Wildfire smoke from Canada is blanketing the skies in the Midwest, leaving millions with dangerous breathing conditions.

The Midwest saw some of the worst air quality conditions in the world Thursday, and similar conditions are expected to persist for several days.

The elevated levels of fine particulate matter resulting from wildfire smoke could present significant health risks.

WASHINGTON — Strong storms that brought hurricane-force winds to an area stretching from the Upper Plains to the Midwest have ...