November 2023 preview: The transition to winter begins

Thornton's November weather previewThe weather during the month of November in Denver metro area can offer just about anything.  While it is normally a quiet month, it can be prone to extremes.

November has historically been one of Denver’s snowiest months and major snowstorms are not entirely uncommon.  However conditions can also be quite dry.

Temperatures during the month continue to cool as we get closer to winter and by the end of the month the low temperatures routinely dip to 20 degrees or below.  At times it can in fact bring conditions more like what we see in January.

Get all the details on November’s weather and what we can expect in our complete preview here.

Time to “fall back” as Daylight Saving Time ends Sunday, November 5

Daylight Saving Time
The United States returns to Standard Time at 2:00am Sunday as Daylight Saving Time comes to an end.

The biannual ritual of changing our clocks to adjust for Daylight Saving Time occurs this weekend, providing yet another signal of the changing of seasons.  The United States will ‘fall back’ one hour at 2:00am Sunday morning as we return to Standard Time.

The ritual of changing our clocks twice a year can be met with some resistance as some people struggle to adjust their body’s internal clock.  Others actually like the return to standard time as they get to enjoy an extra hour of sleep.

The time change definitely has big effects on the dawning of daylight and how early it gets dark in the evening.

Sunrise on Saturday occurs at 7:31am but on Sunday it will be at 6:32am. Similarly, sunset will occur at 5:54pm on Saturday but on Sunday the sun will disappear over the horizon at 4:53pm.

For many this means that when they get home from work it will now be dark and outdoor activities will be significantly curtailed as a result.

Arizona and Hawaii are the only states that do not observe Daylight Saving Time and remain on Standard Time year round.    The U.S. territories of Puerto Rico, American Samoa, Guam, Northern Mariana Islands, and the United States Virgin Islands also do not observe the event.

It won’t be all that long though before Daylight Saving Time returns.  On March 10, 2024 we will ‘spring forward.’

Daylight Saving Time Schedule

The mandated beginning and end of Daylight Saving Time has changed in the United States over the years.

The most recent schedule was set by the Energy Policy Act of 2005 and took effect in 2007.  We now ‘spring forward’ to begin Daylight Saving Time on the second Sunday in March and ‘fall back’ with the return to Standard Time on the first Sunday in November.

Daylight Savings Time Dates

Year DST Begins 2 a.m.
(Second Sunday in March)
DST Ends 2 a.m.
(First Sunday in November)
2023 12 March 2023 5 November 2023
2024 10 March 2024 3 November 2024
2025 9 March 2025 2 November 2025
2026 8 March 2026 1 November 2026
2027 14 March 2027 7 November 2027
2028 12 March 2028 5 November 2028
2029 11 March 2029 4 November 2029

October 2023 top shots: Monthly photo slideshow

The annular solar eclipse as seen from southern Utah. (Diana Mauzy)
The annular solar eclipse as seen from southern Utah. (Diana Mauzy)

October in Thornton can bring a wide variety of weather conditions, perfect for the photographer in all of us.

The month brings the changing of the colors at Colorado’s lower elevations and it is also is typically when we see our first freeze and first snow.

Couple those facts with our usual widely varying landscapes and wildlife and we have a month that is sure to bring in plenty of photo opportunities.

  • Slideshow updated October 31, 2023
  • 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=”72177720311994744″]

What is missing in the slideshow above?  Your photo!

Our monthly photo slideshow is going to feature images that we have taken but more importantly images that you have captured.  The photos can be of anything even remotely weather-related.

Landscapes, current conditions, wildlife, pets, kids.  Whimsical, newsy, artsy.  Taken at the zoo, some other area attraction, a local park, a national park or your backyard.  You name it, we want to see and share it!

Images can be taken in Thornton, Denver or anywhere across the extraordinary Centennial State.  We’ll even take some from out of state if we can tie it to Colorado somehow.

We’ll keep the criteria very open to interpretation with just about any image eligible to be shown in our slideshows.

