Which 2005 hurricane became the costliest on record at the time?

Hurricane Katrina became the costliest hurricane on record at the time in 2005. Its estimated damage reached about $125 billion, largely across Louisiana, Mississippi, and the wider Gulf Coast.

Katrina formed on August 23, 2005, and rapidly strengthened over the unusually warm waters of the Gulf of Mexico, briefly reaching Category 5 intensity. It weakened before making its final landfall near Buras-Triumph, Louisiana, on August 29 as a high-end Category 3 hurricane. The storm’s enormous size, storm surge, and levee failures caused catastrophic flooding in New Orleans.

Katrina surpassed Hurricane Andrew’s previous U.S. damage record. It later became tied with Hurricane Harvey as the costliest Atlantic tropical cyclone on record in nominal dollars. Hurricane Rita and Hurricane Wilma were also major 2005 storms, but neither was the answer to this cost-record question. Katrina caused 1,392 deaths, making it one of the deadliest U.S. hurricanes in modern history.