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SeaTac weather

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SeaTac weather alerts and warnings

active National Weather Service watches, warnings and advisories

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SeaTac weather in numbers

from 30 years of measured normals

SeaTac swings 45°F across the year, from 80°F highs in July to 35°F lows in February, and December is usually the wettest month in a year that brings about 51 in of precipitation.

Warmest month
July
80°F average high
Coldest month
February
35°F average low
Wettest month
December
51 in a year
Below freezing
Never
overnight lows stay above 32°F
Comfortable
4 months
May, June, August and September
Residents
28,000
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The weather map: all three models at once

NWS, American, European side by side around SeaTac and nearby towns.Live rain radar →
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SeaTac hourly forecast: next 14 hours

consensus of the three models

Rain in the next 24 hours, model by model

each model's own hourly precipitation, side by side

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SeaTac 10-day forecast, out to 14 days

where the models agree, and where they split

SeaTac, Washington (WA) is at its warmest in Jul (average highs near 80°F) and coldest in Feb (lows around 35°F), with roughly 51 in of precipitation across the year. Below, compare what NWS, American, European forecast for SeaTac right now, and see exactly where they disagree.

We grade every model against the weather that actually happened, so you can see which forecast model is most accurate in United States before you trust any single number.

SeaTac climate by month

average daytime high and overnight low across a typical year
Jan
46°
36°
Feb
46°
35°
Mar
51°
36°
Apr
54°
40°
May
65°
47°
Jun
69°
51°
Jul
80°
57°
Aug
78°
57°
Sep
70°
53°
Oct
60°
46°
Nov
50°
39°
Dec
48°
39°

Which forecast is most accurate in SeaTac?

CheckWeather Score, graded against the weather that actually happened
ProviderCheckWeather-scoreTempWindRainRun by
European logo
European ★ Best
88
/100rank #1
83±1.7°F95±1.5 mph8994% hitECMWF - European Centre for Medium-Range Weather ForecastsReading, United Kingdom
American logo
American
80
/100rank #2
83±1.7°F95±1.4 mph6581% hitNOAA / NCEP (United States)College Park, Maryland, USA

The CheckWeather Score blends temperature, wind and rain accuracy, each measured against ERA5 (the recorded weather) over the last 30 days across 1999 cities. Lower error means a higher score. See which forecast model is most accurate in United States, how we measure forecast accuracy, or which model each weather app uses.

What do you think of the forecasts?

your vote counts

The accuracy above is the measured record. This is your opinion: which forecast service do you trust most in United States? Give each 1 to 5 stars.

NWSNational Blend (NBM)
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AmericanNOAA GFS
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EuropeanECMWF
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One vote per service. Anonymous: we store no personal data, only a one-way hash of your connection for a day to stop double votes.

Common questions

What's the weather in SeaTac today?
On this page we show what NWS, American, European each forecast for SeaTac today, side by side and updated live. When all three agree the forecast is reliable; when they split, we flag it so you know the day is genuinely less certain.
Will it rain in SeaTac today or tomorrow?
Check the hourly strip and 7-day forecast above. We compare rain from NWS, American, European for SeaTac and flag the days where the models disagree on whether showers actually arrive, which is exactly when a single app can catch you out.
Which forecast is most accurate for SeaTac?
Over the last 30 days, the European model has been the most accurate for SeaTac (CheckWeather Score 88/100), ahead of the American at 80. We grade every model against the recorded weather. See the US accuracy scoreboard for the full method.
What is the warmest month in SeaTac?
July is typically the warmest month in SeaTac, with average highs around 80°F.
How cold does SeaTac get?
The coldest month in SeaTac is February, when overnight lows average about 35°F.
How much rain does SeaTac get?
SeaTac sees roughly 51 in of precipitation a year, with December usually the wettest month.

Nearby

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