December weather in Sinclair, WY
The average temperature in Sinclair in December is 22.1°F (12.8°F–31.3°F). Average precipitation: 0.40 inches.
December is a winter month in Sinclair, and is cooler than the annual average of 43.1°F. Daily temperatures swing about 18.5°F between overnight low and afternoon high. Expect about 6 days with precipitation. Daylight averages about 8h 59m. For travel, December is cold.
Avg High
31.3°F
Avg Low
12.8°F
Precipitation
0.40 in
Daylight
8h 59m
December records in Sinclair
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| December 1 | 55.9°F (1995) | -4.0°F (1954) | 0.37 in (2007) |
| December 2 | 60.1°F (2021) | -11.0°F (1978) | 0.26 in (1982) |
| December 3 | 55.0°F (1998) | -11.9°F (2009) | 0.41 in (2013) |
| December 4 | 53.1°F (2021) | -23.8°F (2013) | 0.28 in (1954) |
| December 5 | 48.9°F (1965) | -27.9°F (1972) | 0.27 in (1978) |
| December 6 | 53.1°F (2023) | -22.0°F (1972) | 0.49 in (1956) |
| December 7 | 50.0°F (1965) | -26.0°F (2005) | 0.17 in (1974) |
| December 8 | 48.9°F (1965) | -18.0°F (1956) | 0.22 in (1985) |
| December 9 | 54.0°F (1981) | -24.0°F (1972) | 0.49 in (2021) |
| December 10 | 55.0°F (1990) | -27.0°F (1972) | 0.15 in (1985) |
| December 11 | 52.0°F (1995) | -18.9°F (1963) | 0.17 in (1958) |
| December 12 | 50.0°F (2025) | -14.1°F (1972) | 0.59 in (1958) |
| December 13 | 50.0°F (1998) | -13.0°F (1967) | 0.41 in (2022) |
| December 14 | 55.9°F (2025) | -9.9°F (2007) | 0.21 in (1990) |
| December 15 | 52.0°F (1952) | -13.0°F (1965) | 0.08 in (1954) |
| December 16 | 54.0°F (1962) | -25.1°F (1965) | 0.27 in (1996) |
| December 17 | 57.0°F (1962) | -27.9°F (1964) | 0.25 in (1967) |
| December 18 | 52.0°F (2023) | -20.0°F (1989) | 0.23 in (2008) |
| December 19 | 54.0°F (2025) | -16.1°F (1990) | 0.24 in (2010) |
| December 20 | 48.9°F (2023) | -35.0°F (1990) | 0.72 in (2010) |
| December 21 | 55.0°F (2024) | -35.0°F (1990) | 0.42 in (2010) |
| December 22 | 55.9°F (2025) | -32.1°F (1990) | 0.12 in (1972) |
| December 23 | 55.9°F (2025) | -22.9°F (2022) | 0.57 in (1987) |
| December 24 | 55.9°F (2025) | -18.0°F (1983) | 0.35 in (1971) |
| December 25 | 53.1°F (2025) | -27.0°F (1987) | 0.36 in (2016) |
| December 26 | 48.9°F (1980) | -24.0°F (1987) | 0.31 in (1969) |
| December 27 | 55.9°F (1980) | -20.7°F (2015) | 0.30 in (1975) |
| December 28 | 48.9°F (1980) | -20.7°F (2015) | 0.18 in (1972) |
| December 29 | 48.0°F (2024) | -20.0°F (1978) | 0.39 in (1972) |
| December 30 | 52.0°F (1980) | -18.0°F (1978) | 0.10 in (1957) |
| December 31 | 52.0°F (1980) | -27.0°F (1978) | 0.34 in (1995) |