Heavy rain in the forecast for much of southern Ontario today

Parts of the province could see as much as 75 millimetres of rainfall today, Environment Canada says.

With the exception of Toronto, much of southern Ontario, including areas north and west of the GTA, are under a rainfall warning this morning. Cambridge, Waterloo, London, and Owen Sound are included in the warning.

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The national weather agency said rainfall amounts of 50 millimetres are forecasted in affected areas today with “isolated amounts of up to 75 mm possible.”

“Rain, heavy at times, will taper off by late morning. Embedded thunderstorms are likely as well with very high rainfall rates possible,” the weather advisory read.

“Heavy downpours can cause flash floods and water pooling on roads. Localized flooding in low-lying areas is possible. If visibility is reduced while driving, turn on your lights and maintain a safe following distance.”

A weather advisory has not been issued for the Toronto area but wet weather is still in the forecast.

People carry umbrellas while walking during a downpour of rain in Toronto on Tuesday, Sept. 27, 2022. THE CANADIAN PRESS/Alex Lupul

Thunderstorms and heavy rain began early Thursday morning and showers are expected to continue until about noon. Thunderstorms and heavy rain began early Thursday morning and showers are expected to continue until about noon. The inclement weather this morning downed trees across the city and caused deep puddles in some areas.

A tree toppled on a residential street in Toronto following an early morning storm on Thursday, July 13, 2023.

The Toronto and Region Conservation Authority issued a watershed conditions statement on Thursday, warning of hazardous conditions near rivers and other bodies of water.

"Current weather forecast and rain already received suggests flooding from river systems is possible in TRCA watersheds," the statement read.

"Due to the total rainfall, all TRCA rivers within the GTA may experience higher than normal water levels and greater flows. The combination of slippery and unstable banks, and rising water levels could create hazardous conditions near rivers or other water bodies. Heavy rainfall could result in poor visibility and ponding of water in low lying areas or areas with poor drainage. All shorelines, rivers and streams within the GTA should be considered dangerous as this rainfall will result in higher flows and rapidly changing water levels." 

Toronto is expected to see a high of 23 C today but the temperature will feel closer to 29 with humidity.