Rocky Mountain National Park (Rocky Mountains) weather in December

December in Rocky Mountain National Park: freezing, a little rain, with clean air — not the time — well below freezing.

Updated September 2026 · climate normals from ERA5 reanalysis

Rocky Mountain National Park🇺🇸 United States · Rockies · National park47
  1. 45Jan
  2. 49Feb
  3. 62Mar
  4. 69Apr
  5. 77May
  6. 92Jun
  7. 88Jul
  8. 94Aug
  9. 90Sep
  10. 75Oct
  11. 60Nov
  12. 47Dec

#11 of 12 months in Rocky Mountain National Park · #1235 of 1413 destinations to visit in December · comfort 47/100 (tier F)

Days
-2°C
Nights
-9°C
Wet days
13
Sun
7.4 h
Humidity
68%
Daylight
9 h
Rocky Mountain National Park, United States
Photo: Jacob Moore · Pexels

Traveller notes on Rocky Mountain National Park in December

Notes from nearby Vail (98 km away)

Rocky Mountain National Park doesn't have its own notes for December yet — these are about Vail, close enough to share the season.

Vail-forum threads on December skiing describe early-season conditions as genuinely erratic, posters calling some years thin with little beyond machine-made snow while others open with a strong natural base already down. Regulars call the resort's extensive snowmaking a real advantage this time of year, keeping trails skiable through a dry stretch. Posters describe Vail's position west of the pass as catching more snow than resorts further into Summit County, a real edge during a lean early season. Regulars recommend checking current conditions directly rather than assuming last year's December repeats. Posters call the holiday stretch around Christmas reliably well-covered historically, most of the mountain typically open by then. Regulars recommend proper cold-weather layers for early runs, mornings genuinely sharp this time of year. The record: -0.8C days feeling like -5C, -12.7C nights, 58.1mm across nearly 12 days and 72 percent humidity.
VailDecemberRegular · December · 1 month ago · about Vail · Read more on Tripadvisor ↗

Other months in Rocky Mountain National Park

Rocky Mountain-forum threads on a January visit describe Moraine Park campground as genuinely open year-round, posters naming it first-come-first-served through the winter months. Regulars call trail conditions genuinely worth confirming directly with rangers, several posters warning the park website's own trail-condition page isn't reliably updated for winter snow and ice coverage. Posters call Bear Lake Road genuinely open through winter, several regulars naming a bad storm as the real exception that would close it temporarily. Regulars call mid-January genuinely a good time for organized events, several threads naming Winter Trails Day and the Estes Park Winter Festival as both falling around then. Posters recommend real traction devices and checking with rangers directly before a January hike, several regulars calling this standard given how unreliable online trail updates can be. The record: -2.9C days, -10.4C nights, 78.4mm across nearly 14 days and 70 percent humidity.
RockyMountainJanuaryRegular · January · 1 month ago · Read more on Tripadvisor ↗
Rocky Mountain National Park-forum threads on a March visit call this genuinely still winter at elevation, posters describing March as traditionally the snowiest month of the year on the park's east side. Regulars call snowshoeing the realistic way to hike this month, real trail conditions here varying considerably by elevation and recent weather. Regulars recommend Estes Park for snowshoe rentals, several posters describing this as the practical staging point for a March visit. Posters call Trail Ridge Road and Old Fall River Road both closed for winter, other park roads generally open weather permitting. Regulars call conditions at lower elevation genuinely inconsistent, snow coming and going in Estes Park without sticking for long. Posters recommend real cold-weather layers regardless of a sunny-looking morning, mountain weather here shifting fast. The record: 2C days feeling like 0C, -7.2C nights, an extraordinarily high 92.2mm across over 13 days and 66 percent humidity.
RockyMountainMarchRegular · March · 1 month ago · Read more on Tripadvisor ↗
Rocky Mountain-forum threads on an early November visit describe Trail Ridge Road and Old Fall River Road as both closed for the season, posters calling Moraine Park the only campground still running this late. Regulars recommend a warm coat, hat, gloves and waterproof boots regardless of how the day starts, real layers necessary given how fast conditions shift at elevation. Posters describe the higher trails as already carrying some accumulation, traction devices like microspikes rentable in Estes Park though not yet enough for snowshoes. Regulars call the lower valley trails still genuinely accessible and rewarding this time of year, considerably quieter than the summer crowds. Posters recommend checking current trail and road status before committing to a route. Regulars call the park a genuinely different, starker kind of beautiful once the leaves and crowds are gone. The record: 2.2C days feeling like -3C, -5.7C nights, 63mm across nearly 11 days and 65 percent humidity.
RockyMountainNPNovemberRegular · November · 1 month ago · Read more on Tripadvisor ↗
Rocky Mountain-forum threads on October conditions are consistent this month can genuinely deliver anything, warm and sunny one day and a real system the next, nothing guaranteed. Posters call nights below the freezing mark standard by this point, even while daytime readings down in Estes Park stay comfortably warm early in the month before cooling steadily. Regulars describe a roughly forty-degree Fahrenheit swing between morning lows and afternoon highs as typical, elevation adding several more degrees per thousand feet gained. Posters recommend real layers including hats and gloves for anyone heading up Trail Ridge Road, which can see closures at higher sections given how quickly conditions shift. Posters recommend checking current road status before a high-elevation route. The record: 8.8C days feeling like 5C, -0.7C nights, an extraordinarily high 58mm across 9 days, a notably high 19cm of fresh accumulation and 60 percent humidity.
RockyMountainOctoberRegular · October · 1 month ago · Read more on Tripadvisor ↗

