Category Archives: Climatology

Thornton’s July 2023 preview: Summer heat really kicks in, thunderstorms common

July

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.

Check out our July weather preview for a complete look at what is in store for the month ahead.

May 2024 Weather Recap: Mild temps, dry conditions and some severe weather

Thornton, Colorado May 2024 Temperature Summary. (ThorntonWeather.com)
Thornton, Colorado May 2024 Temperature Summary. (ThorntonWeather.com)

Most of the month of May 2024 was notable for its mild temperatures and dry conditions. It went out like a lion, however, with a damaging hailstorm.

The first eleven days of the month saw no precipitation at all in Thornton. A few warmer-than-normal days were seen during that period but temperatures were not particularly warm.

Most notable during the first third of the month was the appearance of the aurora. Thanks to some unusually strong solar activity, the celestial event was visible even in the city for a couple of nights.

We finally received our first precipitation of the month on the 12th with a very good, wet event. The next two weeks saw some lighter showers here and there. Temperatures warmed with numerous days seeing readings well into the 80s.

Mother Nature decided to close out the month in dramatic form. Severe thunderstorms arrived around 9:30pm on the night of the 30th, bringing hail up to 2 inches in diameter to the area. Damage was significant and while the rain that came with it was welcome, most residents would have preferred to have gone without.

Thornton ended the month with an overall average temperature of 59.1 degrees. This was well above the 18 year running average for the month of 56.7 degrees. It was the fifth warmest May during that period.

Temperatures ranged from a high of 87.3 degrees on the 17th down to a low of 36.0 degrees on the 2nd.

Out at DIA where Denver’s official measurements are taken, the Mile High City recorded an average temperature for the month of 56.9 degrees, 0.5 degrees below their long-term average. Their highest temperature for the month was 83 degrees on the 29th and their lowest of 30 degrees occurred on the 2nd.

In terms of precipitation, it was a dry one. Thornton saw 1.39 inches fall into its bucket. The majority of that came along with the hail storm on the 30th. That was well below the 1.74 inches average over the past 18 years and puts May 2024 into the books as our driest May during that period.

Denver fared slightly better with 1.70 inches observed at the airport. This was a good bit below the Mile High City’s May average of 2.16 inches for the month.

No snow was recorded in Thornton or Denver during the month.

Click here to view Thornton’s complete May 2024 climate summary report.

Thornton, Colorado May 2024 Precipitation Summary. (ThorntonWeather.com)
Thornton, Colorado May 2024 Precipitation Summary. (ThorntonWeather.com)

April 2024 weather recap: Month sees above normal temps and precipitation

Thornton, Colorado's April 2024 Temperature Summary. (ThorntonWeather.com)
Thornton, Colorado’s April 2024 Temperature Summary. (ThorntonWeather.com)

The month of April was one that did not bring too much drama. While we did see warmer than normal temperatures and a good bit of precipitation, only one snowstorm was particularly notable.

The month started off with some rain on the first and then we entered a dry, mild period. From the second to the 15th, no precipitation was recorded and high temperatures were above average every day of the period.

On the 16th things became more unsettled with some wind and rain. Then, from the 19th and 20th, a spring snowstorm arrived. Thornton received 5.1 inches over the period while Denver bested us with 6.3 inches.

We then saw a few days of dry weather followed by a moisture-laden system that dropped more than an inch of rain on us from the 26th to the 28th.

For the month of April, Thornton’s average temperature came in at 52.1 degrees. This is well above our 18-year running average for April of 48.4 degrees. Temperatures ranged from a high of 82.7 degrees on the 14th down to a low of 28.5 degrees on the 2nd.

For Denver, at Denver International Airport where the Mile High City’s official records are taken, they too saw above normal temperatures. The average temperature for the month there came in at 50.5 degrees versus their long-term April average of 47.8 degrees.

In terms of precipitation, Thornton netted a very respectable 2.54 inches in the bucket. That was a good bit above our running average for the month of 1.74 inches.

Out at the airport, Denver received even more with 3.28 inches recorded. That is well above the Mile High City’s April average of 1.68 inches.

With only one snow event, Thornton’s total for the month came in below average at 5.1 inches. This, in comparison to our 18-year running average for the month of 6.4 inches.

Denver bested us on snowfall as well with 6.3 inches versus their long-term average for April of 6.1 inches.

Click here to view Thornton’s complete April 2024 climate summary report.

