Wildlife is still quite active along the Front Range and flowers will hold on to their petals for at least the first part of the month. Then of course there is the weather which you never know what to expect. Thunderstorms, heavy rain, and even snow are a possibility.
Slideshow updated October 4, 2016
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=”72157670754216514″]
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.
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September 25 to October 1: This week in Denver weather history
Colorado’s famously inconsistent weather can be seen in our look back at this week in Denver weather history. Not only do we see damaging thunderstorms and winds but even major snowstorms that deposited more than a foot of the white stuff on the city.
From the National Weather Service:
25
In 1873…a fire was sighted in the woods near Platte Canyon… Probably caused by high winds blowing sparks among the timber.
In 1896…an apparent cold front produced northeast sustained winds to 40 mph with gusts to 48 mph.
In 1910…a thunderstorm produced sustained north winds to 51 mph. This was the highest recorded wind speed in the city in September at the time.
In 1936…a vigorous cold front produced a deadly dust storm in the city. North winds sustained to 36 mph with gusts to 38 mph produced much blowing dense dust…greatly restricting the visibility. The temperature plunged from a high of 84 degrees to a low of 38 degrees by midnight. The weather observer described the event with the following. “at 6:00 pm the temperature was 82 degrees and the wind velocity was only 4 mph; but with the wind shifting to the north and the barometer rising quite rapidly…the temperature fell sharply. By 6:30 pm…the wind velocity increased rapidly and by 7:00 pm had reached a maximum sustained velocity of 36 mph…bringing with it clouds of dust which had been picked up by gale force winds in southern Wyoming and northern Colorado…covering the city. The visibility was generally reduced to about 1/4 mile; however…the whirling of the dust down the streets and alleys…the visibility was at times somewhat less. Airplanes were grounded…traffic was halted at times…and homes filled with dust. The strong winds damaged electric power and telephone lines…leaving homes in darkness for a few hours in the city and for 18 hours in suburban towns and putting 2500 telephones out of service because of broken lines. An electric lineman was killed while repairing damage by the high winds. The dust storm was followed by rain that began falling at 10:55 pm…which turned to snow during the early morning hours of the 26th. A major snow storm followed on the 27th through the 29th.”
In 1999…high winds developed in the foothills of Boulder County. Winds gusted to 90 mph at Wondervu.
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.
In 2012…a man was seriously injured when he was struck by lightning outside the Hebrew Educational Alliance as he and his family were getting in their car. The victim stopped breathing but was saved when his wife performed cardiopulmonary resuscitation on him immediately.
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.
27
In 1877…smoke from heavy forest fires in the mountains spread over the city on upper wind currents.
In 1935…the first snow of the season was 2.8 inches in downtown Denver. The low temperature dipped to 31 degrees for the first freeze of the season.
September 18 to September 24: This week in Denver weather history
The calendar may still say it is summer for a few more days but our look back at this week in Denver weather history shows that Old Man Winter can still make an appearance.
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
In 1901…northeast winds were sustained to 42 mph with gusts to 50 mph behind an apparent cold front.
In 1948…the low temperature cooled to only 69 degrees…the all-time record high minimum for the month.
In 1988…a strong cold front blasted metro Denver with high winds. Gusts reached 82 mph in Longmont and 81 mph at Jefferson County Airport near Broomfield where the winds flipped over and destroyed a small airplane. Wind gusts to 60 mph were recorded in Boulder and Wheat Ridge. West wind gusts to 54 mph were clocked at Stapleton International Airport. The strong winds downed trees and power lines and damaged homes and cars. A Longmont man was slightly injured…when a tree fell on top of his car.
In 1990…a slow moving thunderstorm over southwest metro Denver spawned an ominous looking funnel cloud near the intersection of Sheridan Blvd. and U.S. Highway 285. The funnel cloud nearly touched down a few times before lifting back into the main cloud. No damage was reported. Pea to marble size hail and 3/4 inch of rain fell over central and northeast Denver. Numerous streets and underpasses became flooded on Denver’s south side when the heavy runoff backed up storm sewers. Thunderstorm rainfall totaled 1.02 inches at Stapleton International Airport.
In 1993…a severe thunderstorm rolled through southeast metro Denver. Dime size hail was reported in many areas. Straight-line winds from the thunderstorm…measured by a weather spotter at 70 mph…tore the roof off 6 apartments of an apartment complex in Aurora. Heavy rain which accompanied the winds caused major damage to the apartments as well as the contents. Many trees…fences… And power poles were knocked down by the strong winds. Heavy rain flooded roadways in Denver and Aurora. Thunderstorm rainfall totaled 1.08 inches and north winds gusted to 44 mph at Stapleton International Airport where the visibility was briefly reduced to as low as 1/4 mile in heavy rain.
