December averages
- Average high
- 45.9°F
- Average low
- 17.7°F
- Snow
- 6.6 in
- Precipitation
- 0.47 in
Monthly averages: NOAA U.S. Climate Normals 1991-2020, Denver-Stapleton station. Averages, not forecasts.
- December in Denver averages highs near 46 degrees and lows near 18, with about 30 nights at or below freezing, according to federal climate normals.
- The city’s largest one-day snowfall on record, 23.6 inches, fell on December 24, 1982, the National Weather Service says.
- On I-70 between Morrison and Dotsero, Colorado’s traction law can be enforced from September 1 to May 31.
If you moved to Denver expecting endless blizzards, December can be a surprise. Many days are bright and dry, the snow on lawns melts in the sun, and the mountains to the west look like a postcard. Then a storm arrives and the city is buried for a day or two. Learning that rhythm is the first lesson of a Denver winter.
December by the numbers
Federal climate normals for Denver’s former Stapleton airport station, the long-running weather site in the city, describe a typical December:
| Measure | December normal |
|---|---|
| Average high | about 46°F |
| Average low | about 18°F |
| Nights at or below freezing | about 30 |
| Snowfall | about 6.6 inches |
| Precipitation (melted) | about 0.47 inch |
That last number explains the dry feel. Denver’s snow is usually light and fluffy, so several inches can hold less than half an inch of water. The air is dry too. Lips crack, static shocks are common, and a humidifier can make a bedroom more comfortable.
When it snows, it can snow a lot
The National Weather Service office for Denver and Boulder keeps the city’s records. The largest one-day snowfall since 1882 fell on December 24, 1982, when 23.6 inches came down. December also holds other spots in the top ten: 20.9 inches on December 4, 1913, and 20.7 inches on December 20, 2006. Holiday travel plans in Denver should always include a backup.
December can also be bitterly cold for short spells. The Weather Service lists a low of 25 below zero on December 22, 1990, among the coldest temperatures recorded in Denver.
Getting your car ready
Mountain trips are part of the reason people move here, and winter driving on I-70 has rules. The Colorado Department of Transportation says that between September 1 and May 31, or whenever conditions require, the traction law can be enforced on I-70 from Morrison to Dotsero.
- Under the passenger vehicle traction law, cars need tires with at least 3/16-inch tread that are rated for all-weather or snow use, among other options the state lists.
- During severe storms CDOT can impose the chain law, the last step before a road closes, when every vehicle needs chains or an approved alternative traction device.
- Not complying can bring a $100 fine plus a $33 surcharge; if your vehicle causes a lane closure, the penalty rises to $500 plus a $157 surcharge.
- Alerts appear on highway signs and COtrip.org, and CDOT offers text and email alerts.
Tip: Check your tire tread with a ruler before your first ski or holiday trip. Bald summer tires are the most common reason newcomers get stuck, or fined, on the way to the mountains.
Registering the car
If you arrived this fall, the clock may already be running on vehicle registration. Colorado gives new residents 90 days from the date residency is established to register a vehicle, and Adams County’s clerk explains that the state counts residency from the point you have lived in Colorado continuously for 90 days, among other triggers. Late registration costs $25 a month, up to $100. Registration is handled by the county clerk where you live.
The free winter gift: a library card
Short days are a good time to discover the Denver Public Library. Its card policy says a library card is free for any Colorado resident. To get a full-use card, bring a school or government-issued photo ID and proof of a current Colorado address to any location; you can start the application online. The library’s newcomer guide counts 26 locations across the city.
With a card you can borrow books, movies and music, and also Wi-Fi hotspots and museum and state parks passes. Without a card you can still attend programs such as storytimes, computer classes and the ideaLAB makerspaces. Denver Public Library does not charge overdue fines, though long-overdue items block borrowing until they are returned.
Around the house
- Know where your water shut-off is and keep garden hoses disconnected so outdoor spigots do not freeze.
- Have a snow shovel and ice melt ready before the first big storm, not after.
- Keep a blanket, water and a scraper in the car for mountain trips.
- Watch the forecast for sudden temperature drops; Denver’s weather records include same-day swings of dozens of degrees.
Make the most of it
December’s sunny days are excellent for walks in the city’s parks and for short hikes in the foothills, with layers and traction devices for icy trails. Plan bigger mountain days around storms, not into them. And when a real snowstorm does arrive, enjoy it: by the next sunny afternoon, much of it may already be melting. Next month’s guide, Denver in January: The Coldest Month, the Stock Show and New-Resident Paperwork, covers the coldest stretch of the year.