Corvallis, OR 97333 Frost Dates
97333, near Corvallis, OR: the frost window
The last spring frost here typically falls around 04/11, about 226 days from today. Fall's first freeze usually shows up around 10/30, roughly 203 days after the last spring frost.
Zone 8b (15 to 20°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 Corvallis, not a forecast for this year.
Stretching the season past the first frost
Corvallis's growing season runs out in roughly 9 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 04/11 isn't a guarantee
04/11 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/11 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/05 and only about 1 year in 10 sees frost after that.
Corvallis against the rest of the dataset
Corvallis's growing season runs about 203 days, ranking 16,835 of 40,283 US ZIP codes measured here, longest to shortest. Within OR, it ranks 219 of 463.
Learn more
Two guides worth reading on 97333: zone vs. frost date, on why Zone 8b and Corvallis's frost date answer different questions, and the frost range, on how to read the range around Corvallis's dates instead of trusting one.