SEATTLE — Western Washington has been feeling the heat this week, capped off by what’s now officially the hottest day of the year for the Seattle area.
Temperatures topped out at 95 degrees at Sea-Tac Airport, just short of the 96-degree record for the day set on Aug. 15, 2010.
Meanwhile, fire danger remains high, with King County issuing a Stage 2 burn ban on Tuesday. That means no outdoor fires like backyard fire pits or campfires using chopped firewood or charcoal.
Thankfully, things are expected to gradually cool down from here. On Wednesday, the high pressure ridge responsible for the heat will be weakening over us, and that means a degree or two off the highs from today, but still it will be very hot with 80s and 90s widespread. The forecast high of 92 in Seattle would make it the fifth 90-degree day this year. The coast will again be much cooler.
Smoke from Cascades wildfires should mainly stay east of the area, as winds aloft begin to increase from the west.
On Thursday, we start the process of getting cooler marine air into Western Washington interior lowlands, including Puget Sound, though it’s not likely to be enough to keep highs from getting into the upper 80s to near 90 from Seattle south. By Thursday night, the onshore breezes will pick up and cooler air will arrive by Friday with highs back in the 70s to near 80.
During this transition to cooler weather in the lowlands west of the Cascades, winds will pick up and humidity will stay very low east of the Cascades, and a Fire Weather Watch has been issued starting Thursday for Douglas, Chelan, and Kittitas Counties. This will likely become a Red Flag Warning by Thursday, lasting into Friday. West of the Cascades, winds won’t be very strong but it could be breezy up north. The good news for Western Washington is that the cooler marine layer air will have more humidity.
Over the weekend, expect a mix of clouds and sunshine and highs in the 70s to low 80s in the lowlands. The chance of rain through the next seven days is very slim, with only the potential for some pockets of drizzle in the early morning hours over the weekend in a few spots, mainly coast and north.