Maps show where new plumes of smoke will cause hazy skies through the end of the week. Low-level smoke is forecast to spread eastward Wednesday across the Appalachians and into the Mid-Atlantic and Northeast.

Thick smoke from wildfires choking millions of Canadians and Americans was reported to have blown up to 7,000 kilometers, reaching Europe.

Smoke from Canadian wildfires carried another day of poor air quality south of the border to the American Midwest. Huge plumes of smoke have even reached Europe, the European Union's climate monitoring service said Tuesday.