Okanogan, WA 98829 Frost Dates
When can you plant in Okanogan, WA?
Typically, the last spring freeze lands around 04/30, roughly 245 days out. The first fall frost typically arrives around 10/07, about 160 frost-free days later.
Okanogan sits in USDA Zone 6b (-5 to 0°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 Okanogan before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 04/30 isn't a guarantee
04/30 is the middle of 30 years of NOAA records, not a promise. Plant by 04/14 and you're betting against frost in roughly 9 years out of 10. 05/15 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Okanogan compares
Okanogan's growing season runs about 160 days, ranking 32,373 of 40,283 US ZIP codes measured here, longest to shortest. Within WA, it ranks 570 of 700.
Learn more
zone vs. frost date covers why Zone 6b and Okanogan's frost date answer different questions. the frost range covers how to read the range around Okanogan's dates instead of trusting one.