While the system crosses the region and the Great Lakes, the weather agency has predicted snowfall up to 10 centimetres overnight. The snow will then turn to freezing rain early Monday morning.
Areas further east near Ottawa will see freezing rain later in the day on Monday.
A glaze of ice has coated some areas from Lake Huron to the Greater Toronto Area.
Warnings from Environment Canada state that drivers should take extra caution with morning commutes, and should take extra time for travel.
Also, due to the freezing rain, they have also cautioned pedestrians to walk carefully on roads and sidewalks not treated for slippery conditions in the affected regions.