US insurers have been hit with back-to-back catastrophe losses exceeding $1 billion each, after severe convective storms and historic snowfall tore through central and eastern states, Gallagher Re has warned.
The reinsurance broker said insured SCS losses from the events could still climb.
The firm estimated that outbreaks on both March 10-12 and March 15-16 each qualified as billion-dollar-plus industry loss events. "March continued to be a costly month for the U.S. SCS peril," Gallagher Re said, citing notable outbreaks on March 4, March 5-7, March 10-12, and March 15-16.
Straight-line winds swept more than two dozen states during the March 15-16 episode, accompanied by large hail and dozens of tornadoes. The National Weather Service reported thundersnow, flight cancellations, and widespread power outages. In Wisconsin, buildings collapsed after high winds compounded heavy snow loads.
The damage extends well beyond convective storms. Aon estimated industry insured losses in the billions from storms on March 5-7 and March 9-11, while State Farm and American Family reported receiving more than 38,000 claims from earlier March weather.
American Family has since logged over 2,300 claims from the March 14-16 systems alone, spokesperson Brandon Harrison said, with Ohio, Indiana, and Wisconsin worst affected.
In Nebraska, wildfires consumed some 827,000 acres, the office of Gov. Jim Pillen said. In Hawaii, storms triggered flash flooding and landslides across multiple islands.
SCS, the broad category covering tornadoes, hail, straight-line winds, and damaging thunderstorms, was long classified as a secondary peril. That framing is now hard to defend.
Aon's 2026 Climate and Catastrophe Insight report found that severe convective storms have overtaken tropical cyclones as the costliest insured peril of the 21st century, generating $61 billion in global insured losses in 2025 alone.
Research from Markel and the NAIC has shown hail accounts for roughly 70% of annual SCS catastrophe losses, with wind and tornadoes responsible for 20%.
March marks the start of the four-month peak for the peril. Since 2010, storms from March through June have cost insurers $390 billion, representing 72% of annual SCS losses, Gallagher Re said.
The string of catastrophe losses is also testing reinsurance programs. Gallagher Re has noted that any multi-billion-dollar US severe weather event could have "ramifications for certain aggregate reinsurance arrangements," including erosion of deductible layers beneath attachment points.
That pressure falls disproportionately on primary carriers. Moody's Ratings expects reinsurers to maintain elevated attachment points, stating that "insurers will continue to retain a large proportion of losses from secondary perils."
Writing in a December 2025 report, Swiss Re's Balz Grollimund urged the industry to take "the cumulative effect of frequent, low-loss events" more seriously, warning that rising property values and repair costs compound the risk.
Gallagher Re stressed the need for stronger building codes in high-risk states, noting that population and exposure growth has "helped exponentially grow the potential loss" from severe convective storms.
