Heavy rainfall causes widespread flooding across GTA

A number of people had to be pulled to safety Saturday afternoon as heavy rain quickly flooded parking lots, streets, and highways across the Greater Toronto Area.

The torrential downpour also resulted in leaks at Toronto Pearson International Airport's two terminals. The airport said the water is under control, and cleanup is ongoing.

While the airport is operational, Pearson said the rain resulted in several flight diversions and ground delays. As of 11:15 p.m., more than 14 per cent of flights scheduled to arrive and depart were cancelled.

"This is having a major impact on passengers. Travellers are encouraged to check with their airlines before leaving for the airport," Pearson said in a post on social media.

Toronto and much of southern Ontario were under several weather advisories throughout the day, including tornado, severe thunderstorm and rainfall warnings.

The Environment and Climate Change Canada (ECCC) said some locations saw 100 millimetres of rain Saturday afternoon. Between 1991 and 2020, Toronto usually gets between 68.5 and 71.9 millimetres of precipitation in August.

Widespread flooding in Mississauga has left drivers stranded in their vehicles and people had to be rescued. (City of Mississauga)

"Additional rainfall is expected to result in further impacts tonight and Sunday," ECCC said in its rainfall warning advisory for Toronto.

" A slight lull in showers and thunderstorms is expected overnight before strengthening Sunday with daytime heating intensifying thunderstorms."

Ontario Provincial Police said Highway 427 between Highway 409 and Highway 401 was flooded, as well as the Islington on and off ramps to Highway 401.

The Don Valley Parkway off-ramp to Bayview Avenue was temporarily closed due to the flooding, the City of Toronto said.

Rushing waters quickly submerged roads. In Mississauga, several intersections had to be closed due to flooding. Crews from the city's fire department were busy responding to rescue calls, including a pedestrian clinging to a light post at a flooded Dundas and Queen Federica.

He was assisted by rescue workers and brought to safety. Several people, including children, also had to be rescued by firefighters from their vehicle that was stuck in knee-deep floodwater.

Mississauga firefighter carries a child to safety after their vehicle was submerged in floodwater on Saturday, Aug. 17, 2024. (David Ritchie for CTV News Toronto)

"We're working diligently to clean-up areas as quickly as possible," the City of Mississauga said. "Please allow space for City vehicles to operate."

Toronto police had to remind motorists not to drive through flooded waters after some vehicles were submerged. Police also reported flooding under some bridges across the city.

The rain also forced Woodbine Entertainment to cancel the rest of the King's Plate live racing due to "unsafe racing conditions."

The Toronto and Region Conservation Authority (TRCA) said it saw 81 millimetres of rain within an hour. The federal agency adds heavy downpours can lead to the pooling of water on roadways and flash floods.

Meanwhile, a tornado touched down in Ayr, Ont., causing widespread damage. A Home Hardware store had portions of its roof and walls torn off.

Environment Canada said rainy conditions are expected to continue until Sunday.

A member of Mississauga Fire Services rescues a stranded driver in Mississauga on Saturday, Aug. 17, 2024. (X/Mississauga Fire)

With files from CTV News Kitchener's Shelby Knox and Hannah Schmidt