Warnings have now been issued ahead of a significant blast of winter weather that could dump up to 40 centimetres of snow in parts of southern Ontario starting tonight.
Environment Canada issued winter storm warnings on Sunday morning for most of southern Ontario, ahead of a low pressure system that will "significantly impact the Monday morning commute."
The snow is forecast to start falling late Sunday night and continue through Monday. Peak snowfall rates of two to five centimetres per hour are possible Monday morning, Environment Canada says.
Regions like Niagara Falls, St. Catharines, Welland, Grimsby, Kingston, Ottawa, Peterborough, Brockville, Tweed, and Cornwall are expected to receive between 25 and 40 centimetres of snow.
In Toronto, snowfall accumulations of 25 to 35 centimetres of snow is expected.
Pickering, Oshawa, Durham Region, Uxbridge, Beaverton, Vaughan, Richmond Hill, and Markham should expect similar snowfall amounts.
Meanwhile, Barrie, Orangeville, Kitchener, and Guelph are expected to receive less snow, with five to 15 centimetres forecast.
Drivers are being warned that rapidly accumulating snow during the peak of the storm will make travel difficult.
"Local blowing snow is also possible Monday afternoon and evening with gusty northerly to northwesterly winds," Environment Canada said.
Monday is the first day Ontario students are slated to return to in-person learning across Ontario.
Conditions are forecast to improve by Monday evening as the snow comes to an end.