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SeaTac, WA Weather & Growing Conditions

Local forecast, frost dates, hardiness zone and planting guidance for SeaTac, a city in King County, Washington.

Overnight
56°F
Clear
Clear, with a low around 56. North northeast wind around 7 mph.

7-day forecast for SeaTac

WhenTempForecastWindPrecip
Overnight 56°F Clear 7 mph NNE 0%
Tuesday 85°F Sunny then Areas Of Smoke 6 to 9 mph N 0%
Tuesday Night 60°F Areas Of Smoke 5 to 9 mph NNE 0%
Wednesday 90°F Sunny then Patchy Smoke 5 to 8 mph N 0%
Wednesday Night 61°F Mostly Clear 2 to 8 mph NNE 0%
Thursday 90°F Sunny 2 to 7 mph NW 0%
Thursday Night 62°F Mostly Clear 3 to 7 mph WSW 0%
Friday 87°F Sunny 6 mph SW 0%
Friday Night 60°F Mostly Clear 2 to 7 mph WNW 0%
Saturday 83°F Sunny 5 mph WSW 0%
Saturday Night 58°F Mostly Clear 2 to 7 mph NNW 1%
Sunday 78°F Mostly Sunny 5 mph WSW 1%
Sunday Night 57°F Mostly Clear 5 mph NW 1%
Monday 77°F Mostly Sunny 2 to 6 mph WNW 1%

Forecast source: National Weather Service (api.weather.gov) for SeaTac (47.443, -122.298). Updated through the day.

Growing snapshot for SeaTac

Last spring frost
Mar 2
First fall frost
Nov 23
Growing season
266 days
Hardiness zone
9a

More local growing data for SeaTac: nearby ZIP 98158 weather · frost dates · planting calendar · Washington frost dates

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Climate data from the nearest NOAA station, Seattle Tacoma Intl Ap, Wa (0.5 mi from SeaTac). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.