Philomath, OR 97370 Frost Dates
97370, near Philomath, OR: the frost window
Around 05/15 is the usual last spring frost, about 260 days away. Fall's first freeze usually shows up around 10/08, roughly 145 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 Philomath, not a forecast for this year.
Stretching the season past the first frost
Philomath's growing season runs out in roughly 6 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
05/15 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/28 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 06/02 and only about 1 year in 10 sees frost after that.
Philomath against the rest of the dataset
Philomath's growing season runs about 145 days, ranking 36,185 of 40,283 US ZIP codes measured here, longest to shortest. Within OR, it ranks 363 of 463.
Learn more
Two guides worth reading on 97370: the frost range, on how to read the range around Philomath's dates instead of trusting one, and local microclimates, on what one yard in Philomath can differ from the 97370 normal.