What do you win for having your image in our slideshow?  We are just a ‘mom and pop’ outfit and make no money from our site so we really don’t have the means to provide prizes.  However you will have our undying gratitude and the satisfaction that your images are shared on the most popular website in Thornton.

To share you images with us and get them included in the slideshow just email them to us or share them with ThorntonWeather.com on any of the various social media outlets.  Links are provided below.

So come on, get those camera’s rolling!

October 29 to November 4: This week in Denver weather history

This Week in Denver Weather History

The further we go into the cold season, the more we see significant winter-like events in our look back at Denver weather history. Many significant snowstorms have occurred this week in the past including one in 1946 that dumped more than 30 inches of snow on Denver.

From the National Weather Service:

27-30

In 2009…a powerful early season storm brought heavy snow to the Front Range. The combination of a deep northeasterly upslope flow coupled with abundant moisture and lift with the developing storm system produced an extended period of moderate to heavy snowfall. The heavy wet snow accumulated on trees and resulted in broken branches and scattered electrical outages. Interstates 70 and 76 were closed east of Denver. Numerous other roads and highways were shut down. The Red Cross set up numerous emergency shelters for stranded travelers. The blowing snow at Denver International Airport forced the cancellation of hundreds of flights. Schools were also closed. In the foothills storm totals included: 46 inches… 3 miles southeast of Pinecliffe; 42 inches…3 miles southwest of Conifer; 34 inches…3 miles north of Blackhawk; 30 inches at Aspen Springs and near Evergreen… 23 inches at Roxborough Park…and 20 inches…3 miles south-southeast of Morrison. Across the Urban Corridor storm totals included: 25 inches in Highlands Ranch; 21.5 inches near Louisville…20.5 inches in Broomfield…20 inches at Lafayette…17.5 inches in Boulder…17 inches in Westminster…16.5 inches in Erie; 15.5 inches in Arvada and 5 miles west-northwest of Littleton…15 inches in Littleton…14 inches in Englewood…13.5 inches in Lakewood and 6 miles north of Thornton; 13.3 inches at Denver International Airport…11 inches…4 miles south of Denver; 10.5 inches…2 miles north of Cherry Hills Village and Niwot.

28-29

In 1993…an upper level disturbance combined with a moist upslope flow to bring heavy snow to portions of metro Denver. Snowfall amounts ranged from 5.4 inches at Stapleton International Airport to 14 inches in Boulder. New snowfall totaled 8 inches at Gross Reservoir in the foothills 5 miles southwest of Boulder. On the 28th…north winds gusted to 30 mph at Stapleton International Airport where the temperature climbed to only 25 degrees on the 29th…equaling the record low maximum for the date.

28-30

In 1971…a vigorous cold front plunged temperatures from a high of 70 degrees on the 27th to record low levels on the 29th and 30th. Snowfall totaled 3.1 inches at Stapleton International Airport where north winds gusted to 23 mph. Some freezing drizzle also fell on the 28th. Record daily low maximum temperatures of 32 degrees on the 28th and 25 degrees on the 29th were established along with a daily record minimum of 13 degrees on the 30th.

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

In 1917…the all-time lowest recorded temperature in October…2 degrees below zero…occurred. This is also the earliest below zero reading of the season.

In 1939…the first measurable snow of the season totaled 5.6 inches in downtown Denver. Post-frontal northeast winds were sustained to 28 mph.

In 1961…heavy snowfall measured 6.0 inches at Stapleton Airport where northeast winds gusted to 30 mph.

In 1973…strong winds caused some damage to homes…stores… And utility lines along the foothills from metro Denver south.

In 1981…high winds buffeted the Front Range foothills with gusts to 55 mph in south Boulder.

