A powerful rainstorm swept through the Greater Toronto Area (GTA) on Saturday afternoon, flooding streets, highways, and parking lots, and forcing emergency crews to carry out multiple rescues as water levels rose rapidly in several communities.
The intense downpour caused significant disruption at Toronto Pearson International Airport, where leaks were reported in both terminals. Airport authorities said the situation was brought under control and cleanup efforts were ongoing. Although the airport remained operational, the severe weather led to several flight diversions, ground delays, and widespread cancellations. By 11:15 p.m., more than 14 per cent of scheduled arriving and departing flights had been cancelled.
“This is having a major impact on passengers,” Pearson Airport said in a social media post, urging travellers to check with their airlines before heading to the airport.
Toronto and much of southern Ontario were under multiple weather advisories throughout the day, including tornado, severe thunderstorm, and rainfall warnings. Environment and Climate Change Canada (ECCC) reported that some areas received up to 100 millimetres of rain in a matter of hours well above Toronto’s typical August average of 68.5 to 71.9 millimetres for the entire month.
Flooding was particularly severe in Mississauga, where drivers were stranded in submerged vehicles and emergency crews responded to numerous rescue calls. Firefighters assisted a pedestrian who was clinging to a light post at the flooded intersection of Dundas Street and Queen Federica Drive. Several people, including children, were also rescued from a vehicle trapped in knee-deep water.
“We’re working diligently to clean up affected areas as quickly as possible,” the City of Mississauga said, asking residents to give space to city crews responding to the emergency.
Major roadways were also impacted. Ontario Provincial Police reported flooding on Highway 427 between Highways 409 and 401, along with the Islington on- and off-ramps at Highway 401. In Toronto, the Don Valley Parkway off-ramp to Bayview Avenue was temporarily closed due to high water levels, and police warned motorists not to attempt driving through flooded roads after several vehicles became submerged. Flooding was also reported beneath multiple city bridges.
The Toronto and Region Conservation Authority (TRCA) said it recorded 81 millimetres of rain in just one hour, warning that such heavy rainfall can quickly overwhelm drainage systems and lead to flash flooding and dangerous road conditions.
The storm’s impact extended beyond flooding. Woodbine Entertainment cancelled the remainder of the King’s Plate live racing events, citing unsafe racing conditions. Meanwhile, a tornado touched down in Ayr, Ontario, causing widespread damage, including tearing off portions of the roof and walls of a Home Hardware store.
ECCC warned that the threat was not over, noting that additional rainfall could lead to further impacts overnight and into Sunday. While a brief lull in showers was expected overnight, forecasters said thunderstorms could intensify again Sunday with daytime heating.
Authorities continue to urge residents to remain cautious, avoid flooded areas, and monitor weather updates as cleanup and recovery efforts continue across the region.
