Chewelah, WA 99131 Frost Dates
Frost dates for Chewelah, WA, ZIP 99131
The last spring frost here typically falls around 05/16, about 261 days from today. The first fall frost typically arrives around 09/15, about 120 frost-free days later.
Zone 6b (-5 to 0°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 Chewelah, not a forecast for this year.
What to do before the first frost
Zone 6b around Chewelah has about 3 weeks left before the first fall frost — that's the usual window to get a cold frame up if you want to keep harvesting past it.
Why 05/16 isn't a guarantee
05/16 is the middle of 30 years of NOAA records, not a promise. Plant by 04/30 and you're betting against frost in roughly 9 years out of 10. 06/07 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Chewelah compares
At roughly 120 frost-free days, Chewelah places 39,079 of 40,283 ZIP codes in this dataset. Within WA, it ranks 657 of 700.
Learn more
zone vs. frost date explains why Zone 6b and Chewelah's frost date answer different questions, and the frost range explains how to read the range around Chewelah's dates instead of trusting one.