Frost dates for Portland Wfo, OR
At this NOAA station the last spring frost (32°F) usually comes by March 13 and the first fall frost around November 22, giving a growing season of about 251 days.
March 13average last spring frost
November 22average first fall frost
JanAprJulOctDec
Frost odds
| 1 year in 10 the last spring frost is later than | April 5 |
| Half of years the last spring frost is later than | March 13 |
| 9 years in 10 the last spring frost is later than | February 20 |
| 1 year in 10 the first fall frost is earlier than | November 3 |
| Half of years the first fall frost is earlier than | November 22 |
| 9 years in 10 the first fall frost is earlier than | December 14 |
A hard freeze (28°F) usually ends by February 12 and returns around December 10.
A light frost (36°F, which can still nip tender plants) usually ends by April 10 and returns around November 5.
Station USC00356750, elevation 6 m. Based on 23 years of 1991 to 2020 records. A garden higher up, in a hollow or far from this station can freeze later in spring.
Check another ZIP
Sources
- U.S. Annual/Seasonal Climate Normals, 1991 to 2020 (freeze probability dates by station), NOAA National Centers for Environmental Information, checked 1 November 2026
- Annual/Seasonal Normals 1991 to 2020 documentation, NOAA National Centers for Environmental Information, checked 1 November 2026
- 2024 Gazetteer Files, ZIP Code Tabulation Areas, US Census Bureau, checked 1 November 2026