In 1996…a late summer snowstorm struck the northern mountains and Front Range eastern foothills. Golden Gate Canyon received 6 inches of new snow with 5 inches reported at both Nederland and Blackhawk. Thunderstorms produced heavy rain across metro Denver…which was mixed with snow by late evening. Rainfall totaled 0.83 inch at the site of the former Stapleton International Airport and 1.22 inches at Denver International Airport where northwest winds gusted to 39 mph.
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.
September 11 to September 17: This Week in Denver Weather History
Severe weather is less common as we enter the fall season but it is not entirely unheard of. As we see in our look back at this week in Denver weather history, we have seen everything ranging from torrential rains to tornadoes and even heavy snow.
11
In 1910…west winds were sustained to 42 mph.
In 1951…a vigorous Canadian cold front produced a dust storm across metro Denver. Northeast wind gusts to 43 mph reduced the visibility at Stapleton Airport to as low as 1 1/2 miles for nearly 5 hours. The temperature dropped 47 degrees in 8 hours…from a high of 92 degrees to a low of 45 degrees.
In 1967…a microburst wind gust to 52 mph produced blowing dust and briefly reduced the visibility to 1/2 mile at Stapleton International Airport.
In 1974…a trace of snow…the first of the season…ended the shortest period without snow…94 days from June 9th through September 10th. A trace of snow also fell on June 8th.
In 1995…strong post-frontal winds associated with a fast moving pacific cold front knocked down power poles and trees as it moved through metro Denver. Numerous power outages affected nearly one thousand people in Denver and Jefferson counties. West winds gusted to 34 mph at Denver International Airport.
11-16
In 2013…a deep southerly flow over Colorado… Ahead of a nearly stationary low pressure system over the great basin… Pumped copious amounts of monsoonal moisture into the area. In addition…a weak stationary front stretched along the Front Range foothills and Palmer Divide. This resulted in a prolonged period of moderate to heavy rain across the Front Range foothills…Palmer Divide…urban corridor. By the 14th…storm totals ranged from 6 to 18 inches… Highest in the foothills of Boulder County. The headwaters then moved down the South Platte River and caused widespread flooding with record flood stages at several locations as it made its way downstream. The record high flood stages resulted in widespread flooding along the South Platte River basin. The flood damage encompassed 4500 square miles of the Front Range…left 7 dead… Forced thousands to evacuate…and destroyed thousands of homes and farms. Record amounts of rainfall generated flash floods that tore up roads and lines of communication… Leaving many stranded. Nearly 19000 homes were damaged… And over 1500 destroyed. Colorado department of transportation estimated at least 30 state highway bridges were destroyed and an additional 20 seriously damaged. Preliminary assessments of the state`s infrastructure showed damage of $40 million to roads and $112 million to bridges. Repair costs for state and county roads ran into the hundreds of millions of dollars. Miles of freight and passenger rail lines were washed out or submerged… Including a section servicing Amtrak`s iconic California Zephyr. The town of Lyons was isolated by the flooding of St. Vrain creek…and several earth dams along the Front Range burst or were over-topped. Floodwaters swept through Estes Park; damaged hundreds of buildings and destroyed large sections of U.S. 34 from Loveland and U.S. 36 from Lyons to Boulder. U.S. 34 suffered the most damage… With 85 percent of its roadway and bridges destroyed. In Weld County…about nearly two thousand gas wells were damaged and had to be closed off as the floodwaters inundated entire communities. Sewage treatment plants and other utilities were knocked out in a number of towns. Governor Hickenlooper declared a disaster emergency on September 13th…in 11 counties across northeast Colorado including: Adams…Arapahoe…Broomfield…Boulder…Denver… Jefferson…Larimer…Logan…Morgan… Washington and Weld. By the 15th…federal emergency declarations covered those counties as well as Clear Creek County. Projected losses from the flooding statewide was nearly two billion dollars in property damage…according to Eqecat… A catastrophe modeling firm. The damage was most severe in and around Lyons and Boulder. More than 11 thousand people were evacuated…reportedly the largest since Hurricane Katrina. President Obama declared a state of emergency for Boulder and Larimer counties. An additional 10 counties were added on the 16th and included: Adams… Arapahoe…Broomfield…Clear Creek…Denver…Jefferson… Morgan…Logan… Washington and Weld counties. The president also declared a major disaster specifically for Boulder County. There were six fatalities directly attributed to flash flooding. Two 19-yr old teenagers died on the 11th…after they were swept away by floodwaters after abandoning their car on Lindon Drive in Boulder. In Jamestown…a 72-yr old man was killed when the building he was in collapsed. An 80-yr old Lyons resident died in the early morning hours of the 12th…when his truck was swept into the St. Vrain River near his home. Later on the 12th…a 79-yr old Larimer County resident was killed when she was swept away while trying to climb to safety from her home in Cedar Point. A 61-yr old cedar point resident died when her home was swept down the Big Thompson River by the floodwaters. An 80-yr old Idaho Springs resident drowned in Clear Creek when the embankment he was standing on collapsed. In Boulder…some of the monthly records broken included: one-day all-time record: 9.08 inches which shattered the previous wettest day of 4.8 inches set on July 31… 1919; one-month record of 18.16 inches…which broke the previous all-time monthly record of 9.59 inches set in May of 1995; wettest September on record which broke the previous record of 5.5 inches set in September of 1940; one-year record of 34.15 inches broke the previous wettest year of 29.93 inches set in 1995. At Denver International Airport…the total precipitation for the month of September was 5.61 inches…which was 4.65 inches above the normal of 0.96 inches. This is the most precipitation ever recorded in Denver for the month of September. Daily precipitation records included 1.11 inches on the 12th and 2.01 inches on the 14th.
