Category Archives: Climatology

Thornton’s September 2022 preview: One of our more pleasant, calm months usually

Following an August that was unseasonably warm and dry, 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.

Get a complete look at September’s weather and more details as to what we can expect this year here.

June 2022 in Thornton saw average temps, drier than normal conditions

Thornton, Colorado June 2022 Temperature Summary. Click for larger view.
Thornton, Colorado June 2022 Temperature Summary. Click for larger view.

Last month was one of relatively little drama. Normally we expect June to bring plenty of severe weather but that just was not the case this year. That was, in part, due to a lack of moisture.

Thornton saw only 0.52 inches in the rain bucket, well-below average. While we did see some hot temperatures (two 98 degree readings being tops), overall the monthly average temp came in right near Thornton’s running 16 year average.

See the monthly climate summary for details.

Thornton, Colorado June 2022 Precipitation Summary. Click for larger view.
Thornton, Colorado June 2022 Precipitation Summary. Click for larger view.

Thornton’s July 2022 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.

Thornton’s June 2022 weather preview: Warmer temperatures, increased severe weather

Thornton's June weather preview.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.

Read more about Thornton and Denver’s June weather and a look ahead at this year.

Thornton’s May 2022 preview: From snow to severe storms

Thornton, Colorado May 2013 weather preview.
Thornton, Colorado May 2013 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.

Winter-like temperatures and snow are possible as are mid-summer like temperatures or the more typical spring severe weather.

As the month starts out in 2022 we are going to enjoy some much-needed precipitation. Long range forecasts however portend a potentially drier than normal month.

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.

Denver breaks high temperature record for April 22

Record High Temperature

We knew it was going to be extraordinarily warm and blustery today, particularly for April. The numbers bear it out as Denver set a record high temperature for the date, one that also tied for the second warmest April reading on record.

As measured at Denver International Airport, the Mile High City topped out at 89 degrees. That bests the previous record high for April 22nd of 88 degrees set in 1989. The reading was also the second warmest April temperature recorded in Denver history coming in second to a 90 degree reading on April 30, 1992.

Here in Thornton we were just a hair cooler with a high of 88 degrees.

Severe Weather 101 – Tornadoes and tornado safety

Last year's Windsor Tornado highlights the very real danger twisters present in Colorado. Do you know when to do when one strikes?
The 2008 Windsor Tornado highlights the very real danger twisters present in Colorado. Do you know when to do when one strikes?

One fact that may surprise those new to Colorado is that we are actually on the western edge of the infamous Tornado Alley. This large swath of land comprises much of the nation’s midsection and is a unique place as the United States sees more tornadoes than any other place on earth. In fact, tornadoes have been recorded in all 50 states including Alaska and Hawaii.

Closer to home, Colorado sees our share of these storms. In fact, one metro area county – Weld County – holds the distinction of being the “tornado capital of the world.” With 252 tornados from 1950-2011, no single county in the nation has had more tornadoes! Adams County is number two in the state and isn’t far behind with 156 over that same period.  Granted these numbers are skewed a bit simply due to the sheer size of those counties, but it does serve to highlight the real danger that tornadoes present.

Even here in the metro area tornadoes are a real danger. The Thornton area was struck in 1981, one of the worst tornadoes to strike the Denver area in history. At 2:30 p.m. this tornado touched down and by 2:45 p.m., the tornado had hit Thornton City Hall. The tornado’s destruction sent 53 injured people to hospitals, 25 homes were destroyed and 239 structures were damaged.

One common myth is that tornadoes don't strike metropolitan areas. This has been disproved many times including here in Colorado in 1982 when an F2 tornado struck Thornton. Image courtesy the City of Thornton archives.
One common myth is that tornadoes don’t strike metropolitan areas. This has been disproved many times including here in Colorado in 1981 when an F2 tornado struck Thornton. Image courtesy the City of Thornton archives.

The most well known tornado outbreak in the metro area occurred on June 15, 1988. Five tornadoes resulted in seven injuries and damage in excess of $15 million.

We all of course also remember in 2008 when the town of Windsor, not far from Denver, was struck with an EF-3 tornado that claimed one life and destroyed and damaged hundreds of buildings.

The greatest threat for tornadoes occurs during late spring and early summer when you have a combination of heat and moisture in the lower atmosphere. Here in Colorado, tornadoes are frequent from May through August with June being the most active month.

However, there is no hard and fast rule for when tornadoes strike, as Colorado witnessed on March 29, 2007 when Holly, Colorado was struck by an EF-3 tornado with winds of 165 mph. Two women lost their lives as a result of that event and 160 homes were damaged.

Colorado ranks 10th in terms of the number of tornadoes with 1,911 events from 1950-2011. One good thing is that our high altitude and drier air do make it harder for the monster supercells that spawn the biggest tornadoes to form. Most of our tornadoes are small and short lived. Further, thanks to the wide open spaces of the eastern half of our state, many strike sparsely populated areas. This is reflected in the fact that we rank 38th for tornado related deaths.

Continue reading Severe Weather 101 – Tornadoes and tornado safety

Thornton’s April 2022 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.

Denver smashes record low temperature for March 10

Record Cold Temperatures

Old Man Winter isn’t done with the Mile High City just yet as evidenced by the bone-chilling cold this morning.

As measured at Denver International Airport, Denver’s low temperature plummeted to -7 degrees this morning. That easily bests the previous record low for March 10th of -3 degrees set in 1932.

Additionally, it puts March 10, 2022 into the books as being one of the top 10 coldest March temperatures on record and is the Mile High City’s coldest March reading since 1960.

Here in Thornton, we managed to escape getting quite that cold. We saw a low of 0 degrees at 4:12am.

Denver ties record high temperatures for March 2

Record High Temperature

Temperatures like this are sure to bring an early onset of spring fever as Denver tied the record high temperatures today.

As measured at Denver International Airport, the Mile High City topped out at 74 degrees. This ties the record high for the date last set in 2009.

Here in Thornton, we stayed cooler, topping out at 71 degrees.

More mild, potentially record setting, weather will be on tap tomorrow. Then, we see a return of wintry weather for the weekend and into next week.