The Home Almanac

Vol. I, MMXXVIThe American home, in season.Across all fifty states

Planting dates for Seattle

Frost dates and sow windows from the 30-year record at Seattle Boeing Fld, the official station 7 km from Seattle, Washington.

Last spring frostMarch 13
First fall frostNovember 17
Frost-free season247 days

Sow and transplant events for the staples, straight from this page.

Key windows for Seattle (2026)

CropStart indoorsPlant out / sow
Tomato January 30 March 20
Pepper January 16 March 27
Peas February 6
Lettuce January 16 February 13
Carrot February 20
Bush beans March 20
Garlic Fall planted
Potato February 27

Mean-date planning windows, not guarantees; watch the local forecast at the shoulders. Method on the methodology page.

Seattle planting questions

When is the last frost in Seattle?

Around March 13, the 30-year mean date of the last spring frost at Seattle Boeing Fld, the official station 7 km from Seattle. Half of years see frost after the mean, so tender crops usually wait a week or more past it.

When can I plant tomatoes in Seattle?

Start seeds indoors around January 30 and transplant around March 20, once nights hold above 50F. The full 32-crop table on the planner computes every window for Seattle.

How long is the growing season in Seattle?

About 247 frost-free days on average, from roughly March 13 to November 17. Crops whose days-to-maturity exceed that window need transplants, short-season varieties, or season extension.

How this page was made

Every date above is computed from the NOAA NCEI U.S. Climate Normals at Seattle Boeing Fld: the 30-year mean dates of last spring and first fall frost, with crop offsets from standard horticultural practice. Full method and crop sources: data and methodology. These are planning averages, not forecasts: half of years frost later than the mean, so harden off transplants and watch the local forecast at the shoulders of the season.

More for Seattle: winter tire dates. Need every crop, or a different place? The full calendar covers 32 crops at 2697 stations.