm caught stockmen with many cattle still in higher ranges.  Warm weather followed the snow…which had all melted by the end of the month…except for a few inches in sheltered places.

Continue reading September 26 to October 2 – This week in Denver weather history

September 19 to September 25 – This week in Denver weather history

September 19 to September 25 - This week in Denver weather history
September 19 to September 25 - This week in Denver weather history

This time of year many folks would consider “snow” a bad four-letter word but living in the Mile High City we can’t rule it out even with it technically still being summer.  In fact, it was only 15 short years ago that we received a significant snowstorm that brought up to 8 inches of snow in the metro area and caused millions of dollars in damage. 

From the National Weather Service:

15-19

In 1906…rain on 5 consecutive days totaled 1.61 inches. A thunderstorm occurred on the 17th.  High temperatures ranged from 48 degrees on the 16th to 65 degrees on the 15th.  Low temperatures were in the lower to mid 40’s.

16-19

In 1971…a record breaking early fall snow storm caused extensive damage to trees and utility lines.  The heavy wet snow occurred with little wind…but caused record breaking cold temperatures for so early in the season.  Snowfall totaled 15.6 inches at Stapleton International Airport with most of the snowfall…12.0 inches…occurring on the 17th.  This was the heaviest first snow of the season. The maximum snow depth on the ground was 13 inches. Record low temperatures were set on three consecutive days: 31 degrees on the 17th…23 degrees on the 18th…and 20 degrees on the 19th…which was also a new all-time record minimum for the month at that time.  Record low maximum temperatures were set on 4 consecutive days:  48 degrees on the 16th…35 degrees on the 17th…40 degrees on the 18th… And 42 degrees on the 19th.

18-19

In 1955…heavy rains caused flash flooding across portions of metro Denver.  Rainfall totaled 1.71 inches at Stapleton Airport.

19

In 1955…hail stones to 2 1/2 inches in diameter were reported north of Denver.  The large stones broke many automobile windshields.
 
In 1963…hail to 3/4 inch in diameter fell in Westminster.
 
In 1983…an unusually strong cold front roared through metro Denver during the afternoon hours.  At Stapleton International Airport…the temperature dropped 51 degrees… From a sunny 86 degrees to a snowy 35 degrees…in just 7 hours.  Strong winds and a wall of blowing dust followed the front.  Northeast winds gusting to 36 mph briefly reduced the surface visibility to 1 mile in blowing dust at Stapleton International Airport where only a trace of snow fell later.
 
In 1996…high winds gusting to 84 mph were measured at Golden Gate Canyon in the foothills west of Denver. West winds gusted to only 25 mph at Denver International Airport.

Continue reading September 19 to September 25 – This week in Denver weather history

September 12 to September 18 – This week in Denver weather history

•September 12 to September 18 - This week in Denver weather history
•September 12 to September 18 - This week in Denver weather history

Normally one doesn’t associate tornadoes with September weather in Denver but they can and do happen as we see in our look back in Denver weather history for the week.  We have a couple of occasions of twisters and of a funnel cloud.  Other severe weather like hail, damaging wind and flooding rains have also occurred.   Oh, and should we mention the dreaded “S” word – snow?

11-12

In 1974…post-frontal rain changed to snow overnight for the first snow of the season.  Snowfall totaled only 1.8 inches at Stapleton International Airport where north winds gusted to 40 mph on the 11th.  High temperature of only 46 degrees on the 12th set a new record low maximum for the date.

12 

In 1887…west winds to 42 mph were recorded in the city.
 
In 1952…a thunderstorm outflow produced strong southeast winds gusting to 52 mph.  Surface visibility at Stapleton Airport was briefly reduced to 2 miles in blowing dust.
 
In 1963…a nearly stationary…white tornado near Bennett was sighted from Denver.  No damage was reported.
 
In 1989…an early snowfall and the first of the season brought 2 to 3 inches of slush to metro Denver.  More snow whitened the foothills west of Denver where 6 inches were measured at Evergreen.  The snow fell on leaf laden trees… And sagging branches onto power lines caused outages.  Much of Denver’s snow fell during the evening rush hour…creating traffic chaos.  Snowfall totaled 2.3 inches at Stapleton International Airport where the maximum snow depth on the ground was only 1 inch due to melting.
 
In 1994…thunderstorm microburst winds gusted to 67 mph in Boulder.  No damage was reported.
 
In 2002…a severe thunderstorm produced hail as large as 1 inch in diameter near Castle Rock.

Continue reading September 12 to September 18 – This week in Denver weather history

September 5 to September 11 – This week in Denver weather history

September 5 to September 11 - This week in Denver weather history
September 5 to September 11 - This week in Denver weather history

September is typically one of our quietest weather months and in fact it is our sunniest.  That doesn’t however mean we can’t experience weather extremes.  This week in Denver weather history we see everything from scorching heat and severe thunderstorms to snow and damaging wind.  For more about September’s weather, check out our September weather preview.

1-5

In 1995…record breaking heat occurred on the first 5 days of the month when the temperature climbed into the 90’s on each day.  Record high temperatures of 97 degrees on both the 1st and 4th equaled the all-time record maximum for the month.  High temperature of 95 degrees on the 3rd was a record for the date.  High temperatures of 94 degrees on both the 2nd and the 5th were not records.  The low temperature of 64 degrees on the 4th equaled the record high minimum for the date.

1-7

In 1978…the temperature reached 90 degrees or more on seven consecutive days with the highest temperature…94 degrees… Recorded on both the 4th and 6th.

3-6

In 1909…rainfall for the 4 days accumulated to 3.97 inches in Boulder…while in Denver rainfall totaled 2.45 inches on the 4th…5th…and 6th.

5  

In 1899…the highest recorded temperature in September…97 degrees…occurred.  The same temperature was also reached on September 4…1960…and September 1 and 4…1995.
 
In 1940…a severe wind and hail storm confined mostly to the west and north parts of the city occurred shortly after 4:30 pm.  Hail stones ranged in size from 1/4 to 1/2 inch in diameter. In north Denver…hail piled to a depth of 4 inches.  Flooding occurred in one underpass…which stalled 2 cars.  One girl was injured when the weight of the hail flattened a porch on which she stood. Northeast winds were sustained to 29 mph with gusts to 32 mph in downtown Denver.
 
In 1987…a thunderstorm complex produced hail as large as 1 3/8 inches in diameter…2 miles east of Buckley Field in Aurora.  No damage was reported.

Continue reading September 5 to September 11 – This week in Denver weather history