Issued just before 5 a.m., the statement warns that periods of "brief freezing rain" are possible this morning for the following areas:
- Areas west of Toronto including Mississauga, Oakville and through to Kitchener and London.
- Inland portions of Southern Durham region.
- Higher ground in the Hamilton and Niagara regions, as well as over Oxford - Brant.
- A large swath of area from Lake Huron for Peterborough.
Environment Canada meteorologist Jeff Coulson spoke to CBC news on Wednesday morning. He said the patchy freezing rain could pose a challenge for drivers.
"Some of those roadways that do look wet could in fact be icy," he said.
Coulson said he expects the freezing rain will mainly be a factor in the morning and will turn to rain in most areas later in the day as temperatures rise.
"Around noon most places should be above freezing and should just be getting it falling as straight rain," he said.
The weather forecast also calls for periods of rain and a high of 5 C today.
Flight delays possible
Porter Airlines issued a statement Wednesday saying the weather could result in flight delays. Travellers are asked to check their flight status online here.