Keizer, OR 97305 Frost Dates
97305, near Keizer, OR: the frost window
Typically, the last spring freeze lands around 04/03, roughly 218 days out. Fall's first freeze usually shows up around 11/01, roughly 212 days after the last spring frost.
Keizer sits in USDA Zone 8b (15 to 20°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
Stretching the season past the first frost
Keizer'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.
How much risk comes with planting early here
04/03 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/10 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/27 and only about 1 year in 10 sees frost after that.
Keizer against the rest of the dataset
Keizer's growing season runs about 212 days, ranking 14,567 of 40,283 US ZIP codes measured here, longest to shortest. Within OR, it ranks 200 of 463.
Learn more
Two guides worth reading on 97305: zone vs. frost date, on why Zone 8b and Keizer's frost date answer different questions, and the frost range, on how to read the range around Keizer's dates instead of trusting one.