Roundup Weather in December
Average highs run from 40°F on December 1 to 36°F on December 31, and lows from 18°F to 12°F. Normal precipitation for the month is 0.41 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
- 37°F
- Average low
- 14°F
- Precipitation
- 0.41 in
- Snowfall
- 5.6 in
- Record high
- 78°FDec 5, 1939
- Record low
- -39°FDec 24, 1983
- Chance of a freeze
- 100%
- Daylight
- 8 h 52 min to 8 h 39 min
- Cloud cover
- 68%
- Humidity
- 74%
- Dew point
- 17°F
- Wind
- 11.6 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 | 40°F | 18°F | 70°F 1988 | -18°F 1985 | 12% | 8% |
| Dec 2 | 40°F | 17°F | 66°F 1959 | -27°F 1985 | 13% | 8% |
| Dec 3 | 40°F | 17°F | 67°F 1987 | -17°F 1972 | 13% | 9% |
| Dec 4 | 39°F | 17°F | 68°F 1988 | -23°F 1972 | 13% | 9% |
| Dec 5 | 39°F | 17°F | 78°F 1939 | -23°F 1956 | 13% | 9% |
| Dec 6 | 39°F | 16°F | 68°F 1939 | -31°F 1956 | 13% | 9% |
| Dec 7 | 39°F | 16°F | 63°F 1939 | -29°F 2013 | 13% | 9% |
| Dec 8 | 38°F | 16°F | 66°F 1940 | -36°F 1972 | 13% | 9% |
| Dec 9 | 38°F | 15°F | 67°F 1975 | -29°F 1977 | 13% | 9% |
| Dec 10 | 38°F | 15°F | 64°F 1939 | -16°F 1972 | 13% | 10% |
| Dec 11 | 38°F | 15°F | 68°F 1939 | -23°F 1961 | 13% | 10% |
| Dec 12 | 37°F | 15°F | 64°F 1962 | -19°F 1949 | 13% | 10% |
| Dec 13 | 37°F | 14°F | 63°F 1960 | -14°F 1972 | 13% | 10% |
| Dec 14 | 37°F | 14°F | 65°F 1997 | -20°F 1951 | 13% | 10% |
| Dec 15 | 37°F | 14°F | 69°F 1962 | -25°F 1945 | 14% | 10% |
| Dec 16 | 37°F | 14°F | 67°F 1980 | -31°F 1964 | 14% | 10% |
| Dec 17 | 37°F | 14°F | 67°F 1976 | -27°F 2016 | 14% | 11% |
| Dec 18 | 36°F | 13°F | 67°F 1979 | -29°F 1955 | 14% | 11% |
| Dec 19 | 36°F | 13°F | 66°F 2004 | -22°F 1990 | 14% | 11% |
| Dec 20 | 36°F | 13°F | 65°F 1941 | -27°F 1951 | 14% | 11% |
| Dec 21 | 36°F | 13°F | 65°F 1954 | -37°F 1989 | 14% | 11% |
| Dec 22 | 36°F | 13°F | 60°F 1940 | -37°F 1989 | 14% | 11% |
| Dec 23 | 36°F | 13°F | 61°F 1936 | -24°F 1983 | 14% | 11% |
| Dec 24 | 36°F | 13°F | 63°F 1999 | -39°F 1983 | 14% | 12% |
| Dec 25 | 36°F | 13°F | 60°F 1947 | -20°F 1983 | 14% | 12% |
| Dec 26 | 36°F | 12°F | 64°F 1980 | -30°F 1983 | 15% | 12% |
| Dec 27 | 36°F | 12°F | 67°F 1980 | -22°F 1965 | 15% | 12% |
| Dec 28 | 36°F | 12°F | 62°F 1956 | -31°F 1984 | 15% | 12% |
| Dec 29 | 36°F | 12°F | 68°F 1956 | -36°F 1968 | 15% | 12% |
| Dec 30 | 36°F | 12°F | 63°F 1980 | -32°F 1968 | 15% | 12% |
| Dec 31 | 36°F | 12°F | 59°F 1963 | -26°F 1992 | 15% | 12% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (MST).
- December 1
- sunrise 7:37 AM, sunset 4:29 PM
- December 31
- sunrise 7:58 AM, sunset 4:37 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00247214 (Roundup), public domain. Records: NOAA GHCN-Daily, station USC00243727, 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.