Air Quality Improves, Cooler Weather Ahead For Puget Sound: Forecast

SEATTLE — A run of unseasonably hot and dry weather has come to an end, and the rest of September looks pretty normal, according to the National Weather Service.

Temperatures Saturday reached 92 degrees at the Seattle-Tacoma International Airport, marking the Emerald City's 13th day with temperatures at or above 90 for the year — the most on record. Afternoon highs slipped back into the mid-70s Monday and were on track to dip into the high 60s Tuesday, as clouds and a small chance for rain make a welcome return to the region.

After wildfires burning near Packwood, Skykomish and elsewhere in the state brought smoke to Western Washington over the weekend, degrading air quality to the "unhealthy" range for a broad portion of Puget Sound, conditions were markedly better Monday, with air quality readings on the low end of the "moderate" range. Forecasters expect onshore winds will help clear out the remaining smoke from most areas by Tuesday, returning air quality to the "good" level.

Thick smoke continued to impact firefighting efforts Monday at the Bolt Creek Fire, where up to 400 homes were under threat between Skykomish and Index as flames burned across 8,000 acres.

"Air quality will generally improve across western Washington this week," NWS Seattle wrote Monday. "Seasonable conditions are expected for the foreseeable future. This means generally cooler and wetter than the conditions we've experienced during the past several months. There is no signal for unusual temperatures or precipitation."

Though no major storms are on the horizon, near-term climate outlooks favor colder than usual temperatures and wetter conditions prevailing next week, well-timed for the arrival of the autumnal equinox.

Here is the five-day weather outlook for the Seattle area:

• Tuesday: 68°/56° (Cloudy, then sunny. Slight chance of showers.)
• Wednesday: 70°/56° (Partly sunny)
• Thursday: 70°/54° (Partly sunny)
• Friday: 68°/54° (Partly sunny)
• Saturday: 68°/55° (Mostly cloudy)