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.
Thornton, Colorado’s May 2025 Temperature Summary. (ThorntonWeather.com)
Thornton recorded its third month in a row with average temperatures above normal. The month did, however, at least offer up near average levels of precipitation.
Thornton, Colorado’s April 2025 Temperature Summary. (ThorntonWeather.com)
April typically brings cool temperatures and a nice shot of precipitation to Thornton. That was not the case this year as we recorded our 3rd warmest and 3rd driest April on record.
We started out on the cool side of things for the first five days of the month and saw a little bit of snow and rain.
The next thirteen days, however, saw a turn toward temperatures well above normal including some 80+ degree days. Precipitation was similarly scarce with only one day recording a minimal snowfall.
We did then see a quick return to wintry weather on the 18th and 19th with below normal temperatures and our biggest snowfall of the month, a mere 2.5 inches.
Above normal temperatures then returned for all but one day of the rest of the month. We did see two minor precipitation events during the final week.
Thornton’s average temperature for April 2025 came in at 50.1 degrees. This was a good bit above our 19-year running average for the month of 48.5 degrees. It put the month in the book as our third warmest April during that period. Highs ranged from a maximum of 87.7 degrees on the 12th down to a low of 25.3 degrees on the 3rd.
As measured at Denver International Airport, Denver saw an average temperature for the month of 48.5 degrees. This was well above the Mile High City’s long term April average of 47.8 degrees.
In terms of precipitation, Thornton saw only 0.66 inches of rain / snow melt. This was far below our 19-year running average for April of 1.68 inches.
Denver, at the airport, recorded 0.50 inches. This too was well below their long term average of 1.68 inches for April.
Snow was similarly disappointing. Thornton only saw 3.2 inches of the white stuff. Our 19-year running average for April is 6.2 inches.
The Mile High City recorded a mere 2.2 inches of snowfall during the month. This was far below the 8.7 inch average for the month in Denver.
Colorado’s famously highly variable weather seems to showcase itself during the month of May when a variety of weather conditions can be seen.
The month can certainly bring extremes.
Snow is not entirely uncommon during the month, occurring in about 50% of Mays. When it does, it has the potential to cause damage to newly bloomed trees.
More common however is severe weather, particularly in the latter half of the month. Thunderstorms become more frequent and their associated hazards – lightning, wind, hail and tornadoes – are usual visitors.
April marks a transition between winter and summer for most of the country but for Denver it is especially true as we can see a stunning variety of weather.
The proverbial April showers are certainly a possibility for Denver. Snow? Tornadoes? Thunderstorms? You bet – all can happen!
For good measure throw in a chance for hail and even dust storms and April gives every type of weather condition you could like – or hate.
Thornton, Colorado’s February 2025 Temperature Summary. (ThorntonWeather.com)
The month of February might have seemed unusually cold and while we did see a very chilly middle of the month, it was bookended by a warm start and finish. Also, while we received a good bit of snow, it was relatively dry giving little measurable precipitation.
The month started out with above normal temperatures dominating six of the first seven days of the month. Things then turned toward the colder side for the next two weeks with below average temperatures on all but one day during the period. We then saw things turn warmer and Mother Nature gave us a hint of spring.
We only saw four days with snowfall, none of which were significant events. All of them were relatively ‘dry snow’ and didn’t do much in terms of liquid precipitation. The greatest snowfall came out the 15th of the month with 3.9 inches.
Overall, Thornton’s average temperature came in at 31.8 degrees. That is right at the running 18-year average for the month.
Our warmest temperature reading of 69.7 degrees came on the 25th of the month. Our coldest, -1 degrees, was recorded on the morning of the 19th.
Out at Denver International Airport where the Mile High City’s official records are kept, it was slightly colder. The site saw an average temperature for the month of 31.2 degrees. This was well below their long-term average for February of 32.7 degrees.
Precipitation for the month was rather meager, despite the snow we received. Thornton saw a mere 0.10 inches in its bucket. This was well below the running average for February of 0.64 inches. It also put February 2025 into the books as the second driest February of the past 18 years.
At DIA, Denver fared better with 0.22 inches recorded. This was just more than half of the long-term February average for the Mile High City of 0.41 inches.
In terms of snowfall, Thornton recorded 6.3 inches. That is a respectable amount but well below our February average of 11.3 inches.
DIA saw less snow than us with 5.5 inches recorded. This was a good bit below their long-term February average of 7.6 inches.
The month of March in Denver is usually one that is welcomed heartily by residents. We begin to shake off the cold of winter with warmer temperatures and calmer conditions. That does not mean we are done with snow and cold by any means.
March usually offers healthy snowfall giving us an opportunity to add to our seasonal totals. While there is good snow potential in March, the month also typically brings much warmer temperatures.
March is historically Denver’s snowiest month and brings about 20% of our annual snowfall. Heavy, wet spring snow storms can oftentimes bring the entire month’s snowfall total in one monstrous snow.
We also start the transition to spring and severe weather season and the month typically brings our first thunderstorms of the year. Temperatures climb throughout the month and by the end our average daytime highs are near 60 degrees.
Thornton, Colorado’s January 2025 Temperature Summary. (ThorntonWeather.com)
It is a running joke that we always see our coldest weather when the stock show is going on. For January 2025, it wasn’t just confined to that couple of weeks as we saw below normal temperatures dominate the entire month.
We started out with a few days of temperatures at or above normal then we turned colder. On the 7th of the month we saw our first snowfall of January. While only a few inches, it got us started on our way to more.
The next ten days were dry and temperatures seemed to moderate a bit. From there, we went downhill.
Two more shots of snow came on the 18th and 20th and we put together a few days of bone-chilling cold. Three days from the 18th to the 20th saw highs well below freezing and four nights with lows below zero.
The rest of the month was quiet, other than some more snow on the 25th. Half of the last ten days of the month saw below normal highs.
Average temperatures for the month in Thornton came in at an even 26.0 degrees. This was well below our 19-year running average for January of 30.4 degrees. It also put January 2025 into the books as the second coldest January over that period.
Our warmest reading of the month was the last day of it at 62 degrees. Our coldest was a -6.0 degree reading on the 19th.
Out at Denver International Airport where the Mile High City’s official readings are taken, temperatures were similar. Denver saw an average temperature for the month of 25.8 degrees. This in comparison to their long-term average for January of 31.7 degrees.
In terms of precipitation, the snow we received was dry, containing little moisture. Thornton recorded 0.30 inches, below our 0.42 inches 19-year running average.
Denver bested us on the precipitation front with 0.56 inches recorded at the airport. This was more than Denver’s long-term average for January of 0.38 inches.
As we mentioned, snowfall was generous with Thornton receiving 10.4 inches. This was well above our January average over the past 19 years of 6.6 inches.
Out at the airport, Denver saw 13.3 inches of the white stuff. That was almost exactly double the Mile High City’s long-term average for January of 6.6 inches.
