Boulder, CO weather in December
In December, Boulder sees highs around 46°F and lows around 21°F: chilly and snowy. Expect about 5 wet days. Snowfall averages about 13.0 in. It is one of the coldest months in Boulder. Pack for snow.
- Normal high
- 46°F
- Normal low
- 21°F
- Wet days
- 5
- 0.8 in total
- Snowfall
- 13.0 in
- snow on the ground 13 days
How December changes from start to finish
| December 1 | December 31 | |
|---|---|---|
| Normal high | 49°F | 46°F |
| Normal low | 23°F | 21°F |
| Chance of a wet day | 18% | 18% |
| Sunrise / sunset | 7:03 am / 4:36 pm | 7:22 am / 4:45 pm |
| Daylight | 9.5 h | 9.4 h |
Chance of a wet day: average for the first and last 7 days of the month. Times are local clock time (Mountain Time).
A typical December day
- 6 am25°Fdew point 13°F
- 9 am31°Fdew point 15°F
- Noon40°Fdew point 16°F
- 3 pm41°Fdew point 16°F
- 6 pm31°Fdew point 16°F
- 9 pm28°Fdew point 15°F
NOAA hourly normals (local standard time) from Denver Intl Airport (35 mi away); average wind 10 mph; clear or few clouds in 37% of daytime hours, mostly cloudy or overcast in 46%.
What kind of days to expect
- Comfortable dayshigh 65-80°F and dew point under 60°F1 of 31
- Hot dayshigh 90°F or more0 of 31
- Muggy daysdaily mean dew point 65°F or more0 of 31
- Wet daysat least 0.01 in of rain or melted snow5 of 31
- Notable rainat least 0.10 in3 of 31
- Freezing nightslow 32°F or below27 of 31
- Snow on the groundsnow depth 1 in or more13 of 31
Average days per December, counted from daily records for each year 1991-2020.
Rain and snow in December
Normal precipitation is 0.8 in; a dry December brings about 0.4 in and a wet one about 1.0 in (25th and 75th percentiles). Days with half an inch or more are rare. Normal snowfall is 13.0 in, with about 3 days of an inch or more.
How December varies from year to year
- Warmest December, 1991-20202017: average high 51°F
- Coolest December2009: average high 38°F
- Wettest December2006: 3.0 in
- Driest December1991: 0.01 in
- Highest reading71°F (December 5, 2012)
- Lowest reading-15°F (December 15, 2008)
From the station's daily records with NOAA quality flags removed; most recent date shown when a reading repeats.
December compared with November and January
| November | December | January | |
|---|---|---|---|
| Normal high | 55°F | 46°F | 47°F |
| Normal low | 28°F | 21°F | 22°F |
| Wet days | 6 | 5 | 6 |
| Comfortable days | 8 | 1 | 1 |
| Daylight | 10.0 h | 9.4 h | 9.7 h |
Highs change by -9°F from November and +1°F into January.
Nearby alternatives in December
- Cooler: Estes Park, CO28 mi · high 40°F · 7 wet days
How Boulder ranks in December
- Normal high216th warmest of 378 cities; 3rd of 17 in Colorado
- Wet days56th driest of 378
- Comfortable days198th most of 340
What to pack for Boulder in December
- A warm jacket – lows near 21°F, highs near 46°F
- Layers – afternoons near 46°F but nights near 21°F
- Waterproof boots – snow on the ground on about 13 days
- A hat and gloves – about 27 freezing nights
Heating and cooling
December has 970 heating degree days and 0 cooling degree days (base 65°F), 16% of the year's total heating and cooling demand.
Questions
How cold is Boulder in December?
The normal high is 46°F and the normal low is 21°F. From 1991 to 2020 the coldest December reading was -15°F (December 15, 2008).
Does it rain a lot in Boulder in December?
About 5 days in December have at least 0.01 in of precipitation, and the normal total is 0.8 in. The wettest December in 1991-2020 was in 2006 (3.1 in); the driest was in 1991 (0.01 in).
Does it snow in Boulder in December?
Yes. Normal snowfall in December is 13.0 in, and snow covers the ground on about 13 days.
Is December a good time to visit Boulder?
December ranks 12th of 12 months on our comfort score for Boulder (40 out of 100). It has about 1 comfortable day. The best month is May.
Where the numbers come from
- Temperature, rain, snowfall, snow depth and frost dates: Boulder (USC00050848), 1.6 mi S of the city center, 5,484 ft (165 ft higher than the city). NOAA normals and daily records, 1991-2020.
- Humidity and wind by hour: Denver Intl Airport (USW00003017), 35 mi ESE of the city center, 5,414 ft (95 ft higher than the city). NOAA normals and daily records, 1991-2020.
- Cloud cover: Aurora Buckley Fld ANGB (USW00023036), 35 mi SE of the city center, 5,663 ft (344 ft higher than the city). NOAA normals and daily records, 1991-2020.
- Daily humidity and wind: Denver International Airport (725650-03017), 35 mi ESE of the city center, 5,404 ft (85 ft higher than the city). Hourly observations, 1991-2020.