Environment Canada issued the warning stretching from Windsor to the Hamilton and Niagara areas.
The weather agency is warning of strong southwesterly winds gusting to 90 or 100 km/h, developing Saturday afternoon and continuing into the evening before easing.
“There is also the risk of a brief thunderstorm late this afternoon, particularly over the Niagara peninsula. Isolated wind gusts greater than 100 km/h will be possible with any thunderstorm,” the weather agency said.
Environment Canada said that loose objects may be tossed, tree branches could break, and power outages could occur.
The Toronto area is not under a wind warning, but Environment Canada has placed the GTA under a special weather statement with wind gusts of 70 to 80 km/h expected Saturday.