Weather history and climate summary information is available for the following locations:
- Eugene
- Medford
- Pendleton
- Portland
Warmest December Days
The warmest December days in Oregon are:
| Medford, Oregon | 1979 | 68°F |
| Eugene, Oregon | 1979 | 68°F |
| Medford, Oregon | 1993 | 68°F |
| Pendleton, Oregon | 1975 | 66.9°F |
| Pendleton, Oregon | 1980 | 66.9°F |
Coldest December Days
The coldest December days in Oregon were:
| Pendleton, Oregon | 1983 | -18.9°F |
| Pendleton, Oregon | 1990 | -16.1°F |
| Pendleton, Oregon | 2008 | -9.9°F |
| Pendleton, Oregon | 1984 | -7.1°F |
| Pendleton, Oregon | 1978 | -6.2°F |
Wettest December Days
The wettest single days in December occurred:
| Eugene, Oregon | 1981 | 4.7 inches |
| Eugene, Oregon | 1980 | 3.9 inches |
| Eugene, Oregon | 1975 | 3 inches |
| Eugene, Oregon | 1987 | 2.9 inches |
| Eugene, Oregon | 1998 | 2.9 inches |