Grab a sweater! Fall weather sets in this week
Sep 21, 2026, 6:06 AM
A closeup of fall foliage. (Photo courtesy of KIRO 7)
(Photo courtesy of KIRO 7)
Hopefully, you were able to get outside and enjoy the weather on this last weekend of summer. Fall officially begins Tuesday afternoon. And right on schedule, the weather is going to cool off noticeably this week.
For the rest of this evening, you can expect clouds to roll back over Puget Sound, and the overnight low temperature will drop to the lower 50s and upper 40s tomorrow morning. Monday will be a mostly cloudy day. The morning low clouds will lift by the afternoon, but mid- and high-level clouds will remain over the area, so I would expect only limited sunshine on Monday.
The high temperature tomorrow will be in the 60s around the islands and north of Seattle. There may be a few 70s on the thermometer to the south of Seattle.
On Tuesday, meteorologists will track another weather disturbance moving over the area, keeping the sky cloudy and possibly bringing some rain showers on Wednesday. If we do see showers in the area on Wednesday, they should be mainly observed to the north of Seattle. Temperatures will be held back into the 60s for the rest of the week.
Another weak system could come through on Thursday evening and on Friday with a chance of rain showers.
The big story this week will be the noticeably cooler temperatures. By the end of the week and into this coming weekend, the highs will only be in the mid to lower 60s.
Dig out the sweater and hoodie … fall is here.