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.
Our August weather was a bit of a mixed bag by the two biggest standards. On one hand, it was cooler than normal which was nice. On the other, we saw less than half the amount of precipitation we normally see during August.
August typically is when the monsoon kicks in and we see healthy doses of precipitation. This year however, the monsoonal flow was regularly disrupted by troughs digging in from the north and west.
August 2016 top shots: Monthly photo slideshow
We certainly started the month hot with three days of temperatures near or above 95 degrees. Things then cooled down for a few days as the first trough moved through. Warmer temperatures then returned with readings not too far off of normal for the next two weeks. The final 10 days or so of the month then saw cooler conditions with the majority of days recording readings below normal.
Thornton’s overall average temperature for the month came in at 69.5 degrees. That was three degrees cooler than Denver’s long term average of 72.5 degrees. Out at the airport where Denver’s official measurements are taken, the airport split the difference with an average of 71.2 degrees.
Temperature ranged from a high of 97.2 degrees on the third of the month down to a cool 46.7 degrees on the 25th. Denver saw a maximum of 97 degrees on the 9th and a low of 47 degrees on the 25th. Thornton saw 14 days with highs at or above 90 degrees while Denver recorded 15.
Officially, one temperature record was made. On the morning of the 27th the mercury at DIA dropped to 48 degrees typing the record low for the date.
In terms of precipitation, Denver averages 1.69 inches during the month of August. Thornton saw only 0.76 inches in our rain bucket. The airport fared even worse with only 0.22 inches making the month the eight driest August on record in Denver.
Thornton, Colorado’s August 2016 temperature summary. (ThorntonWeather.com)Thornton, Colorado’s August 2016 precipitation summary. (ThorntonWeather.com)
From the National Weather Service:
CLIMATE REPORT
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
848 AM MDT THU SEP 1 2016
...................................
...THE DENVER CO CLIMATE SUMMARY FOR THE MONTH OF AUGUST 2016...
CLIMATE NORMAL PERIOD 1981 TO 2010
CLIMATE RECORD PERIOD 1872 TO 2016
WEATHER OBSERVED NORMAL DEPART LAST YEAR`S
VALUE DATE(S) VALUE FROM VALUE DATE(S)
NORMAL
................................................................
TEMPERATURE (F)
RECORD
HIGH 105 08/08/1878
LOW 40 08/26/1910
08/25/1910
08/24/1910
HIGHEST 97 08/09 98 08/15
LOWEST 47 08/25 43 08/23
08/20
AVG. MAXIMUM 86.3 87.2 -0.9 89.8
AVG. MINIMUM 56.2 57.9 -1.7 58.3
MEAN 71.2 72.5 -1.3 74.0
DAYS MAX >= 90 15 11.5 3.5 19
DAYS MAX <= 32 0 0.0 0.0 0
DAYS MIN <= 32 0 0.0 0.0 0
DAYS MIN <= 0 0 0.0 0.0 0
PRECIPITATION (INCHES)
RECORD
MAXIMUM 5.85 1979
MINIMUM 0.02 1924
TOTALS 0.22 1.69 -1.47 1.18
DAILY AVG. 0.01 0.05 -0.04 0.04
DAYS >= .01 4 8.6 -4.6 9
DAYS >= .10 1 4.3 -3.3 4
DAYS >= .50 0 1.2 -1.2 1
DAYS >= 1.00 0 0.3 -0.3 0
GREATEST
24 HR. TOTAL 0.12 08/24 TO 08/24 08/11 TO 08/11
08/10 TO 08/11
DEGREE_DAYS
HEATING TOTAL 15 10 5 13
SINCE 7/1 15 16 -1 18
COOLING TOTAL 218 244 -26 304
SINCE 1/1 762 688 74 713
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 2/173
HIGHEST WIND SPEED/DIRECTION 43/010 DATE 08/19
HIGHEST GUST SPEED/DIRECTION 55/020 DATE 08/19
SKY COVER
POSSIBLE SUNSHINE (PERCENT) MM
AVERAGE SKY COVER 0.60
NUMBER OF DAYS FAIR 4
NUMBER OF DAYS PC 22
NUMBER OF DAYS CLOUDY 5
AVERAGE RH (PERCENT) 47
WEATHER CONDITIONS. NUMBER OF DAYS WITH
THUNDERSTORM 11 MIXED PRECIP 0
HEAVY RAIN 0 RAIN 1
LIGHT RAIN 10 FREEZING RAIN 0
LT FREEZING RAIN 0 HAIL 0
HEAVY SNOW 0 SNOW 0
LIGHT SNOW 0 SLEET 0
FOG 5 FOG W/VIS <= 1/4 MILE 3
HAZE 4
- INDICATES NEGATIVE NUMBERS.
