Seattle, WA 98119 Frost Dates
When can you plant in Seattle, WA?
Around 03/08 is the usual last spring frost, about 192 days away. The first fall frost typically arrives around 11/23, about 259 frost-free days later.
Seattle sits in USDA Zone 9a (20 to 25°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 12 weeks of growing season left in Seattle before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
How much risk comes with planting early here
03/08 is the middle of 30 years of NOAA records, not a promise. Plant by 02/13 and you're betting against frost in roughly 9 years out of 10. 03/29 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Seattle compares
At roughly 259 frost-free days, Seattle places 6,511 of 40,283 ZIP codes in this dataset. Within WA, it ranks 27 of 700.
Learn more
local microclimates covers what one yard in Seattle can differ from the 98119 normal. zone vs. frost date covers why Zone 9a and Seattle's frost date answer different questions.