High Fire Danger, Smoke Concerns This Weekend: Puget Sound Forecast

SEATTLE — Western Washington has largely dodged wildfire smoke this season, but that luck may soon run out as the next burst of late summer heat arrives this weekend. The National Weather Service warns that red flag conditions will impact the region starting Friday, with high heat, low humidity and gusty winds in the forecast through the weekend.

A fire weather watch will be in effect from Friday morning through Saturday evening across Puget Sound, with relative humidity dropping as low as 20 percent in some places as temperatures warm into the high 80s and low 90s.

Forecasters expect Saturday will be the warmest in the three-day stretch, when afternoon highs could get close to 90 degrees at the Seattle-Tacoma International Airport — a rare feat for September. Sunday should knock a few degrees off before temperatures dip back into the 70s Monday.

According to the National Weather Service, even hitting 85 degrees in September is unusual, happening just 80 times over 77 years of records. Breaching 90 degrees is far less common, recorded just 16 times since the 1950s.

As the risk for new fires builds, Puget Sound may also see the season's first significant air quality impacts from wildfires burning elsewhere.

The Puget Sound Clean Air Agency expects air quality will degrade to the "moderate" or "unhealthy for sensitive groups" range Friday, Saturday and Sunday, with some chance for more significant impacts. Forecasters expect winds will shift by Monday, returning air quality to the good range.

Residents can find updated air quality forecasts via the Puget Sound Clean Air Agency and check for daily updates on the Washington Smoke Blog. Live wildfire smoke conditions are available using the EPA's AirNow tool.