R INDICATES RECORD WAS SET OR TIED.
MM INDICATES DATA IS MISSING.
T INDICATES TRACE AMOUNT.
Following on what was a cool but dry August, some are certainly hoping for a bit of precipitation. The month can bring plenty of rain and even our first snow of the season but more often than not, it is one of the most pleasant along the Colorado Front Range.
As temperatures start to drop, September usually reminds us that summer is at an end and fall is now here. Sunshine is predominant though as the month actually has the highest percentage of sun out of any month. Sunny days and clear, cool nights are the standard weather pattern for the month.
The month can bring extremes however. We will of course forever remember last year’s devastating floods brought on by record-setting rain. Longtime residents might remember September 1971 which brought over 17 inches of snowfall.
September 4 to September 10: This Week in Denver Weather History
The first full week of September sees us start one of the most pleasant times of year in Denver. While less common this time year, severe weather can and does occur. Our look back at this week in Denver weather history includes hail, damaging wind and even smoke from wildfires hundreds of miles away.
From the National Weather Service
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.
4
In 1909…apparent post-frontal heavy rainfall totaled 1.94 inches in downtown Denver. North winds were sustained to 19 mph.
In 1944…a trace of rain fell. This together with a trace of rain on the 9th…10th…and 30th was the only precipitation for the month. The total of a trace of precipitation for the month equaled the driest September on record first set in 1892.
In 1960…the highest recorded temperature in September…97 degrees…occurred. The same temperature also occurred on September 5…1899…September 1…1995…and September 4… 1995.
In 1989…a strong thunderstorm wind gust flipped a plane taxiing on a private runway in Adams County east of Denver. Two people were slightly injured and the plane was heavily damaged.
In 1992…strong winds developed across metro Denver behind a pacific cold front. Sustained winds above 40 mph with gusts as high as 60 mph were recorded mainly in and near the foothills. Pre-frontal south winds gusted to 37 mph at Stapleton International Airport.
In 1995…two people were injured when lightning struck their home in Lakewood. The lightning entered the attic where it started a small fire. It then traveled through the walls… Exploding a mirror and spraying glass on the residents. Lightning also sparked small grass fires near Aurora…Denver International Airport…and Bennett. The highest recorded temperature in September…97 degrees…occurred. The same temperature also occurred on September 5…1899…September 4…1960…and September 1…1995.
In 2000…thunderstorm winds gusted to 64 mph in Castle Rock.
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.
5-9
In 1988…layers of smoke aloft from large forest fires in Yellowstone National Park completely obliterated the sun at times. At Stapleton International Airport…surface visibility was reduced at times to 5 and 6 miles in smoke.
6
In 1940…a thunderstorm pelted the city with small hail. The storm produced some lightning damage. One woman was stunned by a bolt which struck near her. Heavy rain from the storm raised the level of Cherry Creek by more than 3 feet during the height of the storm. Rainfall downtown was only 0.26 inch.
In 1988…strong winds blew down two houses that were under construction in Castle Rock. Northwest winds gusted to 44 mph at Stapleton International Airport.
In 1993…a man was struck and killed by lightning while standing outside his home in unincorporated Arapahoe County 11 miles south of Denver. Lightning also struck a cabin in Marshdale…20 miles southwest of Denver…which started a fire and damaged one room and a portion of the roof.
In 1995…hail as large as 3/4 inch in diameter fell in Coal Creek Canyon in northern Jefferson County.
In 2001…a thunderstorm dropped 3/4 inch diameter hail in Aurora near Cherry Creek.
7
In 1875…the creeks were running dangerously high during the night from heavy rains in the mountains.
In 1885…a thunderstorm produced very white hail of irregular shape and about the size of beans. Precipitation was only 0.10 inch.
In 1971…a vigorous cold front accompanied by a thunderstorm produced wind gusts to 48 mph at Stapleton International Airport and much upslope cloudiness and light rain across metro Denver.
