Average Temperatures for Washington in September
Average temperatures for September at cities and other locations throughout Washington are listed below in degrees Fahrenheit and Celsius.
You can jump to a separate table for each region of the state: Olympic Peninsula & West Coast, San Juan Islands & Puget Sound, Cascade Mountains and Eastern Washington.
The tables give the normals for maximum and minimum temperatures based on weather data collected from 1991 to 2020 by the US National Centers for Environmental Information.
Olympic Peninsula & West Coast
| High °F | Low °F | Place | High °C | Low °C |
|---|---|---|---|---|
| 69 | 51 | Aberdeen | 20 | 11 |
| 70 | 46 | Clearwater | 21 | 8 |
| 70 | 47 | Forks | 21 | 9 |
| 68 | 48 | Friday Harbor, San Juan Island | 20 | 9 |
| 77 | 42 | Grayland | 25 | 5 |
| 66 | 48 | Long Beach | 19 | 9 |
| 65 | 51 | Port Angeles | 18 | 11 |
San Juan Islands, Puget Sound & South
| High °F | Low °F | Place | High °C | Low °C |
|---|---|---|---|---|
| 70 | 51 | Anacortes | 21 | 11 |
| 68 | 50 | Bellingham | 20 | 10 |
| 72 | 51 | Bremerton | 22 | 11 |
| 73 | 48 | Centralia | 23 | 9 |
| 68 | 52 | Everett | 20 | 11 |
| 76 | 50 | Longview | 24 | 10 |
| 69 | 49 | Mount Vernon | 20 | 9 |
| 79 | 52 | Oak Harbor, Whidbey Island | 26 | 11 |
| 65 | 51 | Olga, Orcas Island | 18 | 11 |
| 72 | 46 | Olympia | 22 | 8 |
| 68 | 51 | Port Townsend | 20 | 11 |
| 72 | 54 | Seattle | 22 | 12 |
| 74 | 48 | Shelton | 23 | 9 |
| 71 | 53 | Tacoma | 22 | 12 |
| 74 | 47 | Vancouver | 23 | 8 |
Cascade Mountains
| High °F | Low °F | Place | High °C | Low °C |
|---|---|---|---|---|
| 69 | 47 | Baker Lake Dam | 20 | 9 |
| 71 | 48 | Baring | 22 | 9 |
| 72 | 47 | Darrington | 22 | 9 |
| 75 | 42 | Mt Adams Ranger Station | 24 | 6 |
| 57 | 41 | Mt Rainier Paradise Ranger Station | 14 | 5 |
| 70 | 48 | Mud Mountain Lake Dam | 21 | 9 |
| 70 | 50 | Ross Dam | 21 | 10 |
| 63 | 47 | Stampede Pass | 17 | 8 |
Eastern Washington State
| High °F | Low °F | Place | High °C | Low °C |
|---|---|---|---|---|
| 73 | 43 | Boundary Dam | 23 | 6 |
| 77 | 49 | Chelan | 25 | 10 |
| 77 | 51 | Coulee Dam | 25 | 10 |
| 81 | 53 | Kennewick | 27 | 12 |
| 78 | 42 | Leavenworth | 26 | 5 |
| 79 | 47 | Moses Lake | 26 | 8 |
| 76 | 44 | Pullman | 24 | 7 |
| 74 | 49 | Spokane | 23 | 9 |
| 79 | 54 | Walla Walla | 26 | 12 |
| 67 | 50 | Wenatchee | 19 | 10 |
| 77 | 41 | Winthrop | 25 | 5 |
| 79 | 45 | Yakima | 26 | 7 |
Reference
NOAA National Centers for Environmental Information (NCEI). Climate Normals.