Thornton, Colorado's April 2024 Precipitation Summary. (ThorntonWeather.com)
(ThorntonWeather.com)

Thornton’s May 2024 preview: From snow to severe storms

Thornton, Colorado May weather preview.
Thornton, Colorado May weather preview.

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, oftentimes causing 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.

For a complete look at what lies ahead for the month of May, check out our full preview here.

March 2024 weather recap: Temps near normal and an abundance of moisture

Thornton, Colorado's March 2024 Temperature Summary. (ThorntonWeather.com)
Thornton, Colorado’s March 2024 Temperature Summary. (ThorntonWeather.com)

The month of March started off pretty slow with little weather drama and dry conditions. That changed as we got close to the latter half of the month with precipitation in the form of rain and snow taking over.

Through the first 12 days of the month, we had only received 0.6 inches of snow. We had seen a few days of colder temperatures but generally, mercury readings were above average.

That changed on the 13th. A powerful storm system with an unusual setup arrived. We began with a healthy dose of rain in the evening and then, overnight, the change to snow occurred. Heavy, wet snow fell on the 14th throughout the day and into the evening. Schools and many businesses closed down for the day. Thornton saw 10.8 inches of snow and a whopping 1.73 inches of liquid precipitation.

We then strung together nine days of calm, dry conditions. On the 25th, snow returned although it wasn’t anything too dramatic. Thornton saw 4.4 inches of the white stuff. The month then closed out with temperatures not far from average.

Overall, Thornton saw a monthly average temperature of 42.4 degrees. This was just above our running 18 year average of 42.0 degrees for the month of March. Mercury readings ranged from a high of 71.8 degrees on the 2nd down to 16.8 degrees pm the 26th.

For the Mile High City, where Denver’s official records are taken, they saw an average of 41.4 degrees. That was just slightly cooler than their long term March average of 41.2 degrees.

Liquid precipitation was abundant for the month with Thornton seeing 2.32 inches, most of which came with the storm on the 13th and 14th. This was well above our March average of 1.30 inches.

Denver recorded 1.65 inches in their rain bucket. This too was well above their March average of 0.86 inches.

Snowfall was above average as well. Thornton saw 15.8 inches in March 2024. This easily bested our March average of 11.3 inches.

Our at the airport, Denver saw a mere 9.2 inches. This was a bit above the Mile High City’s long term average for March of 8.8 inches.

Click here to view Thornton’s complete March 2024 climate summary report.

Thornton, Colorado's March 2024 Precipitation Summary. (ThorntonWeather.com)
Thornton, Colorado’s March 2024 Precipitation Summary. (ThorntonWeather.com)

Thornton’s April 2024 weather preview: Winter, spring and summer all in one month

Thornton's April weather previewApril 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.

Last week’s snowfall totals from the storm highlight an ongoing issue

Denver's March 14 & 15, 2024 Snowfall Totals. (National Weather Service)
Denver’s March 14 & 15, 2024 Snowfall Totals. (National Weather Service)

We all know our Pi Day storm last week was a big one.

Here in Thornton we recorded 10.8 inches. Downtown Denver reported 12.2 inches.

What will Denver’s official snow records show? A mere 5.7 inches. This is a direct result of the National Weather Service’s insistence on having Denver’s official measurements taken at Denver International Airport.

Data was collected in downtown Denver from 1872 through December 1948, then at the Stapleton Airport Office from January 1950 through February 1995. In March 1995, the service made the station at DIA the city’s official station for most meteorological observations. In 2008, they began taking official snowfall measurements out there.

Being so far from the Mile High City’s population center, the data collected there is entirely unrepresentative of what residents experience. Further, the move has skewed our climate records rendering comparisons to historical data invalid.  It is highly frustrating and is a significant issue which the National Weather Service dismisses.

Local television meteorologists have long railed against the change in station, most notably Mike Nelson of Denver 7. With this storm, Ashton Altieri of CBS 4 called the National Weather Service out on it.

February 2024 weather recap: Much warmer and wetter than normal

Thornton, Colorado's February 2024 temperature Summary. (ThorntonWeather.com)
Thornton, Colorado’s February 2024 temperature Summary. (ThorntonWeather.com)

The past month was one that started out with some excitement in the form of snow (after rain) but then became far calmer and warmer.

On the third of the month, we saw a system move in that initially offered precipitation in the form of rain, and a good bit of it. That eventually transitioned to snow giving us 3.2 inches. Our biggest snowfall of the month of 4.2 inches followed on the 10th. We then saw a few other, smaller snowfalls, enough to put the month above average in terms of snowfall and precipitation.

