Blistering cold winds kept much of Ontario in a deep freeze Monday and meteorologists say there's no relief in sight.

Environment Canada issued wind chill warnings for many areas, with parts of eastern Ontario expected to feel as cold as –40.

A pigeon tries to warm itself on a heating grate in Toronto, where gusting winds made temperatures feel as cold as –28 C in the early morning.
(Dwight Friesen/CBC)

"It's a pipeline of arctic air coming down from the northwest … reaching all the way down to southern Ontario," said Environment Canada meteorologist Isabel Ruddick.

Ruddick says the extreme cold will moderate slightly around mid-week, but will be followed by another arctic blast next weekend.

Massive snow squalls expected

The blast of arctic air is not unusual for this time of year, says Ruddick, but what's unique is that the Great Lakes are above zero and have very little ice cover.

As the cold front moves over the milder waters, it's causing "massive snow squalls, very low wind chill values and the possibility of blizzard-like conditions [in the Lake Huron area]," she says.

The most intense snow squalls will likely be in the area extending from Wiarton east to Uxbridge, where five centimetres of snow is expected every hour.

Environment Canada says the snow squalls will drift southwest through the day.

Cities issue cold weather alerts

Winds gusted up to 50 kilometres an hour in some places, causing a wind chill of –30.

The frigid temperatures prompted several cities, including Toronto and London, to issue extreme cold weather alerts in effort to get the homeless out of the cold and into shelters.

In Ottawa, the city's medical officer of health issued a frostbite warning.

The cold also caused Dufferin-Peel Catholic District School Board to cancel school buses.

Provincial police said several roads had been shut down because of poor visibility and blizzard conditions in the counties of Bruce, Grey, Perth, Huron and Wellington

Sgt. Bruce Pritchard of the Orillia regional headquarters says there have been "a lot of cars in the ditch but we haven't had any serious injuries."

With files from the Canadian Press