December weather in Flagstaff, AZ
The average temperature in Flagstaff in December is 30.0°F (16.9°F–43.0°F). Average precipitation: 1.90 inches. Average snowfall is 18.5 inches.
December is a winter month in Flagstaff, and is cooler than the annual average of 46.8°F. Daily temperatures swing about 26.1°F between overnight low and afternoon high. Expect about 7 days with precipitation. Daylight averages about 9h 38m. For travel, December is cold.
Avg High
43.0°F
Avg Low
16.9°F
Precipitation
1.90 in
Snow
18.5 in
December records in Flagstaff
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| December 1 | 66.0°F (2008) | -2.0°F (1991) | 1.38 in (2007) |
| December 2 | 62.1°F (1893) | -5.1°F (1991) | 0.87 in (1906) |
| December 3 | 66.9°F (1977) | -2.0°F (1931) | 1.48 in (1906) |
| December 4 | 66.9°F (1965) | -4.0°F (1952) | 1.55 in (1992) |
| December 5 | 66.9°F (1989) | -0.9°F (1931) | 0.98 in (1966) |
| December 6 | 62.1°F (1977) | -6.0°F (1951) | 2.87 in (1966) |
| December 7 | 66.0°F (1958) | -18.9°F (1978) | 1.75 in (2009) |
| December 8 | 63.0°F (2015) | -23.1°F (1978) | 0.83 in (1972) |
| December 9 | 64.0°F (2025) | -8.9°F (2013) | 1.10 in (1965) |
| December 10 | 64.9°F (1939) | -9.8°F (2013) | 0.97 in (1961) |
| December 11 | 68.0°F (1950) | -11.0°F (1961) | 0.98 in (1927) |
| December 12 | 63.0°F (1950) | -16.1°F (1931) | 0.88 in (1937) |
| December 13 | 66.9°F (2010) | -18.9°F (1931) | 1.52 in (1967) |
| December 14 | 63.0°F (1977) | -14.1°F (1972) | 1.41 in (1967) |
| December 15 | 63.0°F (1929) | -14.1°F (1931) | 0.92 in (1961) |
| December 16 | 63.0°F (1958) | -18.0°F (1971) | 1.32 in (1924) |
| December 17 | 64.9°F (1939) | -14.1°F (1928) | 1.20 in (1978) |
| December 18 | 62.1°F (2025) | -11.0°F (1928) | 2.65 in (1978) |
| December 19 | 62.1°F (1958) | -14.1°F (1924) | 2.32 in (1967) |
| December 20 | 62.1°F (2018) | -11.9°F (1924) | 1.16 in (1968) |
| December 21 | 62.1°F (2024) | -9.9°F (1897) | 0.80 in (1959) |
| December 22 | 62.1°F (2025) | -16.1°F (1968) | 1.50 in (1965) |
| December 23 | 62.1°F (1933) | -23.1°F (1990) | 1.05 in (1982) |
| December 24 | 61.0°F (1933) | -17.0°F (1974) | 1.67 in (2021) |
| December 25 | 66.9°F (1980) | -14.1°F (1926) | 1.31 in (1940) |
| December 26 | 63.0°F (1980) | -16.1°F (1924) | 1.83 in (1971) |
| December 27 | 66.9°F (1980) | -14.1°F (1924) | 1.22 in (1984) |
| December 28 | 61.0°F (1980) | -11.9°F (1966) | 2.50 in (1992) |
| December 29 | 64.9°F (2017) | -13.0°F (1988) | 3.33 in (2004) |
| December 30 | 62.1°F (2017) | -9.9°F (1990) | 2.95 in (1951) |
| December 31 | 61.0°F (1980) | -13.0°F (2010) | 0.95 in (1936) |