In 1989…widespread thunderstorms produced lightning strikes that knocked out power to about 13 thousand homes in Boulder County. In a rugged area stripped of vegetation by a forest fire earlier in July…heavy rain triggered mud slides that destroyed one home and severely damaged another in Boulder Canyon 10 miles west of Boulder. In one home…the mud caved in an exterior wall and poured into the residence only seconds after 2 people had evacuated the premises. Rainfall totaled 1 to 3 inches. Hail 1 3/4 inches in diameter fell in Nederland…Idaho Springs…and Golden Gate Canyon. Hail 1 inch in diameter was measured 10 miles north of Golden.
In 1993…thunderstorm winds toppled an overhead sign onto the intersection of I-70 and I-25 in Denver…causing considerable damage to 4 vehicles. The winds also caused a police car to be blown off the road northeast of Denver. Thunderstorm winds gusting to 66 mph damaged the siding of a residence southeast of Brighton. A thunderstorm wind gust to 53 mph was recorded at Stapleton International Airport. Hail to 7/8 inch in diameter fell at Kittredge in the foothills of Jefferson County.
In 1994…lightning severely damaged a public television transmitter atop Squaw Mountain west of Denver.
August 28 to September 3: This Week in Denver Weather History
So who is ready for some snow? Along with many other notable weather events, it was this week in Denver history when we received our earliest snowfall on record!
From the National Weather Service:
19-30
In 1875…grasshoppers appeared in great numbers at 10:00 am on the 19th. Thousands landed on the ground. The streets were literally covered with them. Swarms of grasshoppers were seen on each day. All gardens in the city were devastated…and in the countryside the grasshoppers were very destructive to ripened grain. On the 30th the grasshoppers were so numerous as to almost darken the sun.
27-28
In 2004…a brief chilly spell resulted in three temperature records. The high temperature of 55 degrees on the 27th was a record low maximum for the date. The low temperature of 48 degrees on the 27th equaled the record minimum for the date. The low temperature of 42 degrees on the 28th was a record minimum for the date.
28
In 1887…a dry thunderstorm produced north winds to 48 mph but only a trace of rainfall.
In 1968…one man was seriously injured by lightning while riding on a roller coaster at a Denver amusement park. An airline employee was injured when lightning struck a jetliner he was servicing at Stapleton International Airport. A lightning-caused fire did extensive damage to one house and minor damage to several others in the city of Denver.
In 1970…a microburst wind gust to 53 mph was recorded at Stapleton International Airport.
In 2002…a severe thunderstorm produced 3/4 inch diameter hail near Parker.
In 2005…lightning sparked a small fire near Jamestown. The blaze was quickly contained and consumed less than an acre.
29
In 1876…after the passage of a gentle rain shower to the east during the late evening hours…the moon shone brightly and a remarkably bright lunar rainbow appeared.
In 1910…an apparent cold front produced sustained northeast winds to 40 mph.
In 1946…the high temperature warmed to only 55 degrees…the record low maximum for the month.
In 1989…a spectacular lightning display knocked out power to 300 blocks in southeast Denver. One bolt started a fire in a lumber yard in the northeast part of the city…and the attic of a home in the same area was set ablaze by a lightning bolt.
In 1996…3/4 inch diameter hail was measured in Parker.
In 2000…lightning struck two homes in Thornton. The extent of damage was unknown.
In 2002…two small tornadoes caused damage in southeast metro Denver. The first tornado…associated with a multi-vortex storm…touched down briefly near E-470 and South Jordan Road. Some fences were damaged…and a few trees were blown down. A few of the homes also sustained minor roof damage. Damage from this storm totaled 100 thousand dollars. The second tornado associated with the storm touched down in a subdivision that was under construction at Gartrell and Arapahoe roads. Four large condominiums under construction were destroyed. The most heavily damaged portions of the structures were still in the framing stages. Adjacent sections where enclosed walls were in place were not destroyed. A man suffered 4 broken ribs and several cuts and bruises when the trailer he sought shelter in was flipped three times and torn apart by the twister. Damage from this storm totaled 6 million dollars. A severe thunderstorm produced 1 inch diameter hail near Evergreen.
In 2006…severe thunderstorms produced large hail in the foothills west of Denver. Hail to 1 inch in diameter fell near Blackhawk. Hail as large as 7/8 inch was measured near Idaho Springs…along with 3/4 inch hail near Nederland and conifer.
30
In 1981…60 mph winds were reported in Boulder.
In 2004…a severe thunderstorm produced hail as large as 1 inch in diameter in south Aurora near Cherry Creek.
31
In 1951…hail as large as 1 3/4 inches in diameter caused an estimated 300 thousand dollars damage in metro Denver. Hail as large as 1 1/2 inches in diameter was measured at Stapleton Airport.
In 1978…strong thunderstorm winds tore the roof off an apartment building in Aurora…downed trees…and damaged windows in Denver. A microburst wind gust to 58 mph was recorded at Stapleton International Airport.
