FrostDateCheck

Sedro-Woolley, WA 98220 Frost Dates

Frost dates for Sedro-Woolley, WA, ZIP 98220

Zone 8a

The last spring frost here typically falls around 03/27, about 211 days from today. The first fall frost typically arrives around 11/06, about 224 frost-free days later.

Sedro-Woolley sits in USDA Zone 8a (10 to 15°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

Zone 8a around Sedro-Woolley has about 10 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.

How much risk comes with planting early here

03/27 is the middle of 30 years of NOAA records, not a promise. Plant by 03/08 and you're betting against frost in roughly 9 years out of 10. 04/17 is the safer bet, historically only a 1-in-10 chance of frost that late.

How Sedro-Woolley compares

At roughly 224 frost-free days, Sedro-Woolley places 11,783 of 40,283 ZIP codes in this dataset. Within WA, it ranks 212 of 700.

Learn more

the frost range explains how to read the range around Sedro-Woolley's dates instead of trusting one, and local microclimates explains what one yard in Sedro-Woolley can differ from the 98220 normal.