SeaTac, WA Weather & Climate Normals
What a normal year in SeaTac actually looks like
On the 30-year record NOAA keeps for SeaTac, WA, the comfort score comes out to 56/100, strongly seasonal: Comfortable weather is limited to a shorter window; summers, winters, or precipitation swing wide. Only 5 months a year land in the 55–75°F range this site treats as mild.
How much SeaTac's weather actually swings
Average temperatures in SeaTac run from 42°F in Dec up to 67°F in Aug, a 25.3°F seasonal swing, a middling gap by national standards.
How wet SeaTac actually gets
Over a typical year, SeaTac sees about 39.34in of precipitation a year across roughly 156 days with measurable rain or snow, with 6.3in of snow a year.
SeaTac against the rest of the country
Out of 4876 cities scored here, SeaTac comes in at 752; within WA alone it ranks 43 of 125. Population is about 34,024.
Checking the actual forecast
These figures come from SEATTLE TACOMA INTL AP, WA US, the NOAA station 0.7 miles from SeaTac, averaged over 30 years, not tomorrow's forecast.
More on how this is worked out
Why this uses the nearest NOAA station · How the comfort score is calculated