In 1985…a thunderstorm wind gust to 60 mph was clocked at Buckley Field in Aurora.
In 1997…hail to 1 1/4 inches in diameter was measured in Aurora.
In 2006…a female postal worker was struck and injured by lightning while delivering mail in Westminster.
In 2008…lightning struck a home in Brighton…damaging the roof and a bedroom. The damaged totaled 20 thousand dollars.
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In 1951…large hail pounded Boulder…causing thousands of dollars in damage to roofs and automobiles. Heavy thunderstorm rainfall flooded basements and produced widespread street flooding.
In 1966…severe thunderstorms caused local flooding in areas from Denver to the north and east. There was scattered damage from hail and lightning. Streets were flooded in Boulder…and streets and basements were flooded in several areas of metro Denver. The public reported 1 inch diameter hail in Aurora and near Cheery Creek Reservoir. Thunderstorm rainfall totaled only 0.39 inch at Stapleton International Airport.
In 1985…severe thunderstorms dumped heavy rain and hail at many locations along the Front Range from Denver south. The southern and eastern suburbs of metro Denver were especially hard hit. Rainfall from 1 1/2 to 3 inches caused extensive street flooding in Aurora where two creeks rose out of their banks. Two homes in the city suffered minor lightning damage. Almost 4 inches of rain fell in the Parker area. Hail up to ping-pong ball size piled up to a foot deep and closed a road in Evergreen. Hail as large as 1 3/4 inches in diameter was reported 8 miles northeast of Deckers. Wind gusts to 65 mph were estimated in southeast Aurora.
In 1990…marble size hail piled up to 2 inches deep in the foothills community of Kittredge…18 miles southwest of Denver. As much as half an inch of rain fell in just 15 minutes and caused minor road and small stream flooding. A thunderstorm dropped pea to marble size hail and brief heavy rain near Ward road and 64th avenue in Arvada. Minor street and small stream flooding was reported in the area.
In 1995…a strong thunderstorm microburst with only a few drops of rain produced a recorded wind gust to 85 mph at the site of the former Stapleton International Airport. The wind gust occurred at 8:30 pm MDT. The all-time highest recorded temperature in September…97 degrees… Occurred. The same temperature also occurred on September 5…1899…September 4…1960…and September 4… 1995.
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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.
With the mercury stuck stubbornly at the top of the scale and barely a few raindrops falling into the bucket, September 2015 will be going into the books as one of the warmest and driest on record.
High pressure dominated the entire region during the month. This allowed temperatures to consistently climb above normal and helped prevent moisture from arriving in any significant amounts. At Denver International Airport, 27 of the 30 days had above normal temperatures. Thornton’s overall temperatures were cooler than DIA’s but we were still quite a bit warmer than average.
The monthly average temperature in Thornton came in at 67.1 degrees. Out at the airport where the Mile High City’s official measurements are taken, the average was 69.4 degrees.
Denver’s historical average for September is 63.4 so both locations came in well above normal. Officially, September 2015 ranks as the warmest September on record, easily jumping to the number one spot over September 1948 which had an average of 68.3 degrees.
Undoubtedly the big difference between measurements at DIA and other locations in the metro area are yet another example of the airport’s readings consistently being an outlier from the reality seen in more populated areas. This has been an ongoing problem since the National Weather Service moved the official station from Stapleton.
The warmest mercury reading in Thornton during the month was 94 degrees on the 13th. The coldest came on the 19th when temperatures dipped to 40 degrees in the early morning hours. Eight days in Thornton topped out above the 90 degree mark.
At the airport, Denver’s warmest reading of 92 degrees came on September 2. It’s coldest on September 19 (44 degrees). The airport saw seven days with above 90 degree maximums.
Just as the month was exceedingly warm, it also was very dry. Thornton saw a mere 0.09 inches fall in its rain bucket and Denver recorded 0.11 inches. Both were far short of the September precipitation average of 0.96 inches.
DIA’s measurement means September 2015 goes into the books with the 9th least amount of precipitation in September since 1872 (16th driest overall).
Thornton, Colorado’s September 2015 temperature summary. (ThorntonWeather.com)Thornton, Colorado’s September 2015 precipitation summary. (ThorntonWeather.com)
From the National Weather Service:
CLIMATE REPORT
NATIONAL WEATHER SERVICE BOULDER, CO
244 AM MDT THU OCT 1 2015
...THE DENVER CO CLIMATE SUMMARY FOR THE MONTH OF SEPTEMBER 2015...
CLIMATE NORMAL PERIOD 1981 TO 2010
CLIMATE RECORD PERIOD 1872 TO 2015
WEATHER OBSERVED NORMAL DEPART LAST YEAR`S
VALUE DATE(S) VALUE FROM VALUE DATE(S)
NORMAL
................................................................
