December weather in Sidney, MT
The average temperature in Sidney in December is 20.6°F (10.7°F–30.6°F). Average precipitation: 0.51 inches. Average snowfall is 7.9 inches.
December is a winter month in Sidney, and is cooler than the annual average of 45.2°F. Daily temperatures swing about 19.9°F between overnight low and afternoon high. Expect about 6 days with precipitation. Daylight averages about 8h 13m. For travel, December is cold.
Avg High
30.6°F
Avg Low
10.7°F
Precipitation
0.51 in
Snow
7.9 in
December records in Sidney
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| December 1 | 64.9°F (2021) | -13.0°F (1919) | 0.13 in (1972) |
| December 2 | 59.0°F (1988) | -27.0°F (1985) | 0.47 in (1982) |
| December 3 | 55.0°F (1989) | -24.0°F (1972) | 0.20 in (2010) |
| December 4 | 68.0°F (1979) | -26.0°F (1972) | 0.25 in (1910) |
| December 5 | 54.0°F (1963) | -29.9°F (1994) | 0.40 in (2001) |
| December 6 | 63.0°F (2023) | -27.0°F (1972) | 0.24 in (1916) |
| December 7 | 57.0°F (2023) | -26.0°F (1972) | 0.25 in (1977) |
| December 8 | 60.1°F (2020) | -29.9°F (1972) | 0.29 in (2008) |
| December 9 | 62.1°F (1912) | -36.9°F (1977) | 0.12 in (1953) |
| December 10 | 55.0°F (1987) | -25.1°F (1919) | 0.17 in (2010) |
| December 11 | 62.1°F (2004) | -18.0°F (2013) | 0.22 in (1995) |
| December 12 | 57.0°F (2017) | -27.0°F (1916) | 0.42 in (1968) |
| December 13 | 53.1°F (1999) | -22.0°F (1985) | 0.10 in (1982) |
| December 14 | 59.0°F (1912) | -29.9°F (1963) | 0.48 in (2022) |
| December 15 | 59.0°F (1998) | -31.0°F (1963) | 0.10 in (1921) |
| December 16 | 57.9°F (1962) | -29.9°F (1951) | 0.42 in (2022) |
| December 17 | 64.9°F (1912) | -25.1°F (1975) | 0.10 in (1970) |
| December 18 | 62.1°F (1979) | -27.0°F (1955) | 0.15 in (2002) |
| December 19 | 52.0°F (2020) | -31.0°F (1989) | 0.13 in (1949) |
| December 20 | 55.0°F (2004) | -29.0°F (1916) | 0.40 in (2010) |
| December 21 | 55.0°F (2023) | -32.1°F (1989) | 0.14 in (2009) |
| December 22 | 55.9°F (1954) | -34.1°F (1989) | 0.33 in (1964) |
| December 23 | 46.0°F (2025) | -40.0°F (1983) | 0.26 in (1973) |
| December 24 | 48.9°F (1999) | -32.1°F (1980) | 0.13 in (1972) |
| December 25 | 52.0°F (1963) | -35.0°F (1996) | 0.29 in (2009) |
| December 26 | 51.1°F (2025) | -27.0°F (1990) | 0.36 in (2018) |
| December 27 | 63.0°F (1912) | -24.0°F (2017) | 1.15 in (2016) |
| December 28 | 55.0°F (1980) | -26.0°F (1968) | 0.36 in (1978) |
| December 29 | 55.0°F (2011) | -32.1°F (1916) | 0.17 in (1915) |
| December 30 | 51.1°F (1912) | -34.1°F (1968) | 0.50 in (1921) |
| December 31 | 59.0°F (1912) | -34.1°F (1967) | 0.62 in (1975) |