December weather in Roundup, MT
The average temperature in Roundup in December is 25.7°F (14.2°F–37.2°F). Average precipitation: 0.41 inches. Average snowfall is 5.6 inches.
December is a winter month in Roundup, and is cooler than the annual average of 46.5°F. Daily temperatures swing about 23°F between overnight low and afternoon high. Expect about 5 days with precipitation. Daylight averages about 8h 24m. For travel, December is cold.
Avg High
37.2°F
Avg Low
14.2°F
Precipitation
0.41 in
Snow
5.6 in
December records in Roundup
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| December 1 | 69.1°F (1969) | -23.1°F (1985) | 2.00 in (2000) |
| December 2 | 64.0°F (1959) | -43.1°F (1919) | 2.00 in (2000) |
| December 3 | 69.1°F (1943) | -31.0°F (1919) | 0.22 in (2010) |
| December 4 | 68.0°F (1943) | -17.0°F (1972) | 0.46 in (1978) |
| December 5 | 66.9°F (1939) | -33.0°F (1972) | 0.20 in (1920) |
| December 6 | 64.0°F (1939) | -35.0°F (1972) | 0.24 in (1977) |
| December 7 | 61.0°F (1984) | -24.0°F (2013) | 0.35 in (1994) |
| December 8 | 62.1°F (1934) | -35.0°F (1919) | 0.40 in (1983) |
| December 9 | 66.0°F (1957) | -36.9°F (1919) | 0.25 in (1917) |
| December 10 | 63.0°F (2015) | -27.0°F (1919) | 3.00 in (2000) |
| December 11 | 64.9°F (2004) | -31.0°F (1932) | 1.44 in (1919) |
| December 12 | 60.1°F (1934) | -27.9°F (1922) | 0.30 in (1983) |
| December 13 | 64.9°F (2017) | -27.0°F (1922) | 0.54 in (1937) |
| December 14 | 64.0°F (1952) | -20.9°F (1919) | 0.10 in (1917) |
| December 15 | 66.9°F (1980) | -25.1°F (2008) | 0.80 in (1989) |
| December 16 | 66.0°F (1942) | -27.0°F (1979) | 0.27 in (2016) |
| December 17 | 61.0°F (1976) | -32.1°F (2016) | 0.17 in (1955) |
| December 18 | 64.0°F (1954) | -34.1°F (1983) | 0.52 in (1973) |
| December 19 | 62.1°F (1954) | -17.0°F (1983) | 0.34 in (1934) |
| December 20 | 63.0°F (1954) | -22.0°F (1951) | 0.37 in (1939) |
| December 21 | 63.0°F (1954) | -26.0°F (2008) | 0.26 in (1966) |
| December 22 | 60.1°F (1933) | -36.0°F (1989) | 0.20 in (2000) |
| December 23 | 60.1°F (1922) | -26.0°F (1920) | 0.85 in (1955) |
| December 24 | 60.1°F (1922) | -44.0°F (1983) | 0.25 in (1964) |
| December 25 | 60.1°F (1947) | -33.0°F (1983) | 0.31 in (2018) |
| December 26 | 61.0°F (1976) | -29.9°F (1996) | 0.44 in (2003) |
| December 27 | 70.0°F (1980) | -34.1°F (1916) | 0.23 in (1996) |
| December 28 | 63.0°F (1980) | -34.1°F (1916) | 0.32 in (1978) |
| December 29 | 63.0°F (1956) | -27.9°F (1968) | 0.30 in (1941) |
| December 30 | 59.0°F (1956) | -35.0°F (1978) | 0.38 in (2017) |
| December 31 | 57.9°F (1963) | -27.0°F (1978) | 0.40 in (1944) |