Philomath, OR 97339 Frost Dates
When can you plant in Philomath, OR?
The last spring frost here typically falls around 05/15, about 260 days from today. The first fall frost typically arrives around 10/08, about 145 frost-free days later.
Philomath 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.
What to do before the first frost
About 6 weeks of growing season left in Philomath before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
The actual range around Philomath's last frost
05/15 is the middle of 30 years of NOAA records, not a promise. Plant by 04/28 and you're betting against frost in roughly 9 years out of 10. 06/02 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Philomath compares
Philomath's growing season runs about 145 days, ranking 36,184 of 40,283 US ZIP codes measured here, longest to shortest. Within OR, it ranks 362 of 463.
Learn more
zone vs. frost date covers why Zone 8b and Philomath's frost date answer different questions. the frost range covers how to read the range around Philomath's dates instead of trusting one.