According to Environment Canada, conditions are favourable for the development of dangerous thunderstorms that may be capable of producing torrential rain.
Later this after, scattered thunderstorms are expected to develop across southern Ontario and “given the high heat and humidity a few of these thunderstorms could be intense resulting in localized torrential downpours.”
Thursday’s thunderstorms are expected to be slow moving, which means some locations could receive up to 25 to 50 mm of rain over a short period of time.
Environment Canada, advises fast-moving water on roads can sweep a vehicle away, while strong gusts of winds of up to 90 km/hr are possible.
Intense lightning is also likely with a developing thunderstorm and heavy downpours can cause flash floods and water pooling on roads.
The temperature is currently 31°C in Toronto, with a humidex reaching 43°C this afternoon.
The Office of the Fire Marshal and Emergency Management recommends that you take cover immediately if threatening weather approaches.