The severe storms that hit southern Ontario on September 2 and 3 caused an estimated $563 million in insured losses, according to Catastrophe Indices and Quantification Inc. (CatIQ).
The initial estimate, released October 8 and reflecting claims data three weeks after the event, covers commercial and residential property, auto claims and loss adjustment expenses.
The storms ended several days of heat and humidity and brought very large hail, damaging winds and torrential rain to a wide area from Windsor to Ottawa. Several tornadoes and downbursts were confirmed. Toronto was among the hardest-hit areas, with hail the size of ping pong balls, and winds strong enough to buckle part of the outdoor concert stadium at Downsview Park. Flash flooding closed major roads, and some drivers had to be rescued.
Unlike the flash flood that hit Toronto in July 2024, the main drivers this time were wind and hail rather than water, CatIQ said, although there was severe flooding in Vaughan, north of the city.
“It is rare to see storms of this intensity – particularly those featuring large hail – make a direct hit on Toronto,” said Caroline Floyd, director of CatIQ.
Floyd said the average personal property and auto claims are currently lower than for the 2024 flood, and that CatIQ would watch how the estimate develops as insurers process claims.
The September storms are the latest of several costly events this year. On October 6, CatIQ raised its estimate for the severe thunderstorms that hit southern Ontario and southern Quebec from June 30 to July 3 to $491 million, up from $439 million. Much of that loss came from basement flooding in Ottawa. CatIQ also issued a second estimate of $293 million for the Bald Range Fire near Summerland, BC, slightly lower than its initial figure.
The losses are showing up in insurers’ results. Intact and Definity this week reported a combined $850 million in third-quarter catastrophe losses. Definity cited the early September storm system as one of the contributors.
Hail and wind claims tend to involve roofs, siding, vehicles and commercial buildings rather than basements. For brokers, that shifts the claims mix towards auto physical damage and exterior property repairs, with a different set of policy questions from those raised by sewer backup and overland flooding.
The cumulative effect may matter more. With 2025 a relatively quiet year at about $2.4 billion in industry-wide insured catastrophe losses, some in the market expected personal property pricing to ease. A run of costly Ontario events in 2026 makes that less likely. Brokers in the Greater Toronto Area and Ottawa should be preparing clients for renewals that reflect this year’s losses.
