December weather in Alton, MO
The average temperature in Alton in December is 35.8°F (25.7°F–45.9°F). Average precipitation: 3.29 inches. Average snowfall is 0.8 inches.
December is a winter month in Alton, and is cooler than the annual average of 55.7°F. Daily temperatures swing about 20.2°F between overnight low and afternoon high. Expect about 7 days with precipitation. Daylight averages about 9h 30m. For travel, December is cool.
Avg High
45.9°F
Avg Low
25.7°F
Precipitation
3.29 in
Snow
0.8 in
December records in Alton
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| December 1 | 72.0°F (1982) | 10.9°F (1975) | 1.47 in (2006) |
| December 2 | 70.0°F (1973) | 12.0°F (1976) | 0.64 in (1967) |
| December 3 | 70.0°F (1998) | 12.0°F (2000) | 8.35 in (1982) |
| December 4 | 72.0°F (1998) | 9.0°F (2006) | 3.78 in (1982) |
| December 5 | 75.9°F (2001) | 9.0°F (2006) | 2.49 in (2011) |
| December 6 | 73.9°F (1998) | 3.9°F (2002) | 2.40 in (1975) |
| December 7 | 70.0°F (1966) | 3.9°F (2002) | 1.34 in (1971) |
| December 8 | 68.0°F (1970) | 3.0°F (2006) | 0.94 in (2022) |
| December 9 | 70.0°F (1970) | 3.0°F (2006) | 1.60 in (1961) |
| December 10 | 66.0°F (1971) | 0.0°F (1995) | 3.00 in (1971) |
| December 11 | 68.0°F (1996) | 1.0°F (1995) | 2.15 in (1960) |
| December 12 | 71.1°F (1996) | -2.9°F (1962) | 1.37 in (1965) |
| December 13 | 69.1°F (1969) | 0.0°F (1962) | 0.91 in (2000) |
| December 14 | 66.9°F (2006) | 7.0°F (1962) | 2.06 in (1967) |
| December 15 | 69.1°F (1995) | 8.1°F (1963) | 2.28 in (1948) |
| December 16 | 68.0°F (2006) | 10.0°F (1968) | 1.52 in (2001) |
| December 17 | 69.1°F (1962) | 3.9°F (2000) | 2.06 in (2001) |
| December 18 | 71.1°F (2006) | 1.9°F (1964) | 2.92 in (2021) |
| December 19 | 71.1°F (1978) | 3.0°F (1963) | 0.73 in (1995) |
| December 20 | 69.1°F (1978) | 1.9°F (1996) | 1.67 in (1973) |
| December 21 | 66.9°F (2013) | 1.9°F (1973) | 0.85 in (1962) |
| December 22 | 68.0°F (1982) | 1.9°F (2008) | 1.29 in (1968) |
| December 23 | 66.0°F (1982) | 1.9°F (2008) | 1.36 in (2017) |
| December 24 | 72.0°F (2025) | -4.0°F (2004) | 2.85 in (1982) |
| December 25 | 75.9°F (2025) | -4.0°F (2004) | 1.90 in (1982) |
| December 26 | 73.9°F (2025) | 6.1°F (2004) | 0.80 in (1975) |
| December 27 | 75.9°F (2025) | 8.1°F (2010) | 1.50 in (2011) |
| December 28 | 68.0°F (2008) | 12.9°F (1967) | 1.98 in (1968) |
| December 29 | 75.0°F (2025) | 9.0°F (1995) | 1.85 in (2003) |
| December 30 | 68.0°F (1965) | 8.1°F (1995) | 1.62 in (1972) |
| December 31 | 68.0°F (1999) | -6.0°F (1976) | 2.83 in (2002) |