Weather history and climate summary information is available for the following locations:
- Bellingham
- Grant County Airport
- Seattle
- Spokane
- Tacoma
- Walla Walla
- Yakima
Warmest October Days
The warmest October days in Washington are:
| Walla Walla, Washington | 1997 | 91.4°F |
| Grant County Airport, Washington | 1988 | 90°F |
| Walla Walla, Washington | 1942 | 89.2°F |
| Grant County Airport, Washington | 1987 | 89.1°F |
| Grant County Airport, Washington | 1980 | 89.1°F |
Coldest October Days
The coldest October days in Washington were:
| Yakima, Washington | 2002 | 3.9°F |
| Spokane, Washington | 2002 | 7°F |
| Grant County Airport, Washington | 2006 | 10.9°F |
| Spokane, Washington | 1984 | 10.9°F |
| Yakima, Washington | 2006 | 10.9°F |
Wettest October Days
The wettest single days in October occurred:
| Seattle, Washington | 2003 | 4.6 inches |
| Spokane, Washington | 2010 | 4.4 inches |
| Tacoma, Washington | 1986 | 2.6 inches |
| Bellingham, Washington | 1979 | 2.5 inches |
| Bellingham, Washington | 2003 | 2.4 inches |