Two days in a row Denver has set or tied record low temperatures.
On Friday at 5:55am the temperature at Denver International Airport dropped to 26 degrees easily setting a new low temperature record for October 2nd. The previous record of 30 degrees was set in 1999 and also in 1959. This was the first freeze of the season. Thornton however remained above the freezing mark with a low of 33.1 degrees.
Following on yesterday’s record setting cold, the Mile High City tied a 109 year old low temperature record this morning. The temperature at Denver International Airport dipped to 31 degrees tying the record low for this date last set in 1900. Unlike yesterday, Thornton was actually cooler than the official Denver temperature having recorded a low of 28.2.
The average date of Denver’s first freeze is October 7th so we are a bit ahead on timing. The earliest date Denver has received freezing temperatures is September 8th which occurred in 1962. The latest date was in 1944 when the mercury didn’t dip to freezing until November 15th.
With the first full month of fall here, October usually brings one of the quietest weather months in the Denver area with plenty of mild, sunny days and clear, cool nights. The month actually has our second highest amount of sunshine with 72 percent with September having the most with 74 percent. Interestingly enough, the month following, November, is one of the lowest sunshine months with only 64 percent. Typically October brings our first real taste of winter with the first freeze on average coming on the 7th of the month and the first snow on the 15th of the month.
Average temperatures in October steadily drop throughout the month. On the first we average 72 degree highs but by the 31st that drops to 59 degrees. October also sees our average low temperatures start to reach below freezing as well. At the start of the month we will average 42 degrees as the low temperature but by the end of the month the mercury dips to 30 degrees. This truly begins the sign that winter is approaching.
ThorntonWeather.com has been featured on the City of Thornton’s cable access channel show Thornton 360. The interview which was conducted in June 2009 features the site’s chief amateur meteorologist Tony Hake discussing the features of ThorntonWeather.com, his interest in the weather and more.
Be sure to check out the video below and let us know what you think. You can also watch it on channel 8 throughout the month of September if you have Comcast cable TV.
ThorntonWeather.com would like to thank the City of Thornton’s Communications Department for their work. Oftentimes we forget how many people it takes to make a city of over 100,000 residents run as well as Thornton does and the city’s employees continually perform above and beyond!
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.
This funnel cloud was seen from the Thornton Civic Center (looking north) on June 10th. Image courtesy Lisa Wilson, the City of Thornton.
As summer 2009 comes to a close, it is perhaps most fitting that fall arrives with nearly winter-like weather. We ushered in the summer a month early with a record setting high temperature and soon followed that up with a near constant stream of severe weather for weeks. In fact, most of the events during what was a very active summer season actually occurred in the weeks leading up to the official start of summer.
Even though the official start of summer was a month away, May 19th seemed to be an unofficial start as the mercury climbed to 90 degrees that day setting a new record for the date. The very next day in perhaps what was a sign of things to come, a tornado touched down in Mesa County – only the ninth to strike in that county since 1950.
After a couple weeks of relative calm, the severe weather once again appeared and on June 7th funnel clouds and tornadoes seemed to be appearing everywhere. From the north metro area in Broomfield to Aurora, most of the Front Range had some sort of direct severe weather threat. Most notably,the Southlands Shopping Center was struck by an EF1 tornado where extensive damage to the mall occurred.
September 20 to September 26 - This week in Denver weather history
Looking back at this week in Denver history we start to see more of the signs that summer is coming to an end and fall and winter are right around the corner. Summer-like severe weather can still occur but we also start to see more cold temperatures and occasions with snow become more prevelant.
From the National Weather Service:
20
In 1921…an apparent Bora produced northwest winds sustained to 44 mph with gusts to 64 mph.
In 1955…hail stones 1/2 to 3/4 inch in diameter were reported across parts of the city of Denver.
In 1992…weather observers at Buckley Air National Guard base sighted two tornados southeast of the base. The tornados were short-lived and caused no injuries or damage.
20-21
In 1963…heavy rain and hail caused local flooding in southeast Denver. Thunderstorm rainfall was only 0.60 inch at Stapleton Airport on the 20th.
In 1983…the cold front on the 19th brought an unusually cold air mass into metro Denver for so early in the season. The temperature dipped to a daily record minimum of 28 degrees on both days.
In 1995…a vigorous late summer storm brought the season’s first heavy snow to portions of metro Denver. Millions of trees were damaged and power lines downed as 4 to 8 inches of heavy wet snow settled on fully leafed trees in the Boulder and Denver areas. Branches snapped and trees split under the weight of heavy snow…downing power lines. Firefighters responded to numerous transformer fires. Around 100 thousand people were left without electricity in Boulder and Denver areas alone. It took over a week to fully restore power to some areas. Insurance claims were estimated to be around 6 million dollars to homes in metro Denver and about 500 thousand dollars in damage to automobiles. It was estimated that about 80 percent of 125 million dollars worth of city owned trees in Denver were damaged. Snowfall totaled 7.4 inches at the site of the former Stapleton International Airport where the greatest depth of snow on the ground was only 4 inches due to melting. Temperature records were set on the 21st when the thermometer dipped to a record low reading of 27 degrees and climbed to a high of only 36 degrees… Setting a record low maximum for the date. North winds gusted to 29 mph at Denver International Airport on the 20th.
