SEATTLE (AP) — Unhealthy air filled with smoke from wildfires blanketed the Northwest again on Wednesday.

Washington state had the worst air quality in the country, according to the National Weather Service.

In the central Washington cities of Chelan and Wenatchee the air quality Wednesday reached the hazardous level, prompting Chelan County officials to distribute masks.

The smoke reached levels that were unhealthy for everyone in Seattle and nearby areas, the Puget Sound Clean Air Agency said.

At Seattle's Kerry Park which usually offers picture-perfect views visitors were disappointed to find parts of Puget Sound hidden behind the smoke.

"In an ideal world, we would want to be able to see Mount Rainier in the background so the haze is basically killing that opportunity, unfortunately," Aidan Groll of Florida told KING-TV.

Public health officials warned of unhealthy air across the Pacific Northwest as wildfires sent thick smoke across the region. (August 15)

According to the National Interagency Fire Center, 13 large wildfires have burned more than 211 square miles (546 square kilometers) in Washington state this year, while in Oregon, 10 large fires have scorched over 256 square miles (663 square kilometers) the Seattle Times reported . About 600 wildfires are burning across British Columbia.

The Oregon Department of Environmental Quality said Wednesday that the air quality in Portland and Medford was unhealthy.

The weather service says cleaner air will begin pushing onshore in the western part of Washington and Oregon on Wednesday night.

An air quality alert for eastern Washington and northern Idaho has been extended into Friday morning.