In 1996…high winds gusting from 70 to around 100 mph blasted metro Denver. One man was killed when a strong wind gust overturned a pop-up camper onto him while he was trying to secure it. In addition…five people at the Rocky Flats Environmental Test Facility received minor injuries when several windshields were blown out of their cars…spraying glass onto the occupants. Several trees and power lines were also downed. Two 75-foot high pine trees were uprooted at the Mt. Olivet cemetery in Arvada. Property damage from the windstorm ran into the millions of dollars. The highest recorded wind gusts included: 101 mph at Jefferson County Airport near Broomfield…100 mph in Golden Gate Canyon…96 mph in Coal Creek Canyon…and 87 mph at upper Table Mesa in Boulder. West-northwest winds gusted to 43 mph at Denver International Airport. Insured damage from the wind storm totaled 5.2 million dollars…the third most costly storm of record in Colorado at the time.

In 2003…strong Chinook winds developed in and near the Front Range foothills. Winds gusting to 80 mph in Boulder downed several trees and power lines…causing damage and triggering scattered electrical outages. The combination of strong winds…very dry fuel conditions…and downed power lines sparked two large wildfires. The overland wildfire in Boulder County…near Jamestown…consumed nearly 3900 acres and destroyed 12 structures…including homes…trailers…and out-buildings. Preliminary damage estimates for the value of lost property was nearly one million dollars. In Douglas County…the Cherokee Ranch wildfire consumed 1200 acres and destroyed 4 structures. The large smoke plumes from both fires were highly visible across metro Denver. West winds gusted to 45 mph at Denver International Airport.

29-30

In 1905…heavy snowfall developed on the evening of the 29th and continued through the evening of the 30th. Snowfall totaled 11.0 inches in downtown Denver. Precipitation was 1.02 inches. Temperatures were generally in the 20’s.

In 1959…rain during most of the day on the 28th changed to snow early on the 29th and continued through most of the 30th. Heavy snowfall totaled 7.4 inches at Stapleton Airport. North-northeast winds gusted to 24 mph on the 30th. Some freezing drizzle also occurred on the 30th.

In 1981…4 to 8 inches of new snow were recorded in the foothills west of Denver. Snowfall totaled only 0.4 inch at Stapleton International Airport where north winds gusted to 25 mph.

In 2019…a strong storm system brought record breaking temperatures and up to a foot of new snow to parts of Denver…especially across the south and southeast portions of the metro area down to the Palmer Divide. In Denver… a record low maximum temperatures of 18 was set on the 29th… followed by a record low temperatures of 3 degrees on the 30th. The combination of snow and wind along the Interstate 70 corridor east of Denver forced its closure in both directions for several hours due to drifting snow and poor visibility. One weather related traffic fatality…occurred in the foothills west of Denver which closed State Highway 6. The official snowfall measurement at Denver International Airport was 7.7 inches. Numerous schools in and around the Denver area and to the east were closed due to heavy snow and hazardous road conditions. Cancellations and delayed flights at Denver International Airport left 800 passengers stranded at the airport overnight. Along the urban corridor and Palmer Divide storm totals included: Storm totals included: 12 inches at Ponderosa Park…10 inches near Foxfield; and Parker; 8.5 inches in southwest Aurora; near Buckley AFB…Cherry Creek…east Denver…and southwest Aurora; 8 inches in Boulder and near Elizabeth…Federal Heights…Louisville and Westminster; 7.5 inches near Castle Pines…7 inches in southwest Aurora and near Shamballa and Quincy Reservoir; 6.5 inches near Rocky Flats; 6 inches near Byers…Elbert…Greenwood and Lakewood. Continue reading October 29 to November 4: This week in Denver weather history

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

This Week in Denver Weather History

It’s not quite Halloween but leading up to the holiday we see plenty of ‘scary’ weather in our look back at this week in Denver weather history. High winds are relatively commonplace and so too are major snowstorms. One recent event in 1997 dumped 14 to 31 inches of the white stuff on the metro area.

From the National Weather Service:

18-23

In 2003…an extended warm spell resulted in 5 new temperature records. The high temperature of 84 degrees on the 18th equaled the record high for the date. High temperatures of 86 degrees on the 19th…83 degrees on the 21st…and 84 degrees on the 22nd were record highs for the dates. Low temperature of 49 degrees on the 23rd was a record high minimum for the date. Low temperatures during the period were in the 40’s and lower 50’s.

