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.
Thornton, Colorado temperature summary for August 2025. (ThorntonWeather.com)
A recurring theme from most of 2025 for August. Thornton once again saw temperatures above normal and precipitation below, something that has happened far too often this year.
Above normal temperatures dominated the first three weeks of the month. Mercury readings in the 90s were common with only three days being below that mark. Precipitation was absolutely scarce with a mere 0.01 inches being recorded during the first 21 days of the month.
Thankfully, Mother Nature took mercy on us for the last 10 days of August. We saw temperatures cool a good bit with every day seeing below average readings. While precipitation wasn’t great, she also was kind enough to finally give us a couple days with much-needed rain.
Temperatures in Thornton came in at an average of 72.6 degrees for the month. This was a good bit above the 19-year running average for August of 71.8 degrees. It was also the sixth month in a row for Thornton with above average temperatures.
Out at DIA where Denver’s official records are taken, it was a good bit warmer. The Mile High City saw an average of 73.8 degrees for August 2025. This was above their long term average for August of 72.9 degrees.
In terms of precipitation, Thornton ended up with 0.51 inches in the bucket. Virtually all of that fell in the last seven days of the month. It was well below our running August average of 1.20 inches.
For Denver, they saw two days with thunderstorms that dumped a great deal of rain on the airport, storms that missed us. As a result, their rain total for the month was a surprising 4.12 inches. This was well above their long term average for August of 1.58 inches.
Following an August that was unseasonably warm, we find ourselves heading into September hoping for relief. 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 2013’s devastating floods brought on by record-setting rain. Longtime residents might remember September 1971 which brought over 17 inches of snowfall.
The Farmers’ Almanac released its 2025 – 2026 winter outlook and if it were to bear out, Colorado could be in for some harsh, wintry weather.
The publication portends a “very cold, snowy” winter for the north central plains. It says the region is, “set for a classic winter wonderland.”
Founded in 1818, the Farmers’ Almanac’s forecasts use a “tried-and-true formula that adapts to the mysteries of nature and the ever-changing world in which we live. The basis of our prediction method was developed by our founding editor according to correlations between celestial events, and various meteorological conditions.”
Of course, long range forecasts this far out, no matter who is making them, have to be taken with a grain of salt. However, as Thornton has seen four straight snow seasons with below normal levels of the white stuff, a change might be welcome.
As summer vacations wind down and families prepare to send their kids back to school in August, Colorado weather also starts to settle down. The chances for severe weather decrease markedly during August and by the end of the month daytime temperatures are dropping quite a bit as well.
Thornton, Colorado’s July 2025 Temperature Summary. (ThorntonWeather.com)
If you were thinking the past month was hot and dry, you would certainly be correct. Thornton’s July saw average mercury readings a good bit above average and precipitation well below average.
Looking back, probably one of the most notable things about the month was that there wasn’t a whole lot notable. We saw nothing significant in the way of severe weather and while it was hot, it wasn’t overly extreme. It was noteworthy that the last two weeks of the month were quite dry yielding only 0.03” of rain over the period.
Thornton’s average temperature for the month came in at 75.2 degrees. This was a good bit above our running 18 year average for July of 73.9 degrees. Temperatures ranged from a high of 102.1 degrees on the 9th down to 55.3 degrees on the 11th.
Out at DIA where the Mile High City’s official measurements are taken, similar readings were seen. Denver saw an average temperature for the month of 75.1 degrees. This actually matched their long-term average for July.
In terms of precipitation, Thornton saw 0.63 inches fall in its rain bucket. The majority of that fell during the first half of the month. That is well below our running average for July of 1.88 inches.
For Denver, they recorded similar precipitation with 0.64 inches being recorded. This was well below their July average of 2.14 inches.
Thornton, Colorado’s June 2025 Temperature Summary. (ThorntonWeather.com)
Finally, a break from the heat and some much-needed precipitation. Thornton’s average temperature for the month came in a bit above average but not by much. In terms of precipitation, we saw a good bit above average levels.
Change is of course the one constant in Denver’s weather but come July, things actually get pretty consistent.
The standard formula for a day in July is a sunny morning, clouds developing in the late morning and early afternoon. Come mid-afternoon, thunderstorms are rolling off of the foothills and into the metro area and the eastern plains. These storms do occasionally reach severe status containing hail, gusty winds and heavy downpours of rain.
Thornton, Colorado snow summary for the 2024 / 2025 season. Click for larger view. (ThorntonWeather.com)
The snow season in Colorado runs July 1 to June 30 and thus today ends the 2024 / 2025 season officially. With the close, we can see Thornton did not fare too well this winter.
We ended up with 36.9 inches for the season. That is far below our 18-season running average of 54.6 inches per season. It also puts the 2024 / 2025 season into the books as the fourth least snowy over that period.
Out at DIA where Denver’s official measurements are taken, they fared better with 47.7 inches. The difference is largely due to a period from November 5 to November 8 in which the bulk of the snow for that event stayed just east of Denver. Over those four days, DIA recorded 18.2 inches versus 10.8 inches here in Thornton.
Extreme weather can occur during in month in Colorado we well know. June however is when traditional spring severe weather arrives in the state oftentimes with hail, damaging wind and tornadoes.
Over 40 percent of the tornadoes that occur in Colorado happen during the month of June. Far more common are thunderstorms with hail and wind, each responsible for extensive damage each year.
While severe weather is common, so too are brilliantly sunny and mild days as we close out spring and enter summer. If you are looking for cold, it isn’t likely but it is possible as the Denver area has seen freezing temperatures and yes, even snow, during the month.
