December weather in Boulder, MT
The average temperature in Boulder in December is 22.5°F (11.5°F–33.6°F). Average precipitation: 0.27 inches.
December is a winter month in Boulder, and is cooler than the annual average of 42.6°F. Daily temperatures swing about 22.1°F between overnight low and afternoon high. Expect about 6 days with precipitation. Daylight averages about 8h 26m. For travel, December is cold.
Avg High
33.6°F
Avg Low
11.5°F
Precipitation
0.27 in
Daylight
8h 26m
December records in Boulder
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| December 1 | 64.9°F (2021) | -18.9°F (1985) | 0.31 in (1978) |
| December 2 | 64.9°F (2021) | -23.1°F (1985) | 0.27 in (1977) |
| December 3 | 57.0°F (1956) | -15.0°F (1972) | 0.62 in (1948) |
| December 4 | 60.1°F (1979) | -20.0°F (1972) | 0.09 in (1950) |
| December 5 | 55.9°F (2023) | -27.9°F (1972) | 0.10 in (1977) |
| December 6 | 57.0°F (2008) | -29.0°F (1972) | 0.30 in (1950) |
| December 7 | 57.0°F (2008) | -26.0°F (1956) | 0.12 in (1991) |
| December 8 | 57.0°F (2008) | -34.1°F (1972) | 0.10 in (1961) |
| December 9 | 60.1°F (1957) | -34.1°F (1972) | 0.18 in (1970) |
| December 10 | 57.0°F (2004) | -35.0°F (1972) | 0.12 in (1987) |
| December 11 | 57.0°F (2004) | -27.0°F (1961) | 0.17 in (1956) |
| December 12 | 55.9°F (2014) | -18.9°F (2000) | 0.37 in (1958) |
| December 13 | 54.0°F (2014) | -9.9°F (1963) | 0.15 in (1991) |
| December 14 | 60.1°F (2025) | -20.0°F (1967) | 0.33 in (2015) |
| December 15 | 61.0°F (2025) | -24.0°F (1967) | 0.32 in (2016) |
| December 16 | 62.1°F (1980) | -29.9°F (1964) | 0.27 in (1963) |
| December 17 | 59.0°F (1980) | -36.9°F (1964) | 0.21 in (1963) |
| December 18 | 54.0°F (1979) | -29.0°F (1983) | 0.21 in (1990) |
| December 19 | 54.0°F (2004) | -27.0°F (1990) | 0.10 in (1948) |
| December 20 | 50.0°F (1953) | -29.9°F (1990) | 0.20 in (1953) |
| December 21 | 52.0°F (2020) | -31.0°F (1983) | 0.28 in (1964) |
| December 22 | 51.1°F (1954) | -42.0°F (1990) | 0.17 in (1964) |
| December 23 | 53.1°F (1955) | -38.9°F (1983) | 0.45 in (1955) |
| December 24 | 53.1°F (2025) | -40.0°F (1983) | 0.19 in (1977) |
| December 25 | 48.9°F (1950) | -26.0°F (1983) | 0.49 in (1996) |
| December 26 | 57.9°F (1980) | -22.0°F (1951) | 0.56 in (1971) |
| December 27 | 60.1°F (1980) | -18.9°F (1988) | 0.15 in (1973) |
| December 28 | 53.1°F (1956) | -29.9°F (1983) | 0.19 in (1978) |
| December 29 | 51.1°F (1956) | -35.0°F (1990) | 0.15 in (1967) |
| December 30 | 52.0°F (2011) | -35.0°F (1978) | 0.37 in (2017) |
| December 31 | 53.1°F (1963) | -29.9°F (1978) | 0.15 in (1959) |