Midwest Derecho Pushes 2026 US Storm Losses Past $35 Billion
Aon and Gallagher Re estimate the August derecho's insured losses in the single-digit billions, pushing 2026 US severe storm losses past $35 billion and concentrating claims in Illinois's homeowners market.
The August 9-12 derecho has pushed 2026 year-to-date US severe convective storm losses past $35 billion, Gallagher Re said, with Aon and Gallagher Re both putting the storm's insured losses in the single-digit billions. Gallagher Re's tally covers public and private insurance.
The storm line swept from Iowa to Kentucky on August 11, with straight-line winds near 90 mph through Chicago's southern suburbs and northwest Indiana. Aon said the storm spun off 11 tornadoes, including an EF-2 with peak winds of 115 mph, and left more than 1.1 million power outages across Illinois, Indiana and Ohio. Wind damage was substantial, with torn-off roofs and submerged vehicles, while towns in Indiana and Ohio saw enough rain and flooding to prompt states of emergency. Consecutive high-wind days compounded the damage in Chicago's southern suburbs and northwest Indiana, and back-to-back storms in Ottawa on August 10 and 12 added further damage and outages.
Illinois's concentrated homeowners market
Gallagher Re counts the August outbreak as at least the sixth billion-dollar-plus severe convective storm event of the year. The total count has eased slightly: 11 such outbreaks in 2023, 10 in 2024, seven in 2025.
Guy Carpenter noted the derecho could rank among the ten costliest US severe convective storms since 1995; the current tenth-place event, a 2014 central US hail and windstorm, caused $5.1 billion in insured losses.
Illinois, the state absorbing the worst of the damage, is among the more concentrated homeowners markets among storm-prone states. State Farm Group wrote 33.68% of the state's homeowners multiperil premium in 2025, more than the combined share of Allstate at 14.27% and Country Financial at 7.79%, according to BestLink data. The concentration means a disproportionate share of Illinois claims is likely to land with a handful of carriers, a pattern less pronounced nationally.