TEMPERATURE (F)
RECORD
HIGH 97 09/06/2013
09/05/2013
09/04/1995
LOW 17 09/29/1985
HIGHEST 92 09/02 91 1 94 09/03
LOWEST 44 09/19 35 9 33 09/12
AVG. MAXIMUM 85.2 78.5 6.7 78.9
AVG. MINIMUM 53.5 48.3 5.2 50.6
MEAN 69.4 63.4 6.0 64.8
DAYS MAX >= 90 7 3.4 3.6 2
DAYS MAX <= 32 0 0.0 0.0 0
DAYS MIN <= 32 0 0.8 -0.8 0
DAYS MIN <= 0 0 0.0 0.0 0
PRECIPITATION (INCHES)
RECORD
MAXIMUM 5.61 2013
MINIMUM T 1892 1944
TOTALS 0.11 0.96 -0.85 1.79
DAILY AVG. 0.00 0.03 -0.03 0.06
DAYS >= .01 3 6.5 -3.5 9
DAYS >= .10 0 3.3 -3.3 4
DAYS >= .50 0 0.6 -0.6 1
DAYS >= 1.00 0 0.1 -0.1 1
GREATEST
24 HR. TOTAL 0.12 08/31 TO 09/01 09/29 TO 09/29
09/28 TO 09/29
09/29 TO 09/29
STORM TOTAL MM MM
(MM/DD(HH)) MM 09/29(00) TO 09/29(00)
09/29(00) TO 09/29(00)9
09/29(00) TO 09/29(00)9
SNOWFALL (INCHES)
RECORDS
TOTAL MM MM
TOTALS 0.0 1.3
DEGREE_DAYS
HEATING TOTAL 9 125 -116 91
SINCE 7/1 27 141 -114 98
COOLING TOTAL 148 76 72 88
SINCE 1/1 861 764 97 701
FREEZE DATES
RECORD
EARLIEST 09/08/1962
LATEST 06/08/2007
EARLIEST 10/07
LATEST 05/05
..........................................................
WIND (MPH)
AVERAGE WIND SPEED 9.0
RESULTANT WIND SPEED/DIRECTION 2/195
HIGHEST WIND SPEED/DIRECTION 35/280 DATE 09/07
HIGHEST GUST SPEED/DIRECTION 54/270 DATE 09/07
SKY COVER
POSSIBLE SUNSHINE (PERCENT) MM
AVERAGE SKY COVER 0.40
NUMBER OF DAYS FAIR 12
NUMBER OF DAYS PC 17
NUMBER OF DAYS CLOUDY 1
AVERAGE RH (PERCENT) 41
WEATHER CONDITIONS. NUMBER OF DAYS WITH
THUNDERSTORM 6 MIXED PRECIP 0
HEAVY RAIN 0 RAIN 3
LIGHT RAIN 7 FREEZING RAIN 0
LT FREEZING RAIN 0 HAIL 3
HEAVY SNOW 0 SNOW 0
LIGHT SNOW 0 SLEET 0
FOG 3 FOG W/VIS <= 1/4 MILE 5
HAZE 1
- INDICATES NEGATIVE NUMBERS.
R INDICATES RECORD WAS SET OR TIED.
MM INDICATES DATA IS MISSING.
T INDICATES TRACE AMOUNT.
September 27 to October 3: This week in Denver weather history
With the end of summer and the arrival of fall, looking back at Denver weather history we start to see more mentions of snow. It is of course not the only notable weather event this time of year. We still have received severe thunderstorms, damaging winds, and 90 degree plus heat.
From the National Weather Service:
From the 25th to the 27th:
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.
From the 26th to the 28th:
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.
On the 27th:
In 1877…smoke from heavy forest fires in the mountains spread over the city on upper wind currents.
In 1935…the first snow of the season was 2.8 inches in downtown Denver. The low temperature dipped to 31 degrees for the first freeze of the season.
From the 27th to the 28th:
In 1984…heavy snow fell over the plains and foothills. Snowfall amounts ranged from 2 to 5 inches on the plains with up to a foot at higher elevations in the foothills. The main problem caused by the storm was thousands of power outages caused by snow-laden tree limbs snapping and falling onto power lines. Over 15 thousand homes lost power in metro Denver. Some cars were damaged by falling trees and limbs. The snow also caused some flight delays at Stapleton International Airport where 5.1 inches of snow fell and northeast winds gusted to 29 mph. Maximum snow depth on the ground was 3 inches due to melting. The high temperature of only 34 degrees on the 28th was a record low maximum for the date and equaled the all-time record for the month at that time.
On the 28th:
In 1877…heavy dense smoke from mountain forest fires spread over the city. The smoke was so dense that it obscured the sun at times.
In 1921…post-frontal northeast winds were sustained to 44 mph.
In 1953…a pacific cold front produced a west wind gust to 59 mph at Stapleton Airport where the visibility was briefly reduced to 3/4 miles in blowing dust. Strong winds were also widespread over Boulder during the afternoon.
