Frost dates in Union, OR

The average last spring frost in Union is around May 24 and the first fall frost is around September 19. That gives Union an average growing season of about 118 days.

Last spring frost

Early (10% chance after)May 6
Average (50%)May 24
Late (90%)June 12

First fall frost

Early (10%)September 3
Average (50%)September 19
Late (90% chance before)October 6

See the Union planting calendar →