As we have grown to expect in Colorado, the weather events that occur here are pretty wild and always have people talking. The “fun” aspect to the weather here is that you can get so many extremes – whether good or bad – that highlight just how unique the weather can be across the state. From the Plains to the alpine tundra to the deep canyons, Colorado delivers the drama and we love to live through it. Here’s a not-all-inclusive list of the top weather events in Colorado in 2021 – in no particular order. What do you remember the most?
Smoke Plume Delivered Denver the World’s Worst Air Quality
Although Denver didn’t have as intense of a fire season like 2020, the city had arguably worse air quality this year thanks to fires to the west of us. There were more than 120 days of bad air quality in Denver and around Colorado this summer making it another summer of smoke. The smoke was so thick at times that the view of the mountains from I-25 disappeared. Denver is no stranger to air quality issues but this summer brought such bad air at times that we topped the global list of cities with bad air quality.
Wettest Springs on Record – Denver Cloudier than Seattle
The first 5 months of 2021 were great in terms of rain and snow. A huge March snowstorm and a very active monsoon season lead to Denver experiencing so many cloudy days and so much moisture. At one point this year, Denver had more cloudy days than Seattle and had gotten more precipitation than Miami. The active start to the year brough Denver out of drought and greened up the landscape beautifully as Spring ended and Summer started.
Hot and Dry Summer
In an almost literal flick of the switch, Denver and Colorado went from one extreme to the opposite. This summer (June through August) was the third warmest on record, behind 2020 and 2012. The city saw the third most 90-degree days on record and was in the top 5 for driest summers on record. For many east of I-25, the last time appreciable precipitation accumulated happened in June. This heatwave was the start of the dry period that has led this area of the state back into drought.
Historic March Blizzard
March 13-14 will be remembered by many for years to come. That’s thanks to an epic snowstorm that slammed NE Colorado with some of the area’s biggest snowfalls ever recorded. The March blizzard buried Denver in over 27-inches of snow making it the fourth biggest snowstorm to ever impact the city. This also lad to March being one of the wettest and snowiest March’s in history bringing much of the region out of drought status.
Long-lived and Intense Heatwave
Winter slowly transitioned to Spring in Denver but the transition to summer was ultra-fast. The second week of June brought an intense heatwave to the region. Denver endured record-breaking 100-degree heat several days in a row and this wasn’t localized to Denver. Grand Junction recorded its hottest June temperature ever and Colorado Springs recorded record-breaking-triple-digit heat as well.
Landspout Tornado Seen Across the Front Range
The jaw-dropping landspout tornado that happened in early June was quite the spectacle. A huge, towering column of spinning air was seen by folks up to 70 miles away thanks to a combination of weather conditions. This landspout tornado had to be one of the most widely documented weather occurrences this year. It’s estimated that this tower of dirt and dust was 10,000-feet high.
Monsoon Season – 2021 – the Summer of the Slides
Rain and more rain and more rain. That was the story for a while this summer as monsoon downpours impacted Colorado in a major way for the first time in years. The summer of 2020 brought devastating wildfires and a lack of rain which created the perfect conditions for mudslides and burn scar flooding and that’s exactly what happened. I-70 in the Glenwood Canyon closed multiple times in July due to rock and debris flows that damaged large chunks of the highway. This year, more flash flood warnings were issued in Colorado than any year before.
Latest Snow on Record
Denver usually sees the first snow in mid-October. In 2020, Denver and the Front Range had one of its earliest snow on record with measurable snow falling in early September. This year however, the Front Range had to wait for snow and the wait was excruciating. Denver officially recorded the first snow of the season on December 10th – the latest date of first snow by more than 2 weeks. Only 0.3″ of snow fell on the city so it wasn’t even that exciting. Much of the Front Range had to wait an abnormal amount of time for their first snow as well.
Driest and Warmest End of the Year
The year started out a bit lackluster in the precipitation department but quickly changed in March after the blizzard. We had a surplus of moisture since March and our surplus was so good that it lasted all the way through September. Precipitation really shut off in July and has yet to return in any significant way. The last 6 months of 2021 have been Denver’s warmest by almost a full degree, they’ve been the least snowy by almost 3-inches and they’ve been the driest ever by more than an inch. We’ve been running a deficit in our annual precipitation since late-September and that is the reason why Denver and the surrounding areas are back in awful drought. Again.
Last Breath Mega Holiday Snowstorm(s)
The all-so-important snowpack in Colorado was a little temperamental at the beginning of this water snow season. October delivered great snows that brought snowpack above average but the state saw virtually no snow through November and early December. Snowpack was way below average as the year was coming to an end which had a lot of people worried about the rest of the season. Thankfully, in expected Colorado fashion, things turned around rapidly. A series of storms hit the state delivering several feet of snow around the Holidays and bringing snowpack to near or above average statewide.
Of course there was so much weather that happened this year that not everything made the list but there were some honorable mentions:
Mid-December wind and dust storm across eastern Colorado
An extremely strong storm racing over our area from California blasted the state with intense and damaging winds and stirred up so much dust that roads were shut down at times due to low visibility. Over 100 mph winds hit areas between Denver and Colorado Springs. Tens of thousands of customers were without power because trees and limbs fell.
Denver doesn’t get 300 days of Sunshine
The advertised 300 days of sunshine Colorado and Denver boasts are simply not true. Due to a convoluted tracing system for cloud cover, there’s no legitimate way to prove we have 300 days of sunshine. If you average the number of clear or sunny days in Denver per year you get about 110 days of clear skies. Far less than the advertised 300.
New Climate Normals
Climate normals are extremely important to track when talking about climate change and weather normals for a select area. In order to have extremes, you have to have normals. Normalizing data for temperature and precipitation uses 30 years of information. The normals we used between 2011 and 2020 were based on data from 1980-2010. This year, that data got update and the changes were notable. All of Colorado has warmed since the last update and nearly every part of Colorado has seen a drying trend as well.
What weather do you remember most from this year?