A special air quality statement was issued for the Calgary area early Sunday morning.

"Smoke is causing locally poor air quality and reduced visibility," it said on the agency website, at 4:36 a.m.

Just before 8 a.m., the air quality health index for Calgary was seven, which is considered high risk.

Dozens of wildfires are burning out of control in the B.C. interior, including the Okanagan and Shuswap Lake areas.

Edmonton, where thousands are running a marathon Sunday, had an air quality health index rating of three, or low risk.

In its statement, Environment Canada added that "Some improvement is possible this afternoon for areas east of the foothills."

A number of major outdoor events are taking place in the Calgary area Sunday, including the final round of the Shaw Charity Classic, Expo Latino and the final night of Country Thunder at Fort Calgary, featuring headline act Keith Urban.