Seattle weather: Cloudy, cooler first week of fall in western WA

Published September 21, 2026 3:03 PM PDT

We are settling into a cooler, more fall-like weather pattern across Western Washington this week with more clouds and a chance of rain by Thursday night.

For Monday afternoon, expect a mix of clouds and sunshine as a weak system passes to the north. Temperatures will remain a little below normal, with highs in the 60s and low 70s.

More clouds Tuesday morning

Increasing onshore flow tonight will bring plenty of low-level moisture back into the region. That means low clouds will develop overnight, with a chance for some early drizzle Tuesday morning.

A map showing the overnight lows for Monday night in Western Washington.

It will be cool with increasing clouds Monday night in Western Washington. (FOX 13 Seattle)

Big picture view:

Stronger onshore flow should limit widespread fog, but low clouds will still be more widespread Tuesday morning. Those clouds should break up around midday, giving way to mostly sunny skies during the afternoon. Highs will drop to the 60s.

The autumnal equinox is at 5:05 PM on Tuesday.

A graphic counting down to the upcoming holidays.

Fall returns Tuesday at 5:05 PM. (FOX 13 Seattle)

Another system will approach the coast early Wednesday, but it's expected to weaken significantly as it moves inland. Most of Western Washington will stay dry, but there is a slight chance of a shower, especially north of Seattle. Otherwise, expect a mix of clouds and sunshine with highs back in the mid 60s.

Rain returns Thursday

What's next:

The biggest change of the week arrives Thursday, as a stronger frontal system moves toward Western Washington. Rain will move into the region by Thursday evening.

Rainfall totals could reach a half-inch to an inch along the coast, Olympics and Central and Southern Cascades, with roughly a quarter-inch to a half-inch possible across the interior. The North Cascades could see 1 to 1.5 inches of precipitation.

Snow levels will drop to around 6,000 to 6,500 feet, meaning some of the higher mountain peaks could pick up a few inches of snow.

The front could linger into Friday morning, keeping some light showers around early. Highs Thursday and Friday will only reach the low to mid-60s.

A 5 panel graphic showing expected rainfall in the Puget Sound area.

Rain returns to Western Washington Thursday night into Friday. (FOX 13 Seattle)

Cool, damp weekend ahead

The weekend looks quieter, but cool. Highs should remain in the low to mid-60s, with overnight temperatures in the 40s for most locations.

The 7 day forecast for the greater Seattle area.

It will be cooler and cloudier across Western Washington this week with rain returning Thursday night. (FOX 13 Seattle)

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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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