Oregon frost dates

Across Oregon, the average last spring frost is around April 20 and the average first fall frost around October 18 — roughly 181 frost-free days. USDA zones 4b, 5b, 6b, 7b, 8b, 9a, 9b.

Risk you accept	Last spring frost by	First fall frost by
Cautious (~10%)	May 4	October 4
Average (~50%)	April 20	October 18
Gambler (~90%)	April 6	November 1

Oregon spans a wide range of elevations and climates — your town’s dates can differ from the state average by two weeks or more. Look up your exact ZIP.

→ Turn these into sowing dates with the Oregon planting calendar, or look up an exact ZIP code.

Statewide average from NOAA/NCEI freeze normals. Cautious/gambler dates are about two weeks either side of the average.