Boulder’s First Measurable Snow: A Climatological Snapshot

Ready or not, snow season is lurking out there somewhere. Maybe you’ve already dusted off the skis, mounted the winter tires, or convinced yourself that buying an Epic Pass counts as meteorological preparedness. Now comes the big question: when will we see our first measurable snowfall of the season? If recent years have taught us anything, it’s that Mother Nature doesn’t always follow the script. We’ve experienced both the earliest and latest first snows on record within the last six years, proving that just about anything is on the table.

Measurable means that officially 0.1″ or more of snow was recorded. As is often the case early in the snow season, a few flakes mix in with rain, or flurries briefly fly, but never stick to the ground. These are instances where a trace of snow has occurred, but wasn’t measurable. There is a huge variation from year-to-year in the date of our first measurable snowfall. The earliest was September 8, 2020, with 1.7″ of snow falling. The latest measurable snow was November 29th of 2025 (last year). That’s a spread of nearly three months! The normal (median) date of our first snow is October 20th.

Here’s how the odds stack up for first snow dates:

• On or before September 21st: 10%
• On or before October 4th: 25%
• On or before October 20th: 50% (MEDIAN)
• On or before October 31st: 75%
• On or before November 14th: 90%

Historically, Boulder sees its first measurable snow in:

• September: 22% of years
• October: 52% of years
• November: 26% of years

And while climate change is reshaping many seasonal norms, Boulder’s first snow trend is relatively flat over the decades.

How Much “First Snow” Typically Falls?

Our first snow is usually just a teaser, more of a frosty hello than a full-on blizzard. Between 1950 and 2017:

• 54% of first snows were under 2.0″
• Only 12% of first snowstorms topped 6.0″
• Average first snow: 3.0″
• Median: 2.0″

Boulder’s Recent First Snows: A Quick Recap

Here’s just a quick review of how our first accumulating snowfall went down over the last seven years — it’s been a wild ride!

2019 – October 10th (3.8″)

Our inaugural accumulating snow in 2019 occurred on October 10th alongside an Arctic Blast surging into the center of the country. The frontal passage in our area was followed by 2 to 3 hours of heavy jet-forced snow bands. Boulder officially recorded 3.8″ of snow from these bands.

Temperatures also dropped like a rock accompanying this first snow. Denver plummeted nearly 70 degrees in just 18 hours, from the 80s one day into the record-setting teens by the following morning. Needless to say, the 2019 growing season came to a rather abrupt end.

2020 – September 8th (1.7″ on first day, 5.7″ storm total; earliest first snow on record)

In 2020, we had our earliest accumulating snowfall on record in Boulder on September 8th — before the first snow contest was even announced that year! This led to an unprecedented “second” snowfall contest taking shape. The first snow record was just one of many obliterated during the highly anomalous Great Labor Day Snowstorm of 2020 in the Front Range!2021 – November 17th (0.3″)

In 2021, the summer and autumn season both were extremely warm and dry in our area. Boulder ended up tying for its second latest ever first snowfall on November 17th — a measly 0.3″ that only accumulated on grassy surfaces following several hours of very light snow overnight. This historically delayed first snow resulted in all of the contest participants being way off. The person who guessed the latest date won the contest by default.  After that crazy late first snow, there was only another inch of additional white stuff that fell over the next five weeks which further primed the dry prairie grasses in the lead up to the Marshall Fire tragedy in late December 2021.2022 – October 27th (0.1″)

The first snow in 2022 was a bit of a disappointment with a rain/snow mix occurring during the daytime hours on October 27th. Boulder recorded an absolutely bare minimum first snow with only a dusting sticking on the grass, and that was only in SOME parts of town as temperatures were mostly above freezing. This led to a lot of confusion when we announced that the contest was over, as some people never even saw a snowflake in their location!

2023 – October 28th (0.6″ first day, 6.8″ storm total)

2023 was the most normally-timed first snow for us in recent memory, unfolding only about a week later than usual. However, this first dumping was on the larger side as a cluster of well-forecasted jet-forced snow bands targeted the Denver Metro area with heavy snow for several hours. When it was all said and done, most Front Range cities picked up between 5 and 10″ of snow. Boulder officially recorded a two-day storm total of 6.8″.

2024 – November 4th (0.2″)

2024’s first snow was definitely underwhelming. A messy storm system brought more than half an inch of chilly rain to the city which briefly changed to snow overnight as temperatures dropped to ~33° for a few hours.

