Boulder’s First Snow: When the Flakes Usually Fall

Ask any Boulderite, and they’ll tell you that one of the city’s charms is its unpredictable weather. One day you’re in shorts on a sun-splashed patio, and the next you’re brushing snow off your windshield. That mix of sunshine and snow is part of Boulder’s personality, and it’s why the date of the city’s first snowfall is always a hot topic around town.

What the Records Show

Official records from the National Oceanic and Atmospheric Administration (NOAA) track Boulder’s first measurable snow—anything more than just a trace—back to 1948. Over those decades, the average first snow date lands on October 17. But averages only tell part of the story.

• Earliest recorded snowfall: September 12, 1974

• Latest recorded first snow: November 17, 2016

• Typical range: Late September through late October

That wide spread shows just how variable Boulder’s seasons can be. Some years, residents see snow dusting the Flatirons before the leaves have finished turning. Other years, locals are still riding their bikes in shorts well into November before the first flakes fall.

Outliers: Snow in September and Snowless Octobers

Extreme cases make the story even more interesting. In 2020, Boulder saw an incredibly early measurable snowfall on September 8, dropping 1.7 inches just days after a record heatwave. On the other end of the spectrum, 2016 kept everyone waiting until mid-November for the season’s first snow. These swings highlight the unique weather patterns caused by Boulder’s elevation, proximity to the Continental Divide, and the frequent arrival of warm Chinook winds that can melt a snowpack in hours.

Why It Matters

For Boulder’s community, the arrival of the first snow is more than just a statistic. It signals the start of ski season excitement, a rush to get tires swapped out, and the first evenings gathered around fireplaces. Businesses, too, pay close attention. Outdoor retailers, coffee shops, and ski rental stores see a surge in customers once the first flakes arrive.

There’s also a cultural element: students at the University of Colorado Boulder often mark the first snow with spontaneous snowball fights on campus. Families take walks to see the Flatirons dusted white, and photographers flock to Boulder Creek to capture the mix of golden leaves and fresh snow.

Boulder’s First Snow in Perspective

Looking at over a century of weather data, one thing is clear: Boulder’s first snow rarely sticks around for long. September and October storms often melt within a day or two, offering just a taste of what’s to come. The “real” snow season doesn’t settle in until later, but that first dusting is always celebrated as the unofficial kickoff to winter in the Rockies.

So whether it’s an early surprise in September or a delayed debut in November, Boulder’s first snow is more than a weather event—it’s a tradition, a conversation starter, and a reminder of how this mountain town keeps everyone guessing.

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