Forest fires burning in northern Canada were blamed for haze over Calgary.
Wind is pushing the smoke south, said provincial wildfire information officer Anastasia Drummond.
"We had a bit of a cold front move through the northern portions of the province and what it did was push smoke that was burning from fires a little bit in northern Alberta, but most of which is in the Northwest Territories. That smoke has just been driven all the way south."
Police and fire fighters received many calls Sunday afternoon about hazy smoke over parts of the city. Alberta Environment's air quality index showed Calgary had a fair to good rating on Monday.
Drummond said she expects the smoke to clear up in a couple of days.