Toronto issued an extreme cold weather alert on Tuesday as temperatures were expected to plummet overnight.
The city's medical officer of health says the alert will remain in effect until further notice.
Environment Canada forecasts the weather to drop to -12 C overnight in Toronto with a wind chill of -17 C.
Meteorologist David Rodgers tells NEWSTALK 1010 those temperatures are certainly not the norm for Toronto this time of year.
"Temperatures are going to drop a lot. That's quite cold for mid November. It's quite possible we might set some low temperature records tonight."
The alert also activates services designed to get vulnerable residents inside.
The city says it will open a warming centre downtown at Metro Hall at 7 p.m.
The federal weather agency is also calling for flurries Tuesday night, with snow accumulation of up to two centimetres.
with files from Newstalk 1010