19-23

In 1906…heavy snowfall totaled 22.7 inches in the city over the 5 days. Rain changed to snow on the evening of the 19th…and snow continued through the late afternoon of the 23rd. The heaviest amount of snowfall…16.0 inches…fell from 8:00 pm on the 20th to 8:00 pm on the 22nd. The most snow on the ground was 13.3 inches on the evening of the 23rd. This was the first snow of the season and the only snow of the month. Winds during the storm were from the north at sustained speeds of 20 to 30 mph each day. Temperatures during the storm were generally in the 20’s.

22

In 1878…winds were sustained to 42 mph.

In 1887…the first measurable snow of the season occurred… Ending the longest snow-free period in Denver…232 days… Since the last snow on March 5th.

In 1947…the first snow of the season totaled only 1.6 inches. Post-frontal north winds caused temperatures to plunge from a high of 60 degrees at midnight to a low of only 30 degrees 24 hours later. This was the only snow of the month.

In 1985…high winds gusting from 60 to 80 mph buffeted the Front Range foothills. The strongest reported wind gust was 89 mph in eastern Boulder. A treehouse east of Boulder was set on fire by a downed power line. Two people in Boulder were injured. A woman broke her arm when the strong winds knocked her to the ground. A carpenter in the city suffered a severely cut hand while he was trying to repair a roof that was being torn from a building. At Stapleton International Airport…northwest winds gusted to 41 mph.

In 2001…west-northwest winds gusting as high as 54 mph warmed the temperature to a high of 70 degrees at Denver International Airport.

22-23

In 1914…post-frontal rain changed to snow. Precipitation totaled 2.72 inches…most of which was in the form of moist snow which melted as it fell in the business section of the city. About 3 inches of snow was measured on lawns in the residential areas on the morning of the 24th. Official snowfall totaled only 0.4 inch downtown… But an estimated 8.0 inches of snow melted as it fell. North to northeast winds were sustained to 29 mph with gusts to 30 mph on both days.

In 1975…a vigorous cold front moving across metro Denver followed by strong northeast winds gusting to 52 mph produced billows of blowing dust and plunged the temperature 21 degrees in an hour. The surface visibility was reduced to 1/4 mile in blowing dust at Stapleton International Airport. The temperature cooled from a daily record high of 81 degrees to a low of 38 degrees by day’s end. The first snowfall of the season totaled 2.7 inches on the 23rd. This was the only measurable snow of the month at Stapleton International Airport.

In 1995…heavy snow fell on the Palmer Ridge south of Denver and in the foothills west of Denver where snow amounts ranged from 4 to 8 inches. Sedalia…south of Denver… Received 8 inches of snow. Winds strengthened on the plains and produced blizzard conditions…reducing surface visibilities to less than 1/4 mile. I-70 was closed from just east of Denver at Gun Club Road to the Kansas border. Ten inches of snow fell at Strasburg east of Denver where north winds at sustained speeds of 35 to 45 mph with gusts as high as 60 mph produced 2 to 4 foot drifts. Snowfall totaled only 2.2 inches at the site of the former Stapleton International Airport. North winds gusted to 51 mph at Denver International Airport.

23

In 1876…skies were fair…but winds were sustained to 48 mph.

In 1942…a major storm dumped 10.2 inches of snow over downtown Denver. Post-frontal northeast winds were sustained to only 13 mph.

In 1955…the first snowfall of the season and the only measurable snow of the month dumped 4.1 inches of snow on Stapleton Airport. This was the single heaviest October snowfall in 13 years since 1942. The storm also brought the first sub-freezing temperatures of the season when the temperature dipped to a low of 25 degrees.

In 1956…southwest winds gusted to 53 mph and produced some blowing dust at Stapleton Airport.

In 1967…a northwest wind gust to 51 mph was recorded at Stapleton International Airport. In downtown Boulder… Winds were sustained at 20 mph with gusts in excess of 40 mph.

