December weather in Southwest City, MO
The average temperature in Southwest City in December is 41.5°F (31.9°F–51.1°F). Average precipitation: 3.17 inches. Average snowfall is 1.7 inches.
December is a winter month in Southwest City, and is cooler than the annual average of 60.5°F. Daily temperatures swing about 19.2°F between overnight low and afternoon high. Expect about 8 days with precipitation. Daylight averages about 9h 31m. For travel, December is cool.
Avg High
51.1°F
Avg Low
31.9°F
Precipitation
3.17 in
Snow
1.7 in
December records in Southwest City
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| December 1 | 73.9°F (1982) | 10.9°F (1985) | 1.47 in (2018) |
| December 2 | 77.0°F (2021) | 6.1°F (1985) | 1.24 in (1982) |
| December 3 | 77.0°F (2021) | 9.0°F (1929) | 1.42 in (1982) |
| December 4 | 73.0°F (1906) | 8.1°F (1905) | 2.36 in (1973) |
| December 5 | 75.9°F (1998) | 0.0°F (1898) | 1.43 in (1975) |
| December 6 | 72.0°F (1966) | -2.0°F (1950) | 2.09 in (1935) |
| December 7 | 75.9°F (1939) | -6.0°F (1950) | 1.04 in (1926) |
| December 8 | 77.0°F (1991) | -11.0°F (1917) | 1.68 in (1980) |
| December 9 | 73.0°F (2020) | -20.9°F (1917) | 3.02 in (1946) |
| December 10 | 75.9°F (2020) | -9.0°F (1917) | 2.49 in (2007) |
| December 11 | 73.0°F (1929) | 1.9°F (1917) | 1.47 in (1965) |
| December 12 | 73.0°F (1949) | -4.0°F (1962) | 1.05 in (1972) |
| December 13 | 75.9°F (1948) | 1.9°F (1917) | 3.63 in (1984) |
| December 14 | 73.0°F (1948) | -5.1°F (1985) | 2.91 in (1992) |
| December 15 | 77.0°F (1948) | -4.0°F (1901) | 2.08 in (1992) |
| December 16 | 75.0°F (1924) | -6.0°F (1989) | 2.12 in (2001) |
| December 17 | 69.1°F (1908) | 1.0°F (1979) | 2.31 in (2021) |
| December 18 | 72.0°F (1939) | -2.9°F (1901) | 3.15 in (1924) |
| December 19 | 73.0°F (1978) | -6.0°F (1945) | 2.03 in (1987) |
| December 20 | 70.0°F (1941) | -4.0°F (1901) | 2.52 in (1991) |
| December 21 | 69.1°F (2017) | -2.9°F (1989) | 2.12 in (1984) |
| December 22 | 70.0°F (1982) | -13.0°F (1989) | 1.16 in (1981) |
| December 23 | 72.0°F (2025) | -16.1°F (1989) | 3.10 in (1932) |
| December 24 | 77.0°F (1955) | -8.0°F (1983) | 2.40 in (1932) |
| December 25 | 77.0°F (2025) | -11.0°F (1983) | 2.35 in (1987) |
| December 26 | 80.1°F (2025) | -2.9°F (1983) | 1.00 in (1949) |
| December 27 | 81.0°F (2025) | 5.0°F (1904) | 6.90 in (2015) |
| December 28 | 75.0°F (2025) | -2.9°F (1925) | 1.58 in (2015) |
| December 29 | 70.0°F (1923) | -7.1°F (1983) | 2.01 in (1990) |
| December 30 | 70.0°F (1996) | -8.0°F (1983) | 1.67 in (2006) |
| December 31 | 77.0°F (1951) | -4.0°F (1976) | 2.48 in (1984) |