FloodZoneMap.org

Flash Flood — Williamson, IL

Apr 30, 2017

Significant flooding developed after two thunderstorm complexes crossed southern Illinois, bringing 72-hour rainfall totals to nearly one foot in isolated locations. A large complex of thunderstorms moved southeast across southern Illinois during the evening hours of the 29th. These storms occurred near a surface cold front which sagged southward across southern Illinois during the evening. During the overnight hours through the early morning of the 30th, an even larger complex of thunderstorms

Source: NOAA National Weather Service Storm Events Database (event 689588). Narrative written by NWS staff at the time of the event.

Flood Risk Context for Williamson, IL

This event is one of many recorded floods in Williamson County. See the full FEMA flood zone map, NFIP claim totals, and disaster history for the area.

View Williamson County flood data →

More Flood Stories

Flash Flood$25K damage

Williamson, IL · Jul 19, 2023

Major flash flooding struck parts of far southern Illinois. The hardest hit counties were Alexander, Pulaski, and Massac in the southern tip of Illinois.

Read the full account →
Flash Flood

Williamson, IL · Mar 11, 2021

Scattered thunderstorms tracked eastward from Missouri across southern Illinois. A deep upper-level low pressure system sank southeast into the far southwestern U.S., pumping plenty of Pacific moisture northeast into the mid Mississippi River Valley as a cold front settled…

Read the full account →
Flash Flood$50K damage

Williamson, IL · Apr 29, 2017

During the evening, clusters of storms developed just north of a surface warm front that extended from the Missouri bootheel northeastward along the Ohio River.

Read the full account →
Flood$40K damage

Williamson, IL · Apr 29, 2017

During the evening, clusters of storms developed just north of a surface warm front that extended from the Missouri bootheel northeastward along the Ohio River.

Read the full account →