In 1981…strong winds occurred in the foothills. Wind gusts to 70 mph were reported at Wondervu.

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.

23-25

In 2021…after several weeks of warm…windy and dry weather that fueled the two largest wildfires in the state`s history; a powerful storm system brought welcome relief as it produced heavy snow and frigid temperatures Denver and the Front Range. In the Front Range mountains and foothills… storm totals ranged from 10 to 20 inches. Along the urban corridor…storm totals from 4 to 12 inches were observed… with the heaviest amounts along and generally west of I-25 and over Weld County…where localized bands of heavy snow Some storm totals included 14.3 inches near Allenspark; and 12.9 inches in southeast Boulder and Nederland…with 12.8 inches near Loveland. At Denver International Airport…4.0 inches of snowfall was observed. Continue reading October 22 to October 28: This week in Denver weather history

Denver sets new record high temperature for October 20

Record High Temperature

We knew it was going to be unusually warm today and Mother Nature did not disappoint. In fact, the Mile High City broke a 73 year old record.

As measured at Denver International Airport, Denver’s high temperature today topped out at 86 degrees. This easily bested the previous record high for October 20th of 83 degrees set in 1950.

Here in Thornton, we lagged Denver much of the day but in the end, managed an extra degree above them, topping out at 87 degrees.

We will cool down about 10 degrees for the balance of the weekend. Conditions will remain dry and calm.

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

This Week in Denver Weather History

Snow and wind are two common conditions we see this time of year and our look back at this week in Denver weather history certainly has those type of events. Also notable is a surprising October hail storm in 1998 that went into the books as one of the costliest in history.

From the National Weather Service:

13-16

In 1873…smoke from several large forest fires in the mountains made the air very hazy in the city.

15

In 1871…a terrible wind occurred during a snow storm in the foothills above Boulder. Damage was minor.

In 1878…high winds reached sustained speeds of 60 mph at times.

In 1911…post-frontal northwest winds were sustained to 41 mph with gusts to 43 mph.

In 1948…strong winds struck the Boulder area. Winds averaged 50 mph at Valmont just east of Boulder. Wind gusts in excess of 60 mph were recorded at the Boulder airport. Wind gusts to 40 mph briefly reduced the visibility to 1 1/2 miles in blowing dust at Stapleton Airport.

In 1980…a rare October tornado touched down in Boulder… Damaging a vocational training building and throwing three nearby cars together damaging them extensively. A mile and half away several camper vehicles were thrown 200 feet. The storm also produced 1 inch diameter hail in the Boulder area.

15-16

In 1928…a thunderstorm produced hail shortly after midnight on the 15th. Rain changed to snow by evening. Through the afternoon of the 16th…the heavy snowfall totaled 7.3 inches in the city. North winds were sustained to 23 mph on the 15th.

In 1984…the heaviest October snowstorm in several years hit eastern Colorado with a vengeance. The storm was known as the “Bronco Blizzard” since it occurred during a nationally televised Monday Night Football game in Denver. One to two feet of snow fell near the foothills in west metro Denver with 2 to 3 feet in the foothills. Wind gusts up to 55 mph whipped the snow into drifts as high as 4 feet. The storm closed schools…roads…and airports. I-70 was closed both east and west of Denver. I-25 was closed south to Colorado Springs. Flights were delayed for several hours at Stapleton International Airport. Power outages were widespread. Snowfall totaled 9.2 inches at Stapleton International Airport where north winds gusting as high as 40 mph caused frequent surface visibilities of 1/4 to 1/2 mile in moderate to heavy snow and blowing snow overnight. The high temperature of only 35 degrees on the 15th was a record low maximum for the date.

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

In 1878…high winds reached sustained speeds of 60 mph.

