Casper Weather in December
Average highs run from 41°F on December 1 to 37°F on December 31, and lows from 21°F to 16°F. Normal precipitation for the month is 0.65 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
- 38°F
- Average low
- 17°F
- Precipitation
- 0.65 in
- Snowfall
- 11.0 in
- Record high
- 66°FDec 2, 2021
- Record low
- -42°FDec 22, 2022
- Chance of a freeze
- 100%
- Daylight
- 9 h 15 min to 9 h 05 min
- Cloud cover
- 62%
- Humidity
- 70%
- Dew point
- 16°F
- Wind
- 14.8 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 | 41°F | 21°F | 63°F 1995 | -23°F 1985 | 15% | 21% |
| Dec 2 | 41°F | 20°F | 66°F 2021 | -15°F 1985 | 16% | 22% |
| Dec 3 | 40°F | 20°F | 58°F 1998 | -6°F 1955 | 16% | 22% |
| Dec 4 | 40°F | 20°F | 59°F 1965 | -22°F 2013 | 16% | 22% |
| Dec 5 | 40°F | 19°F | 57°F 1987 | -27°F 1972 | 16% | 22% |
| Dec 6 | 39°F | 19°F | 57°F 1981 | -24°F 1972 | 16% | 22% |
| Dec 7 | 39°F | 19°F | 56°F 1965 | -27°F 2016 | 16% | 22% |
| Dec 8 | 39°F | 19°F | 55°F 1965 | -33°F 2016 | 16% | 22% |
| Dec 9 | 38°F | 18°F | 57°F 1981 | -23°F 1977 | 16% | 22% |
| Dec 10 | 38°F | 18°F | 60°F 1990 | -18°F 1961 | 16% | 23% |
| Dec 11 | 38°F | 18°F | 60°F 2025 | -19°F 1985 | 16% | 23% |
| Dec 12 | 38°F | 18°F | 60°F 2014 | -14°F 2000 | 16% | 23% |
| Dec 13 | 38°F | 17°F | 57°F 2014 | -16°F 1967 | 16% | 23% |
| Dec 14 | 37°F | 17°F | 59°F 2025 | -19°F 2008 | 16% | 23% |
| Dec 15 | 37°F | 17°F | 59°F 2025 | -20°F 2008 | 16% | 23% |
| Dec 16 | 37°F | 17°F | 60°F 2025 | -31°F 1964 | 16% | 23% |
| Dec 17 | 37°F | 17°F | 60°F 1980 | -31°F 1964 | 16% | 23% |
| Dec 18 | 37°F | 16°F | 52°F 1994 | -18°F 1983 | 16% | 23% |
| Dec 19 | 37°F | 16°F | 59°F 2025 | -24°F 1990 | 16% | 23% |
| Dec 20 | 37°F | 16°F | 56°F 2024 | -36°F 1990 | 16% | 23% |
| Dec 21 | 37°F | 16°F | 57°F 2024 | -41°F 1990 | 16% | 23% |
| Dec 22 | 37°F | 16°F | 61°F 2025 | -42°F 2022 | 16% | 23% |
| Dec 23 | 37°F | 16°F | 63°F 2025 | -39°F 1983 | 16% | 23% |
| Dec 24 | 37°F | 16°F | 63°F 2025 | -33°F 1983 | 16% | 23% |
| Dec 25 | 37°F | 16°F | 61°F 2025 | -15°F 2009 | 16% | 23% |
| Dec 26 | 37°F | 16°F | 53°F 1980 | -17°F 2017 | 16% | 23% |
| Dec 27 | 37°F | 16°F | 61°F 1980 | -13°F 2017 | 16% | 22% |
| Dec 28 | 37°F | 16°F | 53°F 2005 | -26°F 1983 | 16% | 22% |
| Dec 29 | 37°F | 16°F | 51°F 1965 | -25°F 1990 | 16% | 22% |
| Dec 30 | 37°F | 16°F | 56°F 1980 | -29°F 1978 | 16% | 22% |
| Dec 31 | 37°F | 16°F | 54°F 1980 | -34°F 1978 | 16% | 22% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (MST).
- December 1
- sunrise 7:17 AM, sunset 4:32 PM
- December 31
- sunrise 7:36 AM, sunset 4:41 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00481569 (Casper Wwtp), public domain. Records: NOAA GHCN-Daily, station USW00024089, 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.