The truth about winter in Denver

Editor’s note: This story originally appeared in RED in October 2018 and has been edited to ensure that all information is up to date. 

New to Denver and bracing for your first winter at 5,280 feet above sea level? Richard Wagner, Ph.D., and Sam Ng, Ph.D., professors of Meteorology at Metropolitan State University of Denver, offer a primer on what to expect.

Denver winters are quite mild

If you’re planning to pack a polar face mask and Mount Everest-ready mittens for a winter trip to Denver, you might want to rethink your wardrobe. While it can get decidedly chilly sometimes, overall temperatures during the winter months are moderate. “Even the coldest month, December, has an average daily high temperature of 45 degrees, and days reaching 60 degrees are fairly common,” Wagner said.

For a realistic snapshot of what Colorado winter weather looks like, just watch a Denver Broncos home game on TV and check out the crowd. Even in January, you’ll often see the fans wearing short sleeves or a light jacket. And that’s because a nice winter’s day in Denver feels like a cool spring day in many other places.

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Our winters start early and end late

Denver residents generally first see snowfall in mid-October — earlier than any other major city in the U.S. — and are usually still clearing the fluff from their driveways in late April.

And despite the gradually warming climate, the snow still occasionally hits Mile High sidewalks as early as September and did so just three years ago, in fact. But early snow really peaked in the late ’90s.

“Denver’s official records show that for five years during the ’90s, we had measurable snowfall in September,” Wagner said. And many locals still remember September 1985 with a shiver: That’s when a massive 8.7 inches of snow fell amid deeply unseasonal temperatures as low as 17 degrees.

When it snows, it really snows

Denver averages 57 inches of snow a year, which sounds relatively modest, especially when compared with the 300-plus inches that fall on the nearby Rocky Mountains. But when a snowstorm does hit town, it can drop the kind of huge, thick blankets of snow that could easily bury a small dog. And if anything, those storms are growing bigger.

“Over the past 20 years, we’ve seen more of these huge dumps of snowfall hitting Denver, sometimes more than a foot and a half in a single storm,” said Wagner. “The biggest snows generally arrive early in the season during October or much later in March or April. But even the smaller January storms are now getting deeper.”

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El Niño could mean even more snow this year

For the first time in a while, warm Pacific air currents will impact how Denver experiences winter this year. And according to Ng, that could translate into an extra deluge. “With El Niño, you often see a couple of very big snowstorms — real humdingers, with the snowfall hitting double-digit inches — during the early and late winter periods,” he said.

Such downfalls can be, well, prodigious. “Sometimes, these blizzards drop so much snow that even one or two of them can bump up the city’s average snowfall levels,” Ng said. Still, as every Denverite knows, snow does not stay long in this city. The Colorado sun is so powerful that even a heavy snowfall usually melts away in a day or two.

Denverites probably won’t see warming benefits of El Niño this winter, because any hotter-than-normal temperatures are likely to pass farther north. That should mean more temperate winter weather throughout the upper Great Lakes states and the Pacific Northwest but not, sadly, around the Mile High City.

“We’ll be missing out on the fun weather, I’m afraid” Ng said. “According to the National Oceanic and Atmospheric Administration, this year’s overall winter outlook for the Denver metro area is trending toward near-normal temperatures and above-average precipitation.”

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Our snowiest month may surprise you

Which month sees the most snowfall in Denver? You might guess December or maybe January. You probably won’t be thinking of March, nearly half of which, after all, is technically spring. And yet statistically, with an average snowfall of 11.4 inches, March is Denver’s snowiest month. “Climatologically, the snowiest week of the year is the last week of March,” Wagner said. “And something else that might surprise people: The second-snowiest time of the year is the first week of April.”

However, March snowfall is wildly unpredictable, which means Denverites never quite know what to expect. Some years, there is almost too little snow to measure, then in other years one or two big storms will bring a blizzard. The record year was 1944, which saw 32.5 inches — almost three feet of snow.

The “300 days of sunshine” myth

It’s Denver’s unofficial slogan and features in virtually all of the city’s tourist and promotional materials. The only thing is: It’s not really true. Denver’s claim to “300 days of sunshine” was first made in the 1870s by a railroad-company publicist, and the city has pretty much run with the line ever since. But the only way to actually reach that total is by counting a single hour’s sunshine in 24 hours as a “sunny day,” which obviously is cheating.

However, Denver does enjoy a beautiful climate throughout most of the year that is the envy of many other U.S. cities. And if you are thinking of visiting in winter, Wagner has an important piece of advice: “Invest in good sunglasses. All those powerful UV rays from our sunny skies bouncing off the white snow is not good for your retinas.”