Temperatures never really got all that cold. There was only one single digit reading for the month, less than you would expect and, particularly toward the latter part of the month, spring-like mercury readings were pretty common.

Thornton’s average temperature for the month came in at 38.5 degrees. That was far above our 18 year running average for February of 31.8 degrees. That put February 2024 into the books in a tie with February 2016 for the second warmest February. Number one is February 2017 at 40.1.

Out at Denver International Airport where the Mile High City’s official measurements are taken, the month saw an average temperature of 37.6 degrees. That too was well above their long term average for February of 32.7 degrees.

Temperatures in Thornton ranged from a high of 68.6 degrees on the 20th down to a low of 8.9 degrees on the 17th. Denver twice saw its warmest reading of 65 degrees and its coldest reading was 7 degrees.

Precipitation was bountiful, not only due to some decent snow but mainly due to the rain on the third. Thornton saw 1.67 inches of liquid precipitation for the month, a full inch above the 18 year February average of 0.67 inches.

Denver was drier, but not by a lot. The airport recorded 1.46 inches of liquid precipitation. This versus the Mile High City’s long term February average of 0.41 inches.

In terms of snowfall, we lacked any big storms but the littler ones added up. Thornton recorded 11.8 inches of the white stuff, just above the 18 year running average of 11.6 inches.

Denver bested us on the snowfall front recording 13.7 inches, well above their long term February average of 5.7 inches.

Click here to view Thornton’s complete February 2024 climate summary report.

Thornton, Colorado's February 2024 precipitation Summary. (ThorntonWeather.com)
Thornton, Colorado’s February 2024 precipitation Summary. (ThorntonWeather.com)

Thornton’s February 2024 weather preview: Temps begin to warm, snow can be elusive

February in Colorado typically brings to an end an extended period when average temperatures are at their lowest. Winter begins to loosen its grip and temperatures get warmer but precipitation is not a particularly common event during the month.

Thus far, our snow season has been a bit of a disappointment and while January brought some of the what stuff, it wasn’t a lot. February is only our sixth snowiest month so we can’t count on much else.

Temperatures however do usually see a nice rebound during the month. Average high temperatures climb from an average of 44 degrees at the start to 50 degrees by the end of February.

For the complete February preview including a look at historical averages and extremes as well as a look at what long range forecasts are predicting, click here. 

January 2024 weather recap: Some extreme cold, some very pleasant weather

Thornton, Colorado's January 2024 temperature summary. (ThorntonWeather.com)
Thornton, Colorado’s January 2024 temperature summary. (ThorntonWeather.com)

The month of January offered a bit of a mixed bag of weather, showcasing the kinds of extremes our weather is known for. While we saw a period of bitter cold, the month ended with a string of mild days.

The first few days of the month were nice enough, with calm, dry conditions and temperatures above normal. From there, we entered a period dominated by colder than normal mercury readings. Most notable, Arctic air that arrived on the 12th and sent the thermometer down.

The following three days saw highs only in the single digits and four mornings with below zero lows. During that period we also received our most notable snowfalls of the month although they did not amount to much. Thornton received 1.8 inches on the 13th and 2.5 inches on the 15th.

The last half of the month saw things turn warmer with above normal readings for the final 10 days of the month. The last four days were very nice with readings of 60+ degrees.

In the end, Thornton’s January 2024 average temperature came in at 28.7 degrees. That was 1.9 degrees below our running 18-year average for January of 30.6 degrees. Temperatures ranged from a high of 62.5 degrees on the 28th down to a low of -12.2 degrees on the 16th.

Out at Denver International Airport where the Mile High City’s official measurements are taken, they saw an average temperature for the month of 28.2 degrees. This was well below their long term January average of 31.7 degrees.

January is rarely a wet month and it was not in 2024. Thornton saw a mere 0.25 inches of snowmelt. This was a good bit below our January average of 0.42 inches.

Denver received more precipitation than us, but not by much. They saw 0.28 inches in their bucket, a good bit below their January average of 0.38 inches.

Snowfall for the month was respectable but as indicated above, dry. Thornton had a January total of 5.4 inches. This was 0.9 inches below our 18-year average for January of 6.3 inches.

Out at the airport, Denver saw less than us recording only 3.6 inches. This was well below the Mile High City’s January average of 6.4 inches.

Click here to view Thornton’s complete January 2024 climate summary report.

Thornton, Colorado's January 2024 precipitation summary. (ThorntonWeather.com)
Thornton, Colorado’s January 2024 precipitation summary. (ThorntonWeather.com)