In southern Ontario, areas such as Niagara, Toronto, and Collingwood, were experiencing southwesterly winds bringing mild air from the Gulf of Mexico, said Environment Canada. The Ottawa area also got mild weather after freezing rain overnight.
Toronto and London hit record highs of 14 C while Windsor saw a 15 C high early in the day, shattering the Jan. 30 record of 9.5 C set in 1988.
David Phillips, a senior climatologist with Environment Canada, said Toronto has seen erratic and highly unusual weather this month.
"It's about 15 degrees warmer than it should be for this time of the year," he said.
With the warm air, rainfall of 10 to 20 mm was also expected in southern Ontario, with higher amounts possible in locales that get a thunderstorm, along with some possible flooding.
Southern Quebec also got a round of warm and wet weather Wednesday, with about 15 to 30 mm of rain, and 40 mm or more possible north and east of Montreal, said meteorologist Jay Scotland at CBC's weather centre.
The warmth will be short-lived, however. An Arctic cold front will drag east into Quebec on Thursday, and temperatures are expected to plunge to below freezing again.
Meanwhile, the Maritimes saw snow, rain and strong wind gusts. Parts of southeastern New Brunswick have seen freezing rain and wind warnings of gusts up to 90 km/h.
The forecast prompted many schools in the Fredericton and Moncton areas to close for the day Wednesday.
On the Prairies, gusty winds and Arctic air blew toward the eastern provinces. Saskatchewan has been in the grip of another cold spell, with temperatures in the mid-minus 20s and wind speeds of 15 to 20 km/h.
RCMP in Prince Edward Island warned drivers to stay off the roads. Freezing rain moving west to east caused treacherous driving conditions Wednesday afternoon, prompting the P.E.I.'s English school board to hold students at school 1½ hours later than usual.
All provincial highways in and out of Sudbury, Ont., were closed Wednesday morning due to the extreme weather and poor road conditions but have since been reopened. Some highways were under water, while others were extremely icy, police said.
The blast of winter weather also had Air Canada, WestJet and Porter airlines warning of possible delays and cancellations at Toronto's Pearson and Billy Bishop airports.
The Rideau Canal Skateway in Ottawa was also temporarily closed.Suggest a correction