Toronto and much of southern Ontario are under a severe thunderstorm watch.
Environment Canada says conditions are favourable for the development of severe thunderstorms that may be capable of producing strong wind gusts, nickel-size hail and heavy rain.
“This line of thunderstorms is currently impacting southwestern Ontario and Lake Huron. This line of thunderstorms is expected to push through the region later this afternoon into this evening,” the advisory read.
In Toronto, 10 to 20 millimetres of rain could fall this evening.
“Heavy downpours can cause flash floods and water pooling on roads. Water-related activities may be unsafe due to violent and sudden gusts of wind over bodies of water,” Environment Canada said.
Showers are expected to continue overnight before ending early Thursday morning.
Toronto will then see a mix of sun and cloud, with a 40 per cent chance of showers and a high of 25 C. Wet conditions will continue Friday, with a 70 per cent chance of showers, but it will be cooler, with a high of 17 C.