Sumas, WA 98295 Frost Dates
Frost dates for Sumas, WA, ZIP 98295
The last spring frost here typically falls around 03/31, about 215 days from today. The first fall frost typically arrives around 10/30, about 211 frost-free days later.
The USDA Plant Hardiness Zone Map puts Sumas in Zone 8a (10 to 15°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
What to do before the first frost
Zone 8a around Sumas has about 9 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
03/31 is the middle of 30 years of NOAA records, not a promise. Plant by 03/10 and you're betting against frost in roughly 9 years out of 10. 04/18 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Sumas compares
At roughly 211 frost-free days, Sumas places 14,794 of 40,283 ZIP codes in this dataset. Within WA, it ranks 269 of 700.
Learn more
the frost range explains how to read the range around Sumas's dates instead of trusting one, and local microclimates explains what one yard in Sumas can differ from the 98295 normal.