CatIQ, a Toronto-based organization providing catastrophe insurance data, has released its fourth-quarter loss estimate for the flash flooding in southern Ontario in July 2024.
The updated estimate indicates an insured market loss of $991 million, six months after the event. This marks a slight decrease from the third estimate of $998 million, issued on October 28, 2024.
Personal property accounted for 77% of the total insured loss. The hardest-hit areas were Toronto and the Greater Toronto Area, where heavy rainfall overwhelmed sewer and drainage systems, resulting in widespread flooding in low-lying areas.
The updated report offers a detailed breakdown of property and motor losses by FSA. It also includes meteorological data, local rainfall totals, damage reports, and images from the event. A fifth update will be released on July 16, 2025, marking 12 months since the event.
The flash flooding between July 15 and 16 was triggered by heavy rainfall in southern Ontario, including Toronto and the Greater Toronto Area. Some areas recorded over 120 mm of rain, with Toronto Pearson Airport reporting 123 mm. The heavy rainfall was caused by a stationary boundary extending from northern Quebec through the Upper Great Lakes to Colorado, with moisture streaming northward from the Gulf of Mexico.
Laura Twidle, president and chief executive of CatIQ, commented on the event: “July’s flash flooding was the first of four major events to impact Canada in the summer of 2024. This event is currently the tenth costliest insured catastrophe in Canada’s history, ranking just behind the devastating Toronto flooding in 2013.
“In terms of total rainfall in a single day at Toronto Pearson Airport, this event ranks the fifth highest, while the 2013 floods hold the record with 126 mm,” she added. “Interestingly, while the total insured loss for each event is very similar, the average claim in Personal Property is approximately CAD 10,000 higher in 2024. This could reflect inflation and policy changes, as well as trends in the use of space in dwellings over the past decade.”
Twidle also expressed gratitude for the support from insurance partners in providing the critical data used to develop the estimates, emphasizing the importance of such information amid Canada’s changing climate and increasing frequency of catastrophic events.
