Portland, OR 97204 Frost Dates
Portland, OR: when does the frost end?
The last spring frost here typically falls around 03/13, about 197 days from today. Fall's first freeze usually shows up around 11/19, roughly 247 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Portland in Zone 9a (20 to 25°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
Stretching the season past the first frost
With roughly 12 weeks until Portland's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around Portland's last frost
03/13 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 02/22 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/01 and only about 1 year in 10 sees frost after that.
Portland against the rest of the dataset
At roughly 247 frost-free days, Portland places 7,756 of 40,283 ZIP codes in this dataset. Within OR, it ranks 84 of 463.
Learn more
Before leaning on 97204's figures: the frost range explains how to read the range around Portland's dates instead of trusting one, while local microclimates explains what one yard in Portland can differ from the 97204 normal.