Local Hazard History
St. Louis faces a rare triple threat. It sits in the heart of tornado country: the May 27, 1896 "Great Cyclone" killed at least 255 people in about 20 minutes and remains the third-deadliest tornado in U.S. history, and as recently as the 2011 Good Friday tornado an EF4 tore through Lambert–St. Louis International Airport. Wedged at the confluence of the Mississippi and Missouri Rivers, the metro floods in two ways: slow river floods like the Great Flood of 1993, when the Mississippi crested at a record 49.58 feet at St. Louis, and sudden flash floods like July 26, 2022, when a record 8.64 inches of rain fell at Lambert in a single day — breaking a mark set in 1915 — and drowned two people in their vehicles. Less expected but potentially catastrophic is the earthquake threat: St. Louis lies within reach of the New Madrid Seismic Zone, where the 1811–1812 earthquakes (estimated magnitude 7 to 8) rang church bells as far away as the East Coast. The USGS estimates a 25–40% chance of a magnitude 6.0+ quake in the zone within the next 50 years.