Seattle weather: Cooler with thunderstorms Saturday

Published August 21, 2026 3:21 PM PDT

Today brought increasing clouds as a southerly flow aloft wrapped around an upper-level low-pressure system in the Pacific. Despite the cloud cover, the afternoon stayed dry for most of Western Washington, although an isolated light shower or thunderstorm was possible.

Seattle weather will turn cooler Saturday as isolated showers and thunderstorms become more likely, especially compared with today.

Seattle weather could also see a little wildfire haze Saturday as winds, lightning and dry conditions increase fire concerns: however, air quality should stay good to moderate. (FOX 13 Seattle)

The bigger change arrived tonight and into Saturday, with a Fire Weather Watch posted for the Olympics and portions of the western slopes of the Cascades. Isolated showers and thunderstorms will be possible Saturday, and even a small amount of lightning could create new fire starts.

Seattle weather will remain relatively mild, but fire danger will increase as a Fire Weather Watch covers the Olympics and portions of the western slopes of the Cascades through Saturday.

Dangerous fire conditions will exist across Eastern Washington, where powerful winds and lightning could spark new fires this weekend. (FOX 13 Seattle)

Wildfire outlook in Washington

A Fire Weather Watch will also be in effect across much of eastern Washington Saturday and Sunday, where very powerful winds and lightning could create dangerous fire conditions. Even in Western Washington, a little wildfire haze will be possible Saturday, while air quality today remained generally good to moderate.

Temperatures will take a nosedive this weekend, with highs falling into the mid-70s Saturday and Sunday. Monday will stay in the mid-70s before temperatures climb to around 80 degrees Tuesday, followed by another stretch of mid-70s Wednesday and Thursday.

Seattle weather will cool into the mid-70s Saturday and Sunday, with a chance for isolated showers and thunderstorms Saturday.

Seattle weather will stay mild Monday, with highs again in the mid-70s and mostly manageable conditions. (FOX 13 Seattle)

Overall, the forecast will turn much milder and more moderate for much of next week, with the main shower and thunderstorm chances focused on Saturday.

Seattle weather will turn noticeably cooler this weekend, with highs in the mid-70s Saturday through Monday before temperatures reach around 80 Tuesday.

Seattle weather will stay mild and moderate through Thursday, with highs returning to the mid-70s. (FOX 13 Seattle)

Take good care,

Meteorologist Abby Acone and the FOX 13 Weather Team

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The Source: Information in this story comes from weather models interpreted by the FOX 13 Seattle weather team.

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