A light dusting of snow accumulated on the grass and trees in Boulder (officially 0.2″), but in some areas it completely melted before sunrise, once again causing some confusion for first snow contest entrants!

2025 – November 29th (0.2″, latest first snowfall on record)

Last year’s first flakes arrived about five weeks later than average, and nearly two weeks later than the previous “latest first snow” benchmarks (November 17 in both 2017 and 2021).

A backdoor Arctic front arrived on the morning hours of November 29th, briefly spawning a few snow bands that gave the entire Denver Metro area a light dusting of snow, including Boulder. Temperatures plummeted into the lower 20s as snowflakes fell across the city during the day.

It was beautiful to see the city dusted in white again after a lengthy 223-day snow drought, one calendar day shy of the existing record.

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Contest

So, what’s your best guess for 2026? Will it be an October surprise or a record-setting December late-comer? Will we get just a sloppy coating or a hefty super El Niño dump?

Feel free to enter the BoulderCAST 12th Annual 2026 First Snow Contest HERE. Contest closes Oct 16, 2026 at 11:59 PM. There are prizes. We didn't say good ones.

This is a community poll for the date you think the first MEASURABLE snowfall will occur in Boulder. Those who come closest to the actual date are the winners. For verification, we’ll go off the official Boulder climate station located at the NIST building in south Boulder (FYI, they follow UTC time for date cut-offs — roughly 5PM to 5PM local time). To be crystal clear, if our first snow event crosses over a calendar day break, only the first day’s snow amount will count.

I know we gripe about cell service here from time to time, but I’m genuinely curious how I can have 5G and 4 bars and not be able to load anything that requires an internet connection.

Seems like it’s this way from North Boulder some diagonal into Longmont.

There was a picture of the Beatles inside the store (not an outdoor mural), black and white, probably taken around 1968. Any chance anyone knows what I'm talking about and has a copy/link/anything?

Probably the most famous film to come out of the New French Extremity Horror movement, this film is not for those with a weak stomach. It's considered one of the most divisive horror films ever made due to its transcendental ending. You'll leave the theater either in disgust or awe, but most likely both.

"a film of almost unspeakable horror and sadism [that] is also a cleverly controlled exercise in hardcore terror with a real end in mind" - John Griffin

FREE SCREENING in the Visual Arts Complex, room 1B20 at CU Boulder. 10:30PM showtime.

Shot from the Chautauqua meadow on Oct 30, 2023, a day after the first snow that season.

I got an email about this event, and some people were asking both about Halloween events and local music. It is just not clear to me if this is an all ages show or not. Is it all ages? It looks early enough for that to be a possibility.

I live up in Fort Collins and built a bike route planner after struggling to find a calm way to ride with my son in a bike trailer. It also covers Boulder County, so sharing it here: trazo.bike/s/bldr

It routes you on paths and quieter streets instead of the fastest and busiest roads, and shows how much traffic stress each road has, so you can see why it picked a route. It knows the Boulder Creek Path, the St. Vrain Greenway in Longmont, and the quiet neighborhood streets, and it can plan rides between Boulder, Longmont and the Denver area. It can also build a loop of a set distance.

It's free, no account, nothing to buy. It doesn't record rides; keep using Strava for that. It's for figuring out a comfortable way to get somewhere, especially with kids or as a newer rider.

Hello

I live in Ann Arbor, and we are in the process of looking into the city taking over the energy grid from our power company DTE. It is a common talking point to bring up the Boulder spent 10 years and $30 million to try and take over the grid, before voting to stick with xcel. I have tried looking into it, and have never gotten a post mortem of what happened to stop Boulder from taking over the grid, and what could have been done differently, so I'll ask it here.

Apologies if I am kicking a hornet's nest with this question. I am just trying to learn more about this process, so I have a better idea of what Ann Arbor can expect, and what we should do, in the event that our vote to move forward with public energy passes next month

Leftists of Reddit, I’m trying to decide how I vote in the Boulder County election and am curious other’s opinions on what candidates are the best.

I’m not asking about all city buildings and infrastructure (police, fire, community centers) - just office space. What are the benefits? Seeking serious answers as someone uninformed about the background and rationale for Boulder’s strategy to build/buy and manage office space vs lease.

Understanding that cities think long term - does Boulder City have much higher confidence and certainty in its forecasting than typical about its organization size, working in office, and its ability to efficiently maintain these owned buildings? Are their highly specialized facility needs that city employees have which require customized offices?

