Preliminary estimates indicate that combined economic and insured losses from severe convective storm (SCS) outbreaks in the United States between June 18-25, 2026, will likely land in the low single-digit billions USD, according to broking group Aon’s Weekly Cat Report.
The severe weather affected portions of the Gulf Coast, central United States, and High Plains from June 18–25, with the most significant impacts concentrated across southeast Louisiana, south Mississippi, the central Plains, and the Midwest.
The severe weather episode includes deadly tornadoes in Kansas and Illinois, and the long-track derecho from Kansas into Oklahoma and Arkansas.
Another key factor for this severe weather was the remnants of Tropical Storm Arthur, which produced a regional tornado outbreak with numerous weak-to-moderate tornadoes in Louisiana and Mississippi, while a subsequent episode from June 21–23 featured stronger tornadoes and a long-track derecho from Kansas into Oklahoma and Arkansas.
Aon notes that these 14 tornadoes across southeast Louisiana and south Mississippi were all rated EF0 or EF1. The strongest of these produced winds up to 105 mph (170 kph) in St. Tammany Parish, Louisiana, and Hancock County.
The re/insurance broker’s report explained that there was significant impact to residential, commercial, and infrastructure driven by additional localised wind damage in northern Illinois and northwest Indiana, and the significant hailstorm in Fort Morgan, Colorado.
While no fatalities were reported, two people were injured in Jefferson Parish. The worst impacts were in residential neighbourhoods where several homes sustained partial roof loss and collapsed walls, with damaged carports and significant tree damage reported.
Between June 21–23, a separate outbreak of severe weather and tornadoes occurred across parts of Kansas, Illinois, and Indiana. In rural Jefferson County, Illinois, around 90 miles (145 km) southeast of St. Louis, at least two people were killed in separate incidents involving mobile homes, and at least 20 homes were damaged.
In Sedgwick County, Kansas, an EF2 tornado blew a manufactured home off its foundation, killing one person. Tornadoes also tore through southern Indiana, where roughly 30 homes were damaged in Gibson County, explained Aon’s report.
The derecho that developed in northwest Kansas and tracked into Oklahoma and central Arkansas on June 22 damaged 6 homes in El Reno, Oklahoma and derailed a BNSF train in Woodward County.
Additional severe storms from June 24–25 brought localised wind damage, a brief tornado in northern Illinois, and a damaging hailstorm in eastern Colorado. Concentrated areas of straight-line wind damage were reported in and near Streamwood, Bartlett, and Hanover Park, Illinois, as well as in and around Griffith and Merrillville, Indiana.
The report stated that at least one brief tornado was observed near Huntley, Illinois, where video captured debris being lofted and swirled beneath a narrow funnel.
Further west, the hailstorm in Fort Morgan, Colorado, damaged multiple homes, vehicles, and public property. At Riverside Park, baseball-sized hail shattered windows at the City of Fort Morgan Parks Department building.
“The primary loss drivers over the June 18–25 period were the June 21–23 severe weather episode, including the deadly tornadoes in Kansas and Illinois and the long-track derecho from Kansas into Oklahoma and Arkansas, along with the June 18–19 tornado outbreak tied to Tropical Storm Arthur’s remnants in Louisiana and Mississippi. Additional localized wind damage in northern Illinois and northwest Indiana and the significant hailstorm in Fort Morgan, Colorado, contributed further to residential, commercial, and infrastructure impacts. Across the affected regions, preliminary estimates indicate that combined economic and insured losses from these events will likely reach into the low single-digit billions USD,” said Aon.
