U.S. flags fly in smoke-filled air, Wednesday, Aug. 15, 2018, at Snoqualmie Pass in Washington state. Public-health officials continued to warn of unhealthy air across many parts of the Pacific Northwest as wildfires sent thick smoke across the region, and the National Weather Service issued an air quality alert for much of Central and Eastern Washington and northern Idaho through Wednesday. (AP Photo/Ted S. Warren)
A man wears a mask on 36th and Division in southeast Portland, Ore., on Wednesday, Aug. 15, 2018. The Oregon Department of Environmental Quality on Tuesday issued several air quality advisories. It says air quality was unhealthy in the Portland region, as well as in areas including Pendleton, Grants Pass, Medford and Pendleton. (Mark Graves/The Oregonian via AP)
SEATTLE — Unhealthy air filled with smoke from wildfires blanketed the Northwest again on Wednesday.