Portland, OR 97232 Frost Dates
Frost dates for Portland, OR, ZIP 97232
The last spring frost here typically falls around 03/13, about 197 days from today. The first fall frost typically arrives around 11/19, about 247 frost-free days later.
Zone 9a (20 to 25°F average annual minimum) comes from the USDA Plant Hardiness Zone Map; the frost dates above are the 1991-2020 normal at the nearest reporting NOAA station for Portland, not a forecast for this year.
What to do before the first frost
Zone 9a around Portland has about 12 weeks left before the first fall frost — that's the usual window to get a cold frame up if you want to keep harvesting past it.
The actual range around Portland's last frost
03/13 is the middle of 30 years of NOAA records, not a promise. Plant by 02/22 and you're betting against frost in roughly 9 years out of 10. 04/01 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Portland compares
Portland's growing season runs about 247 days, ranking 7,764 of 40,283 US ZIP codes measured here, longest to shortest. Within OR, it ranks 92 of 463.
Learn more
zone vs. frost date explains why Zone 9a and Portland's frost date answer different questions, and the frost range explains how to read the range around Portland's dates instead of trusting one.