Portland, OR Frost Dates
The last spring frost in Portland usually comes around March 13 and the first fall frost around November 19.
| Spring (last) | Fall (first) | |
|---|---|---|
| Frost, 32°F | March 13 | November 19 |
| Hard freeze, 28°F | February 16 | December 5 |
Growing season: about 247 days.
Frequently asked questions
When is the last frost in Portland, OR?
The median date of the last spring frost (32°F) is March 13. In half of years the last frost comes earlier and in half it comes later, so waiting a week or two past March 13 lowers the risk for tender plants.
When is the first frost in Portland?
The median date of the first fall frost (32°F) is November 19, and a hard freeze (28°F) usually follows around December 5.
How long is the growing season in Portland?
About 247 days between the median last spring frost and first fall frost.
NOAA NCEI U.S. Climate Normals 1991-2020, station USW00024229. Median (50% probability) dates. Low spots and valleys can frost later in spring and earlier in fall than the station.