Hundreds of weather balloons like this are released daily by the National Weather Service. (NOAA)
A 12-year-old boy reportedly received a bit of a shock when he touched a National Weather Service balloon that had landed near Niver Creek Middle School in Thornton. The balloons which are launched twice daily from the old Stapleton International Airport facility and other locations across the nation are essential instruments for forecasters.
The boy complained of numbness in his hands after touching it and school officials called the fire department as they were unsure what the device was. Upon closer inspection they read the labels that said the unit belonged to the National Weather Service and was a weather instrument. The boy was transported to a hospital as a precaution and his father told Channel 7 Wednesday morning that he was fine.
Weather balloons are launched daily from 102 locations across the United States, Caribbean and Pacific and are essential forecasting instruments (see below for a map of sites in the contiguous United States). The six foot diameter balloons are launched twice daily and simultaneously at all the sites at midnight UTC and noon UTC (5:00am MDT and 5:00pm MDT). Once launched, the units can attain an altitude of 115,000 feet and travel up to 200 miles before they burst and fall harmlessly to the ground.
Called a radiosonde, the balloon’s payload measures air pressure, temperature, humidity, wind direction and wind speed. The data is transmitted in real time to receivers on the ground which is then fed into National Weather Service computers and monitored by forecasters. Information obtained by the units is essential for forecasters to evaluate and predict atmospheric conditions for forecasting, severe weather alerting and more.
A funnel cloud near Thornton on Sunday, June 7, 2009. Knowing where to get information on developing weather could save your life. Image courtesy John Wagner, Warrior Legacy Foundation.
We recently updated our weather links page (available from the menu at the left) with dozens more links to a wide array of weather related website. From sites that provide statistical information and historical data to ones where you can become your own weather forecaster, we have it all.
Certainly weather is one of the things that every single person on the globe has in common. It can impact almost every aspect of our daily lives in a myriad of ways. It can make or break that outdoor event, determine whether or not the kids have school today and most notably it can change lives in an instant when it turns severe.
Knowing where to find information about weather can help to educate, inform and possibly save lives – possibly even your own. We have accumulated this extensive list of Internet resources devoted to weather topics on everything from climatology to tropical weather and winter weather.
September 13 to September 19 - This week in Denver weather history
Weather conditions in Colorado can of course vary greatly and we always see that in our weekly look back in the history books. For this week, we see a dizzying array of weather events from record setting temperatures in the 90’s and summer-like thunderstorms with tornadoes to an early arrival of winter that brought a foot of snow!
From the National Weather Service:
13
In 1899…west winds were sustained to 43 mph with gusts to 46 mph.
In 1928…northwest winds were sustained to 41 mph with gusts to 45 mph.
In 1937…an apparent dry microburst produced brief north winds sustained to 31 mph with gusts to 41 mph. There was a trace of rain.
In 1982…torrential rains drenched both the foothills and plains from Denver north. While the heaviest rain occurred north of Denver…just east of Denver 2 1/3 inches of rain fell in 5 hours along with hail that caused minor damage to a few airplanes. Thunderstorm rainfall totaled 0.83 inch at Stapleton International Airport.
In 1993…an upper level system combined with a cold and moist upslope flow to bring the heaviest snowfall to metro Denver for so early in the season. Snowfall from the storm totaled 5.4 inches at Stapleton International Airport; however…most of the snow melted as it fell leaving a maximum of one inch on the ground at any one time. North winds gusted to 21 mph at Stapleton International Airport where a record low temperature of 33 degrees for the date was observed.
In 2002…Friday the 13th proved to be bad luck for several motorists when heavy thunderstorm rainfall caused flooding on I-25 in central Denver. Water rose several feet under the Logan Street overpass…inundating several vehicles. Some motorists were rescued…while others simply waited atop their cars for the flood water to recede. The highway had to be closed in both directions for about 3 hours. The flooding was exacerbated by poor drainage due to the construction along the highway. A 12-foot drainage pipe had not yet been installed beneath the underpass. The deluge also flooded several businesses along Broadway.
September 6 to September 12 - This week in Denver weather history.
Colorado weather is certainly varied and this week’s look back at weather history proves that. We have seen everything from deadly lightning, hail and severe winds to even snow during the second week of September.
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.
5-9
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.
Two days in a row Denver has set or tied record low temperatures. 
ThorntonWeather.com has been featured on the City of Thornton’s cable access channel show Thornton 360. The interview which was conducted in June 2009 features the site’s chief amateur meteorologist Tony Hake discussing the features of ThorntonWeather.com, his interest in the weather and more.
