This looks like a handy planting calendar. (from https://www.ufseeds.com/learning/planting-schedules/washington-vegetable-planting-calendar/)
Washington Last & First Frost Dates
| City | Last Frost Date | First Frost Date |
| Bellevue | 4/6 | 10/26 |
| Everett | 2/25 | 11/27 |
| Federal Way | 4/4 | 11/5 |
| Kent | 3/10 | 11/16 |
| Renton | 4/6 | 10/26 |
| Seattle | 4/20 | 10/17 |
| Spokane | 5/13 | 10/5 |
| Tacoma | 4/21 | 10/19 |
| Vancouver | 4/24 | 10/13 |
| Yakima | 5/10 | 9/26 |