December weather in Mattawa, WA
The average temperature in Mattawa in December is 35.4°F (29.9°F–40.9°F). Average precipitation: 1.40 inches.
December is a winter month in Mattawa, and is cooler than the annual average of 56°F. Daily temperatures swing about 11°F between overnight low and afternoon high. Expect about 10 days with precipitation. Daylight averages about 8h 22m. For travel, December is cold.
Avg High
40.9°F
Avg Low
29.9°F
Precipitation
1.40 in
Daylight
8h 22m
December records in Mattawa
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| December 1 | 66.0°F (1972) | 8.1°F (1985) | 0.29 in (1966) |
| December 2 | 63.0°F (1975) | 12.0°F (1985) | 1.50 in (2015) |
| December 3 | 64.0°F (1982) | 1.9°F (1985) | 0.51 in (1980) |
| December 4 | 61.0°F (1975) | 8.1°F (1972) | 0.43 in (1974) |
| December 5 | 60.1°F (2025) | 9.0°F (1972) | 0.52 in (2023) |
| December 6 | 61.0°F (1987) | 9.0°F (1956) | 0.50 in (2023) |
| December 7 | 59.0°F (1970) | 7.0°F (1956) | 0.30 in (1996) |
| December 8 | 68.0°F (2015) | 3.0°F (1972) | 0.56 in (1963) |
| December 9 | 66.0°F (2015) | 1.9°F (1972) | 1.50 in (1987) |
| December 10 | 70.0°F (2025) | 1.0°F (1972) | 0.50 in (2022) |
| December 11 | 66.9°F (2025) | 1.9°F (1972) | 0.92 in (1958) |
| December 12 | 61.0°F (2010) | -0.9°F (1972) | 0.71 in (1995) |
| December 13 | 60.1°F (1988) | 3.0°F (1972) | 1.05 in (1977) |
| December 14 | 59.0°F (1977) | 3.9°F (1972) | 1.00 in (2016) |
| December 15 | 63.0°F (1999) | 12.9°F (1964) | 0.33 in (1981) |
| December 16 | 64.9°F (1959) | -5.1°F (1964) | 0.38 in (1994) |
| December 17 | 66.0°F (1956) | -0.9°F (1964) | 0.40 in (2024) |
| December 18 | 57.0°F (2025) | 1.9°F (1984) | 0.28 in (1960) |
| December 19 | 57.9°F (1966) | -0.9°F (1984) | 0.25 in (1981) |
| December 20 | 64.9°F (1994) | 1.0°F (1984) | 0.71 in (1970) |
| December 21 | 63.0°F (2020) | 1.0°F (1984) | 0.96 in (1964) |
| December 22 | 59.0°F (1972) | -0.9°F (1983) | 0.34 in (2023) |
| December 23 | 62.1°F (1984) | -2.9°F (1983) | 0.62 in (1975) |
| December 24 | 57.9°F (1961) | 3.9°F (1990) | 0.42 in (1968) |
| December 25 | 60.1°F (1972) | 3.9°F (1990) | 0.62 in (2024) |
| December 26 | 71.1°F (1980) | 9.0°F (1983) | 0.76 in (2024) |
| December 27 | 64.9°F (1980) | 12.0°F (1990) | 0.64 in (1965) |
| December 28 | 62.1°F (1998) | 0.0°F (1968) | 0.30 in (2005) |
| December 29 | 64.9°F (1998) | -5.1°F (1968) | 0.50 in (2010) |
| December 30 | 60.1°F (2018) | -7.1°F (1968) | 0.67 in (2005) |
| December 31 | 60.1°F (2019) | -2.0°F (1968) | 0.74 in (1996) |