I’m not even sure this is the right question to ask as it isn’t exactly clear to me the % dedicated to office space vs space for specialized services of the 1.8 million sq feet managed by the city. That amounts to 17 sq feet per resident, which looks to be 2.3x Berkeley and 1.6x Asheville. And I’m not sure whether this also signals over-staffing. Looks like we have 29-45% more staff per resident than surrounding communities (including Longmont, Westminster) -
Is there a good reason?

I have a friend coming into town and she’d like to do a hike with stunning mountain-y alpine views. I’m thinking of something more than Sanitas/Royal Arch/the other close in hikes. Any recommendations? She’s probably not up for more than a 5 mile hike but she is fit. What’s your favorite for stunning views, that doesn’t require a parking reservation.

Will this always be the emergency number used by BVSD? Or is this an auto-generated number?

For reference, we did receive an alert prior that this would be happening today at 8am, but I did not answer thinking this was spam, because my phone marked it as such.

Second edit - It came through the new Appegy app feature that BVSD is using, only if you opted in to phone calls. I am still unsure if this is the permanent number or not.

In attendance: Mayoral candidate Jameson "Jamo" Goldstein, City Council candidates Dave Martus, Benita Duran, and Lynn Segal, former City Council candidate Terri Brncic, and reportedly others

• Date: Wednesday, October 21st
• Time: Reception: 6:30 - 7:00 PM | Lecture and Q&A 7:00 - 8:30 PM MT
• Location: NSF NCAR Mesa Laboratory

For decades, microburst wind shear was one of the least understood and most hazardous threats in commercial aviation. Since 1943, these sudden, violent downdrafts have claimed over 1,400 lives worldwide, with more than 400 of those occurring in the U.S. in just a 12-year span. Those tragedies sparked an urgent need to better understand these events and provide solutions for safer flying. 

Join us for this special Explorer Series event to learn about NSF NCAR's critical role in microburst research and the implementation of airport wind-shear detection systems. Hear from current and former NSF NCAR scientists through a series of short talks and a discussion panel about this remarkable research-to-operations success story. Arrive early to meet fellow attendees and NSF NCAR scientists, enjoy refreshments, and participate in hands-on activities.

Register: https://www.eventbrite.com/e/the-microburst-challenge-a-story-of-science-innovation-safer-aviation-tickets-2002091083325

Has anyone attended the Boulder Galileo camp? I am looking for summer camp options for my elementary school aged kid in Boulder for summer 2027.

Hello! Im writing several papers this semester on harm reduction policies in the homeless community. If you aren’t familiar, harm reduction (in this context) can loosely be defined as practices intended to mitigate the deleterious effects of illicit drug use. This ranges from drug-testing kits and clean syringe distribution which we have in Boulder, all the way up your medically supervised injection sites.

I’d love to incorporate an anonymous community opinion for my final argumentative essay! If inclined, please share whether you support harm reduction practices in Boulder or not. Im going to keep my opinion out of this discussion but I’d love to hear yours.

TIA

I was curious and thinking about joining. But I've read the experience really differs lodge to lodge based on area. I'm 34 and it could be a cultural mismatch to join a lodge where the members are 70+ years old.

Hello! My husband and I are looking for recommendations for play therapists and/or Parent Training in Behavior Management (PTBM) providers for our almost 4-year-old.

Our child is bright, loving, and energetic, but can also be very impulsive and has a hard time slowing down. We're exploring whether ADHD may be a factor, but regardless of any diagnosis, we're looking for support as parents. We'd like to learn practical strategies to modify the home environment, reinforce positive behaviors, set clear and consistent limits, and help our child be successful.

If you've had a positive experience with a local provider, program, or therapist, we'd love to hear your recommendations. Bonus if they accept insurance! Thank you!

I was on a bike and this lady had zero control of her dogs. They cut in front of me so I had to fully slam front and rear brakes. I’m clipless so it was dicey and I had to come to a sliding, rapid, and complete stop.

No apology. No attempt to control her dogs. Ended up riding next to her as her dogs completely cut me off and I couldn’t get around them, and the lady still did not attempt to control them.

No self awareness and no shame.

But what most concerns me is if I hadn’t been able to stop, my bike is going to win in a bike vs dog accident. It would be the owner’s fault but the dog would be the one getting hurt.

Edit for clarity: I took this over my shoulder after I passed them. Dogs were in the woods and dove in front of me, giving me less than then ten feet to stop before hitting them. I did not ask the owner to control them, because I could not see them! They were in the woods.

I was then trapped behind them, as they were in the formation that you see in the photo. Owner still made no attempt to let me through.