Warrenton, OR 97121 Frost Dates
97121, near Warrenton, OR: the frost window
The last spring frost here typically falls around 03/26, about 210 days from today. Fall's first freeze usually shows up around 11/11, roughly 232 days after the last spring frost.
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 Warrenton, not a forecast for this year.
Stretching the season past the first frost
Warrenton's growing season runs out in roughly 11 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 03/26 isn't a guarantee
03/26 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 02/27 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/18 and only about 1 year in 10 sees frost after that.
Warrenton against the rest of the dataset
At roughly 232 frost-free days, Warrenton places 10,039 of 40,283 ZIP codes in this dataset. Within OR, it ranks 138 of 463.
Learn more
Two guides worth reading on 97121: local microclimates, on what one yard in Warrenton can differ from the 97121 normal, and zone vs. frost date, on why Zone 9a and Warrenton's frost date answer different questions.