Environment Canada is warning that the Toronto will experience freezing rain Saturday night following a dramatic drop in the temperature during the afternoon.
It says Pearson International Airport was hit with heavy rain about 2 p.m. after the temperature plunged over a two-hour stretch to 3 C from an unseasonably warm 11.8 degrees C in the morning.
It forecast that 20 to 30 millimetres of rain would fall in the Toronto area during the day followed by 10 to 20 mm in the evening, before switching to freezing rain about midnight.
Heavy rainfall warnings were also issued for Hamilton, St. Catharines, Ont., and Kitchener, Ont., which was also at risk of freezing rain in the evening.
To the north and east of Toronto, Environment Canada issued heavy rainfall and freezing rain warnings for Barrie, Ont., Peterborough, Ont., and Ottawa.
The unsettled weather is part of a system of severe storms stretching from the southern U.S. to eastern Canada.