Just one day after temperatures soared to 12C in southern Ontario, the region is expected to be hit with freezing rain, ice pellets and up to 15 centimetres of snow.
Environment Canada issued a winter storm warning Tuesday as a cold system made its way across Tennessee towards southern Ontario.
Toronto will be hit by about 10 centimetres of snow, forecasters predicted. Snow will begin to fall by early evening followed by ice pellets around midnight.
The snow is expected to change to freezing rain overnight, making the morning commute troublesome for motorists.
"This is an alert to the potential development of dangerous winter weather conditions in these regions," the agency said in a statement on its website. "Travellers should be prepared to alter plans accordingly again as driving conditions once again will deteriorate significantly tonight and Wednesday."
Areas north of Toronto, near Barrie through to Renfrew, could see up to 25 centimetres of snow.
Freezing rain and ice pellets will begin to fall in communities near Lake Erie by late Tuesday afternoon, Environment Canada said.