In 1960…strong…gusty winds tore the roof from 6 units of a motel on west Colfax Avenue in Denver. The roofing sailed over the building and crashed down on a truck…wrecking it. The strong winds were the result of an apparent microburst.
In 1999…snow fell in the foothills west of metro Denver and over the plains. Snowfall totals included 7 inches at Conifer. At the site of the former Stapleton International Airport…3.1 inches of snow were measured. This was the first snow of the season. The heavy wet snow snapped branches from fully leafed trees…downing power lines and causing scattered outages.
In 2004…severe thunderstorms produced hail to 3/4 inch in diameter in Littleton and in Douglas County 14 miles northwest of Castle Rock.
In 2012…a weak tornado (ef-0) tornado touched down near Strasburg. No damage was reported.
From the 28th to the 29th:
In 1959…one of the heaviest September snow storms of record began as rain and changed to heavy wet snow. The storm caused heavy damage to trees and shrubbery…which were still in full leaf. The storm dumped 10.6 inches of snow at Stapleton Airport…the third heaviest September snow amount to date. Falling trees and limbs disrupted traffic…broke power and communication lines…and damaged buildings and cars. One man was killed in Denver by a falling tree limb…and four others died of heart attacks while shoveling snow or trying to move heavy tree limbs. Direct costs of the storm for cleaning up debris…repairing utility lines…and damage to buildings and other property across all of eastern Colorado were estimated to be over a half million dollars. The value of trees destroyed or damaged was estimated to exceed five million dollars. North-northeast winds gusted to 32 mph at Stapleton Airport on the 28th.
In 1985…an unusually cold air mass for this time of year settled over the area. Metro Denver received 8 to 12 inches of powdery snow. The 8.7 inches of snow that fell at Stapleton International Airport was the first measurable snow of the season and the city’s heaviest September snowfall since 1971. The snow caused flight delays of over 2 hours at Stapleton International Airport. I-70 was closed for a time west of Denver. Snow-laden tree limbs snapped over all of metro Denver…causing widespread power outages. Ten thousand people were without electricity for a time in Boulder. The morning of the 29th saw mid-winter temperatures along the Front Range. The temperature dipped to 17 degrees…the lowest temperature ever recorded in September in Denver. The high temperature of only 29 degrees on the 29th was a new record low maximum for the date and lowest ever recorded during the month of September. The low temperature of 21 degrees on the evening of the 28th set a new record low for the date. The cold weather persisted through the 1st with record minimum temperatures of 25 degrees set on the 30th and 27 degrees set on October 1st.
On the 29th:
In 1966…a vigorous cold front moved thru metro Denver. North winds gusting to 51 mph kicked up billows of blowing dust…which briefly reduced the visibility to 1 mile at Stapleton International Airport. The cold air caused temperatures to drop rapidly from a high of 86 degrees to a low of 46 degrees by days end.
In 1985…the lowest temperature ever recorded in September… 17 degrees…occurred. The high temperature warmed to only 29 degrees…the all-time record low maximum for the month.
In 1994…the temperature reached a high of 91 degrees at Stapleton International Airport. This was the 60th day of the year that the temperature had reached 90 degrees or more…establishing a new record at that time. The previous record of 52 “90 degree days” occurred in 1978. Only 43 “90 degree days” were recorded at Denver International Airport during 1994.
In 1995…lightning struck a couple in Aurora as they were walking in the rain. The bolt struck the umbrella the man was carrying…injuring both the man and his wife.
In 2000…late afternoon thunderstorms produced strong wind gusts to 76 mph in Westminster…to 69 mph near Boulder…and to 60 mph at Jefferson County airport near Broomfield. No damage was reported.
In 2014…a storm system that moved through the area produced large hail and street flooding in parts of metro Denver and then spread east into the plains. The storm also caused multiple accidents. A semi became detached from a trailer… Blocking traffic on westbound Interstate 70 west of Tower Road. Downed power poles blocked a roadway on CO 79 near Bennett…at mile marker 10. In addition to the damaging winds…the storms produced large hail… From nickel to golfball size across southern and eastern portions of metro Denver. The hailstorm was the most damaging of the 2014 summer season…with insured losses that topped 213 million dollars. Insurance claims included 29297 automobile claims worth more than 87.2 million dollars and 14287 property claims for 126 million dollars…ranking the storm as the eighth most expensive to hit the state. At Denver International Airport…1.01 inches of rainfall was recorded which was the greatest 24-hr rainfall for the date. In addition…a peak wind gust to 38 mph was observed at the airport.
Following on what was a cool but dry August, some are certainly hoping for a bit of precipitation. The month can bring plenty of rain and even our first snow of the season but more often than not, it is one of the most pleasant along the Colorado Front Range.
