Seattle, WA – Unseasonable September heat grips Seattle today, with temperatures expected to climb to 87°F by the afternoon before relief arrives midweek. Commuters along I-5 should be ready for hazy skies early, as areas of smoke may reduce visibility through the morning commute. Hydrate often and avoid prolonged outdoor activity during peak afternoon heat.
According to the National Weather Service, Tuesday will start smoky, then turn sunny as north winds shift southeast. Conditions will cool Tuesday night, dropping to 59°F, before Wednesday ushers in a milder high of 76°F with lighter breezes. By Wednesday evening, skies turn partly cloudy, signaling the start of a pattern change.
The heat is unusual for mid-September, and health officials urge caution, particularly for vulnerable residents without air conditioning. King County Emergency Management recommends checking on neighbors and limiting strenuous outdoor work during today’s peak hours.
Thursday will stay mostly sunny with highs near 71°F, but by Friday the cooling trend deepens with highs in the mid-70s and clearer skies. The bigger change comes Saturday when rain chances return, breaking the dry streak. Sunday looks wetter, with widespread showers and highs in the upper 60s, a true sign of fall settling into western Washington.
Drivers should prepare for wet roadways this weekend, particularly on I-5 and SR-520, where slick conditions could slow traffic. With the transition to fall weather, local agencies remind residents to keep storm drains clear and review emergency kits ahead of the rainy season.
Showers may persist into early next week, reinforcing a shift away from the brief September heat wave. More advisories could follow as the pattern stabilizes.
Five-Day Forecast for Seattle, WA
- Wednesday: Sunny, high 76°F / low 56°F.
- Thursday: Mostly sunny, high 71°F / low 55°F.
- Friday: Sunny, high 74°F / low 56°F.
- Saturday: Rain chances, high 68°F / low 59°F.
- Sunday: Rain likely, high 68°F / low 55°F.