Add your own note from Rocky Mountain National Park's card on the map.

Rocky Mountain National Park climate normals — December

Daytime high-2°C / 29°F🥶 freezing
Nighttime low-9°C / 15°F
Feels like (high)-7°C / 19°F
Rainfall75 mm / 3 in🌦 some rain
Rainy days13 days
Humidity68%💧 humid
Dew point-13°C / 9°F
Sunshine7.4 h/day
Daylight9.4 h
Wind16 km/h / 10 mph
Snowfall47.8 cm / 18.8 in
Air quality (US AQI)44🍃 good

Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.

Crowds in Rocky Mountain National Park in December

How busy the place itself is — school and mass holidays, the months an editor tagged, and how sought-after the weather makes them. Never part of the comfort score.

BusyWinter / Christmas break in United States, school holidays in 2 of the markets that fill it(estimated)

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Peak crowdsBusyShoulder seasonQuiet

Best months for Rocky Mountain National Park's weather

Ranked by this destination's own climate comfort score across the year — a different thing from how busy it gets (see Crowds above).

Toughest weatherRocky Mountain National Park's best weather comes in June, August and September — separate windows, not one continuous season.

December coincides with Avalanche season.

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Best weatherFair weatherToughest weather

What's on in Rocky Mountain National Park in December

Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.

  • Hazard

    Avalanche season

    15 Oct – 15 Jun · usually

    From mid-autumn into early summer steep snow slopes above popular trails such as Emerald Lake can slide. Check the Colorado avalanche forecast, and in spring cross snowfields in the morning before they soften. Source ↗

  • Season

    Ranger-led snowshoe walks

    15 Dec – 15 Mar · usuallySki season

    In snowy winters rangers lead two-hour snowshoe walks on weekends on both sides of the park into mid-March. Reservations open a week ahead and you bring or rent your own snowshoes in town. Source ↗

  • Season

    Snow season

    Ski season

    About 48 cm of snow falls in the month.

    from the climate normals

What's on around the world in December →

Nearby, and something's on

Within 300 km of Rocky Mountain National Park — a day trip or a short hop — with something on this month. Never part of the comfort score.

Where is Rocky Mountain National Park?

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Rocky Mountain National Park in December — FAQ

Is December a good time to visit Rocky Mountain National Park?
December in Rocky Mountain National Park: freezing, a little rain, with clean air — not the time — well below freezing. It ranks #11 of 12 months for Rocky Mountain National Park on SeasonMap's comfort score (47/100).
What is the weather like in Rocky Mountain National Park in December?
In December, Rocky Mountain National Park averages a daily high of -1.8°C and a low of -9.3°C, with about 75.1 mm of rain over roughly 12.7 rainy days.
What is the air quality in Rocky Mountain National Park in December?
Rocky Mountain National Park has a mean US Air Quality Index of about 44 in December.
Does it snow in Rocky Mountain National Park in December?
Rocky Mountain National Park sees roughly 47.8 cm of snowfall in December.

Within 300 km: Denver's Mountain ski season around 25 Oct – 20 Apr, and Vail's Ski season around 13 Nov – 18 Apr.