In 1998…one of the costliest hail storms to ever hit metro Denver caused an estimated total of 87.8 million dollars in damage to homes…commercial buildings…and motor vehicles. At the time the storm was ranked as the 7th costliest ever. The hailstorm…rare for so late in the season…began over portions of Arvada…Wheat Ridge…and northwest Denver where mostly pea sized hail accumulated up to a depth of 6 inches near I-70. Several accidents were attributed… At least in part…to the hailstorm. Snowplows had to be called out to clear several city streets. The storm intensified as it moved to the east…into the Denver and Aurora areas. Large hail…up to 2.00 inches in diameter pounded east and southeast metro Denver. Two inch diameter hail fell in the city of Denver and at Buckley Field. Hail as large as 1 1/2 inches was measured in south Denver with 1 inch diameter hail in northern Aurora.

In 1999…upslope conditions produced snow across metro Denver with heavy amounts in the nearby foothills. Snowfall totals included: 9 inches at Eldorado Springs; 8 inches at Genesee… Golden Gate Canyon…Littleton and near Morrison; 7 inches near Nederland; and 6 inches in Louisville. Snowfall totaled 3.6 inches at the site of the former Stapleton International Airport.

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.

In 2012…A brief but powerful windstorm associated with a fast moving cold front across the Urban Corridor and adjacent plains during in the evening. Peak wind gusts ranging from 58 to 71 mph downed trees and power lines which damaged homes and vehicles. Several temporary structures were also damaged. Approximately fifty thousand were left without power in the Denver…Fort Collins and Greeley areas. Some schools were closed the following day until power could be restored. Around the Denver area…peak wind gusts included: 69 mph in Golden…64 mph at Littleton…62 mph at Buckley AFB and in Denver…near the intersection of Walnut St. and Interstate 25…and Longmont; 59 mph at Centennial Airport…58 mph at Denver City Park… Highlands Ranch.  At Denver International Airport…a peak wind gust to 35 mph was observed from the northwest.

17-19

In 1908…a moist…heavy…wet snowfall totaled 13.0 inches in downtown Denver over the 3 days. Rain from early morning on the 17th changed to snow by late afternoon and continued through the late morning of the 19th. Due to temperatures in the 30’s and melting…the most snow on the ground was only 5.0 inches at 6:00 pm on the 18th. Northwest to northeast winds were sustained between 12 and 20 mph during the storm. Precipitation totaled 1.82 inches.

18

In 1875…the haze was so dense that the mountains were not visible from downtown Denver for most of the day.

In 1937…a vigorous cold front produced north winds sustained to 32 mph with gusts to 41 mph. Rain and snow totaled 0.16 inch. Post-frontal snowfall of 0.8 inch was the only snowfall of the month.

In 1960…post-frontal upslope rain changed to snow. Snowfall was 2.2 inches at Stapleton Airport where precipitation (rain and melted snow) totaled 1.58 inches.

In 1971…wind gusts to 48 mph were recorded in downtown Boulder. West winds gusted to 30 mph at Stapleton International Airport.

In 1999…heavy snow developed in the foothills west of metro Denver with lesser amounts across the city. Snowfall totals included: 7 inches near Nederland…6 inches in Boulder…and 5 inches at Chief Hosa. Only 1.2 inches of snow were measured at the site of the former Stapleton International Airport.

18-23

In 2003…an extended warm spell resulted in 5 new temperature records. The high temperature of 84 degrees on the 18th equaled the record high for the date. High temperatures of 86 degrees on the 19th…83 degrees on the 21st…and 84 degrees on the 22nd were record highs for the dates. Low temperature of 49 degrees on the 23rd was a record high minimum for the date. Low temperatures during the period were in the 40’s and lower 50’s.

19

In 1887…northwest winds sustained to 42 mph were recorded in the city.

In 1982…3 to 6 inches of snow fell over northwest metro Denver…including Boulder. Only 1.2 inches of snowfall were recorded at Stapleton International Airport where north winds gusted to 35 mph. This was the first measurable snowfall of the season.

