December weather in Hermiston, OR
The average temperature in Hermiston in December is 35.2°F (28.2°F–42.1°F). Average precipitation: 1.12 inches.
December is a winter month in Hermiston, and is cooler than the annual average of 53.9°F. Daily temperatures swing about 13.9°F between overnight low and afternoon high. Expect about 11 days with precipitation. Daylight averages about 8h 29m. For travel, December is cold.
Avg High
42.1°F
Avg Low
28.2°F
Precipitation
1.12 in
Daylight
8h 29m
December records in Hermiston
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| December 1 | 71.1°F (2021) | 11.1°F (2014) | 0.23 in (2003) |
| December 2 | 60.1°F (2008) | 16.2°F (2009) | 0.30 in (2012) |
| December 3 | 70.0°F (2007) | 13.1°F (2013) | 0.25 in (2023) |
| December 4 | 64.9°F (2007) | 2.1°F (2013) | 0.28 in (2025) |
| December 5 | 60.1°F (2023) | 1.2°F (2013) | 0.14 in (2001) |
| December 6 | 57.9°F (2015) | 1.2°F (2013) | 0.55 in (2007) |
| December 7 | 57.0°F (2025) | -6.9°F (2013) | 0.39 in (2015) |
| December 8 | 72.0°F (2015) | -7.8°F (2013) | 0.21 in (2022) |
| December 9 | 66.0°F (2015) | -2.7°F (2013) | 0.59 in (2025) |
| December 10 | 70.0°F (2025) | -6.9°F (2009) | 0.26 in (2023) |
| December 11 | 69.1°F (2014) | -2.7°F (2009) | 0.29 in (2002) |
| December 12 | 64.0°F (2025) | 10.2°F (2013) | 0.19 in (2015) |
| December 13 | 62.1°F (1998) | 16.2°F (2009) | 0.41 in (2003) |
| December 14 | 68.0°F (2002) | 14.2°F (2008) | 0.49 in (2006) |
| December 15 | 75.0°F (2025) | -4.9°F (2008) | 0.22 in (2009) |
| December 16 | 64.9°F (2025) | -15.9°F (2008) | 0.17 in (2009) |
| December 17 | 66.0°F (2025) | -12.8°F (2016) | 0.19 in (2024) |
| December 18 | 61.0°F (2025) | 2.1°F (2008) | 0.32 in (2025) |
| December 19 | 57.9°F (2020) | 6.3°F (2008) | 1.05 in (2021) |
| December 20 | 66.0°F (2019) | -2.9°F (1998) | 0.25 in (2021) |
| December 21 | 64.9°F (2019) | -2.9°F (1998) | 0.21 in (2009) |
| December 22 | 54.0°F (2014) | -2.9°F (1998) | 0.26 in (2015) |
| December 23 | 61.0°F (2013) | -2.9°F (1998) | 0.25 in (2018) |
| December 24 | 50.0°F (2003) | 5.2°F (2017) | 0.56 in (2014) |
| December 25 | 50.0°F (1998) | 3.2°F (2008) | 0.43 in (2024) |
| December 26 | 57.9°F (2024) | 19.0°F (2004) | 0.38 in (2025) |
| December 27 | 61.0°F (2022) | 7.2°F (2021) | 0.33 in (2024) |
| December 28 | 61.0°F (2011) | 11.1°F (2021) | 0.51 in (2010) |
| December 29 | 60.1°F (1998) | 5.2°F (2021) | 0.58 in (2010) |
| December 30 | 55.9°F (1998) | 5.0°F (2003) | 0.70 in (2005) |
| December 31 | 55.9°F (2020) | -8.9°F (2021) | 0.63 in (2005) |