Washington climate almanac
Washington's climate, read through its 70 NOAA stations, is mainly marine / mediterranean (pacific coast, coastal california), then mild humid continental (northeast, midwest, pacific northwest), then desert southwest (arizona, nevada, inland california). The mean frost-free season runs from about April 26 to October 17, roughly 177 days.
Stations 70 NOAA 1991-2020 normals
Mean frost-free season 177 days 94 to 254 across the state
Typical frost window April 26 - October 17 Median last and first frost
Main climate types 3 Marine / Mediterranean (Pacific coast, coastal California) (31); Mild humid continental (Northeast, Midwest, Pacific Northwest) (25); Desert Southwest (Arizona, Nevada, inland California) (14)
What this means for your home
In Washington, the difference between the shortest and longest frost-free pockets is 160 days. That is the difference between a tomato crop that struggles and one that runs into October, between one fertilizer timing and another. Set your place above to tune every date to your nearest station.
Major cities in Washington
Pick a city to see its frost and planting dates, or set your own place above.