The Canadian wildfires causing poor air quality in the U.S.

From coast to coast, uncontrollable blazes in nine of the country’s 13 provinces and territories have devoured millions of acres of forest, swallowed up hundreds of structures, forced more than 100,000 people from their homes and blanketed cities near and far from the flames in eerie clouds of toxic smoke.

The outbreak of so many blazes across the country at this time of year is “not normal,” officials here say — and the worst could be yet to come. If the rate of fire activity continues at its current pace, they said, the country will suffer the worst wildfire season in its recorded history. The amount of smoke pouring into the United States is also exceptional. Authorities from New York to Minnesota to Washington, D.C., have issued public health alerts and urged people to stay indoors and wear masks to protect themselves from potentially toxic fine particles in the air.