19-20

In 1990…an early winter storm dumped heavy snow across metro Denver. Snowfall amounts ranged from 4 to 8 inches in the foothills above 6500 feet elevation…4 to 7 inches in the Castle Rock area…and 2 to 5 inches across most of metro Denver and Boulder. Snowfall totaled 3.6 inches at Stapleton International Airport where northwest winds gusting to 48 mph kicked up some blowing dust shortly after a cold frontal passage on the 19th. However… Temperatures were warm enough to keep most roadways wet and slushy at lower elevations.

19-23

In 1906…heavy snowfall totaled 22.7 inches in the city over the 5 days. Rain changed to snow on the evening of the 19th…and snow continued through the late afternoon of the 23rd. The heaviest amount of snowfall…16.0 inches…fell from 8:00 pm on the 20th to 8:00 pm on the 22nd. The most snow on the ground was 13.3 inches on the evening of the 23rd. This was the first snow of the season and the only snow of the month. Winds during the storm were from the north at sustained speeds of 20 to 30 mph each day. Temperatures during the storm were generally in the 20’s.

20

In 1878…between 3:00 pm and 4:00 pm wind speeds averaged 48 mph with a maximum 1 minute sustained velocity to 96 mph at both 3:27 pm and 3:48 pm in downtown Denver. This is the highest sustained wind speed ever recorded in the city.

In 1986…a rare late October thunderstorm produced 3/4 inch diameter hail at centennial airport. Hail piled up 2 1/2 inches deep…causing some street flooding in south metro Denver.

In 2019…strong bora winds swept across the foothills and adjacent plains. Peak gusts included: 82 mph…3 miles southwest of Rocky Flats; 78 mph near White Ranch Open Space; 75 mph near Genesee and Georgetown; with 63 mph at Firestone. At Denver International Airport…a peak gust of 49 mph was observed from the west.

20-21

In 2007…a storm system brought heavy snow to the southern Denver suburbs as well as the palmer divide south of Denver. Storm totals included: 7.5 inches near Castle Rock…lone tree and greenwood village…with 6.5 inches at Elizabeth. Snow drifts up to 2 feet deep were observed 6 miles south-southwest of Elizabeth. In the Denver Stapleton area…2.0 inches of snow was observed.

20-22

In 1936…5.5 inches of snow fell over downtown Denver. Most of the snow…4.5 inches…fell on the 20th.

21

In 1920…the rare event of snow from a thunderstorm occurred in the city during the evening. Brilliant flashes of lightning and loud peals of thunder were first noted at 7:35 pm. Light rain began falling at 8:30 pm…and light moist snow began falling a few minutes later. Some soft hail was also seen falling with the rain and snow…but both melted almost as fast as they fell. The hail only continued for a few minutes…and the rain and snow ceased about 9:40 pm. The snowfall was the first to occur in Denver this season. The amount of precipitation at the station measured only 0.01 inch…but heavier amounts were reported from other parts of the city. Snowfall was only a trace.

21-22

In 1978…heavy rain on the 21st changed to snow by daybreak on the 22nd and continued the rest of the day. This was the first measurable snowfall of the season…but totaled only 1.7 inches at Stapleton International Airport where east winds gusted to 29 mph. While only a trace of snow covered the ground…precipitation totaled 1.27 inches.

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

This Week in Denver Weather History

Denver has yet to get a taste of wintry weather this year as we continue what has been a very dry period the last few months. In the past that hasn’t always been the case and our look back at this week in Denver weather history shows that heavy, winter-like snowstorms can and do strike in October.

From the National Weather Service:

7-8

In 1990…the season’s first snow occurred. Snowfall amounts varied from 3 to 7 inches across metro Denver. Snowfall totaled 4.0 inches at Stapleton International Airport where north winds gusted to 29 mph.

8

In 1923…southeast winds were sustained to 44 mph with gusts to 47 mph. The strong winds persisted through the afternoon. The high temperature of 77 degrees was the warmest of the month that year.

In 1975…a wind gust to near 100 mph was recorded in Boulder. Frequent wind gusts to 60 mph were reported along the foothills causing only minor damage. West winds gusted to 45 mph at Stapleton International Airport.

