The government of Ontario lifted a smog advisory for the city of Toronto and surrounding area Friday afternoon.
Toronto Public Health also lifted a heat alert for the city Friday morning.
Torontonians felt the heat Thursday as the temperature rose to 31C, beating the record 30.5C set on May 24 1991.
The heat alert was issued Thursday morning, and came with a warning that more severe, sustained high temperatures could increase the number of weather-related deaths.
The smog advisory was issued on Tuesday for much of southern and central Ontario. The Ontario Ministry of the Environment lifted advisories for northern parts of the province Friday morning.
When the province issues a smog advisory, it urges residents, especially those with respiratory problems, to refrain from heavy outdoor activity.
The four day smog advisory was Toronto's fifth of 2007. Thursday's heat alert was the city's first of the year, arriving five days earlier than it did last May.
Smog is less likely to form during cooler weather with cloud cover because there isn't as much sunlight to react with chemicals.
