Late-summer warmth returns to Seattle before cooldown this weekend

The weather on Thursday and Friday is going to offer a taste of late summer with plenty of sunshine.

Strong high pressure aloft building over the Pacific Northwest late this week, together with developing low-level offshore flow from east of the Cascades to the Pacific Ocean, is expected to push high temperatures into the 70s in many areas. Average high temperatures in mid-October are around 60 degrees.

The warm weather late this week will not even get close to the record high temperatures. On Oct. 16 (Friday), the record high temperature at Seattle-Tacoma International Airport (SEA) is 88 degrees, set in 2022. That temperature holds the all-time record for the warmest reading for so late in the year.

This summer-like weather late this week will offer another opportunity to enjoy fall tree colors and outdoor activities. Just keep in mind sunsets are now occurring a bit before 6:30 p.m., and by the end of the month, they will be earlier, before 6 p.m.

This weekend

Warm early fall weather is expected to change abruptly this weekend. The high-pressure system aloft is forecast to shift inland, opening the door for several Pacific weather systems to move ashore and bring cooler air and some precipitation.

The first weather system is expected to swing onshore Saturday and bring relatively light amounts of rainfall, ranging from under a half inch along the coast to up to a tenth of an inch from the Puget Sound area southward. High temperatures will cool to around 60 degrees, at least 10 degrees cooler than late in the work week.

Sunday will be the drier day of the weekend before the following weather system arrives Sunday night and lingers into Tuesday. This system is forecast to bring more rain and cooler temperatures, with highs mainly in the mid-to-upper 50s. Snow levels in the north and central Cascades are anticipated to fall to near 5000 feet.

Cooler, wetter, more seasonably fall-like weather is expected to continue through the rest of next week. In the meantime, enjoy the late-summer taste of weather Thursday and Friday.

Ted Buehner is the KIRO Newsradio meteorologist. Follow him on X and Bluesky. Read more of his stories here.