Ontario has plunged into a deep freeze, with extreme cold temperatures and snow squalls.
  
Environment Canada has issued wind-chill warnings for every major centre in southern Ontario, including Toronto, London, Hamilton, Milton, Durham Region, York Region and Waterloo — where it feels like -30 C.

Toronto has issued an extreme cold-weather alert, which goes into effect any time the temperature dips to dangerous levels and is aimed at getting the homeless off the streets and into shelters.

The city opens an additional 80 emergency shelter spaces, and has vans patrolling city streets checking on homeless people and providing them with transportation to shelters.

"Again today [Monday], all the shelters will have relaxed curfews, another outreach team will be out on the road overnight, drop-ins will have TTC tickets available for people to get to shelters if they're at a drop-in. And several organizations that work with homeless people will activate their own extreme cold weather plans," said Elaine Smyer, manager for emergency planning for the city.

The weather is not much better in the rest of southern Ontario. In the Sarnia, Elgin County, Haldimand, Niagara, Innisfil, Barrie, Pembroke and Algonquin areas, the wind chill is making it feel like -27 C to -29 C.

Blowing snow making driving difficult

Not surprisingly, it's even colder in northern Ontario — but not that much colder. In Sudbury and Thunder Bay, temperatures with the wind chill feel like -36 C and -37 C, respectively.
  
In the Owen Sound, Barrie and Picton areas, snow squalls and blowing snow warnings are in effect. Some roads in the counties have been closed because of whiteout conditions.

"The blowing snow, the high winds with the blowing snow, make driving very treacherous, and that has calmed down some [Monday] morning, but there are some roadways that remain closed north of Barrie," said Const. Julia McQuaig of the OPP.

"We [are] advising people to stay off the roadways due to severe winter weather conditions leading to very hazardous driving," said McQuaig.

Conditions aren't expected to improve any time soon.

Environment Canada is calling for continued extreme cold, coupled with more snow over the next few days.

With files from The Canadian Press