Lewistown Weather in December
Average highs run from 38°F on December 1 to 34°F on December 31, and lows from 17°F to 12°F. Normal precipitation for the month is 0.51 in over about 7 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
- 35°F
- Average low
- 14°F
- Precipitation
- 0.51 in
- Snowfall
- 16.1 in
- Record high
- 74°FDec 5, 1939
- Record low
- -42°FDec 24, 1983
- Chance of a freeze
- 100%
- Daylight
- 8 h 47 min to 8 h 34 min
- Cloud cover
- 70%
- Humidity
- 80%
- Dew point
- 16°F
- Wind
- 12.1 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 | 38°F | 17°F | 66°F 1988 | -27°F 1985 | 23% | 18% |
| Dec 2 | 38°F | 16°F | 62°F 1907 | -27°F 1919 | 23% | 18% |
| Dec 3 | 37°F | 16°F | 66°F 1907 | -22°F 1972 | 22% | 18% |
| Dec 4 | 37°F | 16°F | 71°F 1907 | -26°F 1928 | 22% | 18% |
| Dec 5 | 37°F | 16°F | 74°F 1939 | -23°F 1956 | 22% | 18% |
| Dec 6 | 36°F | 15°F | 64°F 1939 | -27°F 2013 | 22% | 18% |
| Dec 7 | 36°F | 15°F | 64°F 1939 | -32°F 1972 | 22% | 18% |
| Dec 8 | 36°F | 15°F | 66°F 1930 | -32°F 1972 | 22% | 18% |
| Dec 9 | 36°F | 15°F | 65°F 1915 | -36°F 1919 | 22% | 18% |
| Dec 10 | 35°F | 14°F | 64°F 1990 | -22°F 1961 | 22% | 18% |
| Dec 11 | 35°F | 14°F | 64°F 1939 | -28°F 1932 | 22% | 18% |
| Dec 12 | 35°F | 14°F | 60°F 1924 | -23°F 1922 | 23% | 18% |
| Dec 13 | 35°F | 14°F | 65°F 1960 | -22°F 1963 | 23% | 18% |
| Dec 14 | 35°F | 14°F | 60°F 1924 | -29°F 2008 | 23% | 18% |
| Dec 15 | 35°F | 13°F | 62°F 1962 | -29°F 1964 | 23% | 18% |
| Dec 16 | 35°F | 13°F | 61°F 1980 | -31°F 1964 | 23% | 18% |
| Dec 17 | 34°F | 13°F | 65°F 1925 | -30°F 1924 | 23% | 18% |
| Dec 18 | 34°F | 13°F | 62°F 1979 | -37°F 1924 | 23% | 18% |
| Dec 19 | 34°F | 13°F | 61°F 1954 | -27°F 1924 | 23% | 19% |
| Dec 20 | 34°F | 13°F | 60°F 1900 | -28°F 1990 | 24% | 19% |
| Dec 21 | 34°F | 13°F | 60°F 1900 | -35°F 1989 | 24% | 19% |
| Dec 22 | 34°F | 13°F | 58°F 1994 | -32°F 1990 | 24% | 19% |
| Dec 23 | 34°F | 12°F | 60°F 1994 | -37°F 1983 | 24% | 19% |
| Dec 24 | 34°F | 12°F | 55°F 1994 | -42°F 1983 | 24% | 19% |
| Dec 25 | 34°F | 12°F | 57°F 2025 | -30°F 1983 | 24% | 19% |
| Dec 26 | 34°F | 12°F | 56°F 1956 | -22°F 1904 | 24% | 20% |
| Dec 27 | 34°F | 12°F | 60°F 1980 | -32°F 1916 | 25% | 20% |
| Dec 28 | 34°F | 12°F | 58°F 1956 | -37°F 1968 | 25% | 20% |
| Dec 29 | 34°F | 12°F | 65°F 1956 | -41°F 1968 | 25% | 20% |
| Dec 30 | 34°F | 12°F | 58°F 1904 | -34°F 1978 | 25% | 21% |
| Dec 31 | 34°F | 12°F | 61°F 1926 | -40°F 1927 | 25% | 21% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (MST).
- December 1
- sunrise 7:43 AM, sunset 4:30 PM
- December 31
- sunrise 8:04 AM, sunset 4:38 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USW00024036 (Lewistown Muni AP), public domain. Records: NOAA GHCN-Daily, station USW00024036, 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 2026-09-25. Sun and moon: computed with the NOAA solar equations and Meeus.