An extreme cold weather alert issued for Toronto on Tuesday was extended as temperatures dipped to -20C with the wind chill factor and continued around -15C without the wind.
The alert caused city services to spring into action.
An additional 80 additional sleeping spaces were opened in Toronto's shelters and transit tokens were handed out so the homeless could make their way to the centres.
The biting cold stung residents who only a few days ago were basking in spring-like temperatures and enjoying outdoor activities.
"I wasn't prepared," said one bundled-up woman. "I got used to the warm, beautiful weather coming in from the tropics."
"It's winter," said a more accepting resident. "It's Canada. It's normal."
Black ice made the morning commute treacherous for some motorists. Several cars landed in the ditch at one slippery spot on Highway 404 near Stouffville Sideroad.
The cold air swept into the region following freezing rain that wreaked havoc on roadways on Monday.
Toronto's first blast of winter contributed to more than 700 collisions around the GTA, police said.
Frozen railway switches also caused massive delays for GO Transit commuters on Monday.
But southern Ontario's deep freeze also meant opportunity for businesses which rely on snow.
Ski resorts north of the city were laying off staff just a week before.
On Tuesday, snow covered the slopes and resort operators were operating snow-making machines to build up a good base.
"We can literally put the snow guns on one run and at night and in the morning its ready to open," Meredith Youmans of Dagmar ski resort said.
"Just groom that snow and we've got a run ready to go."
