A wave of thunderstorms that tore through Ontario and Quebec between June 30 and July 3 has caused $439 million in insured damage, according to a revised estimate from Catastrophe Indices and Quantification Inc. (CatIQ), published by the Insurance Bureau of Canada (IBC) on Thursday. The figure is up from CatIQ's initial estimate of $374 million, issued shortly after the storms, with the increase driven largely by growth in commercial-line claims as adjusters completed assessments over the following weeks.
The storms brought hail, damaging winds, torrential rain and flash flooding to communities stretching from Windsor and North Bay through Toronto and Peterborough to Montreal. The estimate covers insured losses from residential and commercial property and motor vehicles, including loss adjustment expenses.
No city was hit harder than Ottawa. The capital recorded 118 mm of rain at Ottawa International Airport on July 1, breaking its all-time daily rainfall record for July and contributing to widespread flooding and sewer backups.
Mayor Mark Sutcliffe described the event as one of the city's worst flooding events in 25 years, saying it caused more than double the property damage of the 2019 Ottawa River flood, which affected roughly 2,000 homes. City infrastructure official Tammy Rose said service requests tied to sewer backups, drainage issues and suspected basement flooding climbed from roughly 3,200 to more than 4,500 within a week of the storm.
"The growing cost of severe weather is being felt by households, communities, insurers and governments across Canada," said Maximilien Roy, IBC's vice-president of strategy, in the CatIQ release. "These storms underscore the need for greater investment in measures that reduce flood risk and better protect Canadians from future losses."
The Ottawa storm has already prompted a municipal response: the city has moved to boost funding for its flood compensation program, though officials are directing residents to file insurance claims first, according to Insurance Business Canada's earlier coverage of the city's grant expansion.
That coverage also points to a longer-running problem for brokers: a federal flood insurance program first promised in 2019, and reaffirmed in the 2024 budget with an April 2026 target launch, has missed that deadline with no new timeline confirmed.
The scale of the risk is part of a broader pattern this year. Insurance Business Canada has reported that 2026 had logged 14 declared catastrophe events through early August, with the season's pace running close to 2023's record year of 26 events. Losses from Canadian catastrophes, both insured and uninsured, have climbed roughly 9.4% annually since the 1980s, outpacing GDP, population and construction spending, according to a 2025 report from the Institute for Catastrophic Loss Reduction, cited by The Globe and Mail. IBC separately puts Canada's average annual insured weather losses at more than $3.7 billion over the past decade, up from $1.4 billion the decade before. 2024 was the costliest year on record, with insured weather losses topping $9 billion nationally.
Homeowners are already feeling that pressure at renewal. A Statistics Canada report found home and mortgage insurance premiums rose 45% nationally between December 2019 and December 2025, more than double the rate of overall inflation.
IBC is renewing calls on all levels of government to restrict development in high-risk flood and wildfire zones, fund community-level flood infrastructure, strengthen building codes and improve public information on mitigation steps.