8-9

In 2017…an early season snowstorm produced heavy wet snow which broke branches and downed power lines. About ninety-eight thousand outages occurred in Denver and the surrounding metro area. Almost half the outages were very short…while 54210 were sustained outages that lasted longer than five minutes. Some however lasted for several hours. Snow amounts varied greatly along the Interstate 25 Corridor. West of I-25…storm totals included: 7.5 inches in Arvada…7 inches in Broomfield…6 inches Boulder and Louisville…with 5 inches at Ralston Reservoir. East of I-25…storm totals ranged from a trace to 4 inches. In the mountains and foothills…storm totals included: 12.5 inches near Genesee…10 inches at Eldorado Springs… Idledale and Nederland…with 8.5 inches near Jamestown.

9

In 1910…light smoke from forest fires in the mountains was sighted over the city.

In 1982…northwest winds gusted to 49 mph at Stapleton International Airport.

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.

In 2019…a vigorous winter like storm system brought intense northerly winds and the cold front blasted through the urban corridor. Peak wind gusts from 50 to 60 mph accompanied the front. Some trees in Denver were uprooted by the strong winds. Light rain and drizzle overnight…changed over to the season`s first snow during the predawn hours of the 10th. Bands of moderate to heavy snow brought 2 to 6 inches of snow in the Front Range mountains…foothills and urban corridor. The morning commute was especially hazardous as falling temperatures froze wet roads. Multiple crashes occurred including: I-25 in Denver…I-70 from Denver west to the Eisenhower Tunnel and State Highway 285 towards Fairplay. Over 300 crashes were reported in Denver and Aurora alone. After reaching a maximum temperatures of 83 degrees on the afternoon of the 9th…the temperature plummeted to 13 degrees on the 10th. A temperature change of 70 degrees…the second largest 2-day swing for the month of October in Denver weather history. Continue reading October 8 to October 14: This week in Denver weather history

Thornton’s October 2023 preview: Generally calm conditions with our first freeze and snow

Thornton, Colorado October weather preview.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.

October is historically the second sunniest month and conditions are generally calm.

However we also will usually see our first taste of winter during the month with the first freeze and first snowfall of the season.  Temperatures as well will start to drop and by the end of the month the average nighttime lows are below freezing.

For complete details on our historical October weather and what we can expect in the coming month, read our complete October weather preview here.

  • Don’t miss a thing when it comes to our ever-changing weather! Be sure to ‘like’ us on Facebook and follow us on Twitter.

September 2023 weather recap: Another warm, wet month

September 2023 Temperature Summary for Thornton, Colorado.
September 2023 Temperature Summary for Thornton, Colorado.

For the third month in a row, September brought above average temperatures and above average precipitation to Thornton. The month was, however, lacking of much drama making for a pretty quiet month.

Thornton’s average temperature for the month came in at 66.2 degrees. That was a good bit above our running 17-year average of 64.0 degrees. Temperatures ranged from a high of 100 degrees on the first down to 43 degrees on the 16th and 25th.

Denver, as measured at Denver International Airport, saw even warmer temperatures. The Mile High City’s average temperature was 68.0 degrees, 3.2 degrees above their September average. It tied Denver’s record for the 8th warmest September on record (since 1872).

In terms of precipitation, Thornton’s September came in at a healthy 2.47 inches. That was nearly an inch above our 17-year running average for the month of 1.49 inches. Much of that, however, came in a single afternoon deluge on the 14th that dumped 1.90 inches of rain.

Denver saw considerably less precipitation (as measured at DIA) with a mere 0.67 inches falling in their bucket. That was well below the Mile High City’s September average of 1.35 inches.

No snowfall was recorded in Thornton or Denver for the month.

Click here to view Thornton’s complete September 2023 climate summary report.

September 2023 Precipitation Summary for Thornton, Colorado.
September 2023 Precipitation Summary for Thornton, Colorado.

Weather, natural disasters & climate news and information.