Boulder Weather in December
Average highs run from 49°F on December 1 to 46°F on December 31, and lows from 23°F to 21°F. Normal precipitation for the month is 0.81 in over about 5 wet days.
December day by day
The normal high and low for each date, and the record, in °F.
- Normal low
- Normal high
- Record high
- Record low
December at a glance
- Average high
- 46°F
- Average low
- 21°F
- Precipitation
- 0.81 in
- Snowfall
- 13.0 in
- Record high
- 76°FDec 17, 1980
- Record low
- -24°FDec 22, 1990
- Chance of a freeze
- 100%
- Daylight
- 9 h 32 min to 9 h 23 min
- Cloud cover
- 63%
- Humidity
- 74%
- Dew point
- 12°F
- Wind
- 10.3 mph
Every day of the month
A wet day has at least 0.01 inch of precipitation; snow means at least 0.1 inch of snowfall.
| Date | Normal high | Normal low | Record high | Record low | Chance wet | Chance of snow |
|---|---|---|---|---|---|---|
| Dec 1 | 49°F | 23°F | 72°F 2021 | -5°F 1985 | 19% | 17% |
| Dec 2 | 48°F | 23°F | 72°F 2021 | -9°F 1919 | 19% | 17% |
| Dec 3 | 48°F | 23°F | 70°F 1926 | -2°F 1919 | 19% | 17% |
| Dec 4 | 48°F | 23°F | 75°F 1965 | -1°F 1909 | 18% | 17% |
| Dec 5 | 47°F | 22°F | 71°F 2012 | -12°F 1972 | 18% | 17% |
| Dec 6 | 47°F | 22°F | 69°F 1981 | -16°F 1972 | 18% | 17% |
| Dec 7 | 47°F | 22°F | 68°F 1984 | -15°F 1927 | 18% | 17% |
| Dec 8 | 47°F | 22°F | 71°F 1940 | -9°F 1932 | 18% | 17% |
| Dec 9 | 47°F | 21°F | 74°F 1957 | -20°F 1919 | 18% | 17% |
| Dec 10 | 46°F | 21°F | 70°F 1915 | -12°F 1932 | 18% | 17% |
| Dec 11 | 46°F | 21°F | 71°F 1934 | -18°F 1932 | 18% | 17% |
| Dec 12 | 46°F | 21°F | 68°F 2017 | -19°F 1932 | 18% | 17% |
| Dec 13 | 46°F | 21°F | 74°F 1921 | -10°F 1926 | 18% | 17% |
| Dec 14 | 46°F | 21°F | 69°F 1924 | -11°F 1901 | 18% | 17% |
| Dec 15 | 46°F | 21°F | 70°F 2006 | -15°F 2008 | 18% | 17% |
| Dec 16 | 46°F | 21°F | 69°F 1941 | -7°F 2008 | 18% | 17% |
| Dec 17 | 46°F | 21°F | 76°F 1980 | -9°F 1964 | 18% | 17% |
| Dec 18 | 46°F | 20°F | 69°F 1979 | -14°F 1909 | 18% | 17% |
| Dec 19 | 46°F | 20°F | 70°F 2025 | -17°F 1924 | 18% | 17% |
| Dec 20 | 46°F | 20°F | 70°F 1954 | -16°F 1924 | 18% | 17% |
| Dec 21 | 46°F | 20°F | 66°F 1982 | -20°F 1990 | 18% | 17% |
| Dec 22 | 46°F | 20°F | 72°F 2025 | -24°F 1990 | 18% | 17% |
| Dec 23 | 46°F | 20°F | 71°F 1955 | -14°F 2022 | 18% | 17% |
| Dec 24 | 46°F | 20°F | 71°F 2025 | -18°F 1924 | 18% | 17% |
| Dec 25 | 46°F | 21°F | 70°F 2025 | -10°F 1983 | 18% | 17% |
| Dec 26 | 46°F | 21°F | 70°F 1947 | -6°F 1916 | 18% | 17% |
| Dec 27 | 46°F | 21°F | 74°F 1980 | -10°F 1916 | 18% | 17% |
| Dec 28 | 46°F | 21°F | 67°F 1980 | -8°F 1924 | 18% | 17% |
| Dec 29 | 46°F | 21°F | 69°F 1965 | -13°F 1990 | 18% | 17% |
| Dec 30 | 46°F | 21°F | 71°F 1980 | -11°F 1990 | 18% | 17% |
| Dec 31 | 46°F | 21°F | 66°F 1904 | -18°F 1923 | 18% | 17% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (MST).
- December 1
- sunrise 7:04 AM, sunset 4:36 PM
- December 31
- sunrise 7:23 AM, sunset 4:46 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00050848 (Boulder), public domain. Records: NOAA GHCN-Daily, station USC00050848, every year on file, quality-flagged values removed. Cloud, humidity, wind and sunshine: NASA POWER (MERRA-2, CERES and GEWEX SRB), 1991-2020. The data was obtained from the National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project funded through the NASA Earth Science Division: POWER Daily API v2, accessed 2026-09-24. Sun and moon: computed with the NOAA solar equations and Meeus.