Smoke from wildfires raging in eastern Washington prompted an air quality warning for the Seattle area.
The National Weather Service said Saturday afternoon that air quality in parts of the Puget Sound region was unhealthy for sensitive groups.
The state Department of Ecology's air quality map showed those conditions in some measuring sites from Olympia to Mount Vernon as of 7 p.m. Saturday.
"An easterly wind direction has transported that smoke west of the Cascades," the Weather Service said. "The smoke has descended lower to the ground and is producing air quality concerns across Western Washington."
The statement said the worst conditions were in the valleys of the North Cascades and south of Centralia. It warned of similar conditions Sunday until a wind shift from the west in the afternoon begins to push the smoke back east.
The largest wildfires in eastern Washington have charred hundreds of thousands of acres.
The state's biggest fire is the Okanogan Complex, burning from the Methow Valley to Omak. The federal Incident Information System listed the fire's size Saturday afternoon at 227,206 acres.
That's nearly the size of last year's Carlton Complex, the largest fire in Washington state history. It burned more than 250,000 acres and destroyed hundreds of homes.
Authorities haven't been able to provide a full accounting of how many buildings have been lost in the Okanogan fire and the other major blazes in Washington state.
Fires around Lake Chelan have burned nearly 140,000 acres, and the North Star fire on the Colville Indian Reservation covered 132,000 by Saturday evening, according to the Incident Information System.
The changing wind could also mean problems for firefighters. The Weather Service in Spokane said a red flag warning for critical fire conditions would be in effect from Sunday afternoon to Monday night.