Toronto is under a special weather statement on Sunday evening, along with much of southwestern Ontario.
Environment Canada is advising that "strong thunderstorms" that are over Michigan late Sunday are headed east, likely moving across Lake Huron and the border region around midnight.
These same storms may affect Toronto, as well as regions to the south and west of the city, all the way down to Windsor. Parts of cottage country are also affected by the special weather statement.
The weather agency says the thunderstorms could produce hail, torrential downpours and wind gusts of up to 80 km/h. Lightning is also a possibility.
If conditions change, Environment Canada says it will issue any necessary warnings or watches.