Frost dates in Portland, OR

The average last spring frost in Portland is around March 3 and the first fall frost is around November 28. That gives Portland an average growing season of about 270 days.

Last spring frost

Early (10% chance after)January 22
Average (50%)March 3
Late (90%)March 22

First fall frost

Early (10%)November 2
Average (50%)November 28
Late (90% chance before)December 18

See the Portland planting calendar →