Frost dates in SeaTac, WA

The average last spring frost in SeaTac is around March 15 and the first fall frost is around November 12. That gives SeaTac an average growing season of about 242 days.

Last spring frost

Early (10% chance after)February 19
Average (50%)March 15
Late (90%)April 14

First fall frost

Early (10%)October 29
Average (50%)November 12
Late (90% chance before)December 5

See the SeaTac planting calendar →