Mount Vernon, WA 98274 Frost Dates
When can you plant in Mount Vernon, WA?
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.
Mount Vernon 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 10 weeks of growing season left in Mount Vernon before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 03/27 isn't a guarantee
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 Mount Vernon compares
Mount Vernon's growing season runs about 224 days, ranking 11,746 of 40,283 US ZIP codes measured here, longest to shortest. Within WA, it ranks 211 of 700.
Learn more
the frost range covers how to read the range around Mount Vernon's dates instead of trusting one. local microclimates covers what one yard in Mount Vernon can differ from the 98274 normal.