Boulder Weather in December
Average highs run from 36°F on December 1 to 34°F on December 31, and lows from 14°F to 11°F. Normal precipitation for the month is 0.27 in over about 6 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
- 34°F
- Average low
- 12°F
- Precipitation
- 0.27 in
- Record high
- 66°FDec 27, 1917
- Record low
- -52°FDec 23, 1983
- Chance of a freeze
- 100%
- Daylight
- 8 h 53 min to 8 h 41 min
- Cloud cover
- 68%
- Humidity
- 85%
- Dew point
- 15°F
- Wind
- 7.8 mph
Every day of the month
A wet day has at least 0.01 inch of precipitation.
| Date | Normal high | Normal low | Record high | Record low | Chance wet |
|---|---|---|---|---|---|
| Dec 1 | 36°F | 14°F | 61°F 2021 | -16°F 1985 | 20% |
| Dec 2 | 36°F | 14°F | 57°F 2021 | -15°F 1931 | 20% |
| Dec 3 | 35°F | 14°F | 55°F 1956 | -21°F 1992 | 20% |
| Dec 4 | 35°F | 14°F | 56°F 1965 | -37°F 1972 | 20% |
| Dec 5 | 35°F | 13°F | 54°F 2023 | -40°F 1972 | 20% |
| Dec 6 | 35°F | 13°F | 54°F 1900 | -28°F 1972 | 20% |
| Dec 7 | 34°F | 13°F | 54°F 2024 | -31°F 1978 | 20% |
| Dec 8 | 34°F | 13°F | 58°F 2020 | -39°F 1972 | 20% |
| Dec 9 | 34°F | 12°F | 57°F 1957 | -40°F 1972 | 20% |
| Dec 10 | 34°F | 12°F | 57°F 1990 | -34°F 1961 | 20% |
| Dec 11 | 34°F | 12°F | 51°F 2004 | -36°F 1932 | 20% |
| Dec 12 | 33°F | 12°F | 60°F 1924 | -28°F 1919 | 20% |
| Dec 13 | 33°F | 11°F | 60°F 1924 | -25°F 1919 | 20% |
| Dec 14 | 33°F | 11°F | 59°F 2025 | -26°F 1967 | 20% |
| Dec 15 | 33°F | 11°F | 55°F 2025 | -27°F 1967 | 20% |
| Dec 16 | 33°F | 11°F | 58°F 1980 | -36°F 1964 | 20% |
| Dec 17 | 33°F | 11°F | 53°F 1980 | -38°F 1964 | 20% |
| Dec 18 | 33°F | 11°F | 55°F 1979 | -32°F 1924 | 20% |
| Dec 19 | 33°F | 11°F | 52°F 2004 | -27°F 1945 | 20% |
| Dec 20 | 33°F | 11°F | 49°F 1940 | -36°F 1998 | 20% |
| Dec 21 | 33°F | 11°F | 51°F 2020 | -43°F 1983 | 20% |
| Dec 22 | 33°F | 10°F | 53°F 1933 | -44°F 1990 | 20% |
| Dec 23 | 33°F | 10°F | 50°F 1950 | -52°F 1983 | 20% |
| Dec 24 | 33°F | 10°F | 50°F 1899 | -40°F 1983 | 20% |
| Dec 25 | 33°F | 10°F | 49°F 1899 | -30°F 1944 | 20% |
| Dec 26 | 33°F | 10°F | 53°F 1980 | -23°F 1996 | 20% |
| Dec 27 | 33°F | 10°F | 66°F 1917 | -25°F 1941 | 20% |
| Dec 28 | 33°F | 10°F | 56°F 1917 | -35°F 1983 | 20% |
| Dec 29 | 33°F | 10°F | 55°F 1917 | -42°F 1978 | 20% |
| Dec 30 | 33°F | 11°F | 55°F 1917 | -42°F 1978 | 20% |
| Dec 31 | 34°F | 11°F | 53°F 1917 | -39°F 1978 | 20% |
Chance of rain
- Chance of a wet day
Sunrise and sunset
Times for 2026, local time (MST).
- December 1
- sunrise 7:51 AM, sunset 4:44 PM
- December 31
- sunrise 8:11 AM, sunset 4:52 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00241008 (Boulder), public domain. Records: NOAA GHCN-Daily, station USW00024135, 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.