FloodZoneMap.org

Union County, Illinois Flood Zones

Check an Address in Union County

Enter any address in Union County, Illinois to see its FEMA flood zone

The Flooding Character of Union County

Flash flooding from heavy rainfall events is the primary flood concern in Union County, IL. The NOAA Storm Events Database recorded 43 flood events and 26 flash flood events in the county over the last 30 years, with flash flooding resulting in two fatalities. Recent examples include flash flooding in July 2024 near Tamaroa and Murphysboro following torrential rainfall, and widespread flooding in January 2020 across southern Illinois, including Union County, due to heavy rainfall of 2 to 5 inches.

National Flood Insurance Program (NFIP) data shows that properties in Zone A, designated flood hazard areas, have experienced the majority of claims, with an average payout of $4,542 and an average water depth of 1.7 feet. While Zone X_Unshaded areas have had fewer claims, one claim averaged $6,002, indicating potential for significant damage even in lower-risk zones. Residents in designated flood zones (Zone A), those near waterways, and homeowners in areas with unknown flood risk should pay particular attention to flood preparedness.

Summary generated from NOAA storm narratives and NFIP claim data for this county. Not predictive.

Read First-Hand Flood Stories from Union County

28 NOAA storm reports from this county describe what happened, in the words of the meteorologists who were there.

Read Illinois flood stories →

Flood Risk Data for Union County

Union County, Illinois has recorded 69 flood-related events since 1996 according to NOAA's Storm Events Database, including 26 flash floods and 43 river or area floods. The county has received 15 federal disaster declarations, 5 of which involved flooding or coastal storms. Enter any address above to check its FEMA flood zone designation.

Union County Disaster History

FEMA Disaster Declarations (1969–2020)

Disaster Declarations
15
Flood/Coastal Disasters
5
Latest Disaster
Covid-19 (2020-01-20)

Source: OpenFEMA Disaster Declarations Summaries.

Recent Disaster Declarations in Union County

DeclarationTypeDate
Covid-19BiologicalJan 20, 2020
Covid-19 PandemicBiologicalJan 20, 2020
Severe Storms And FloodingFloodFeb 24, 2019
Severe Storms And FloodingSevere StormApr 19, 2011
Severe Storms, Flooding, And TornadoesSevere StormMay 8, 2009
Severe Winter StormSevere StormJan 26, 2009
Hurricane Katrina EvacuationHurricaneAug 29, 2005
Record/near Record SnowSnowstormDec 21, 2004
Severe Storms, Tornadoes, And FloodingSevere StormMay 6, 2003
Severe Storms, Tornadoes And FloodingTornadoApr 21, 2002

Recorded Flood Events in Union County

NOAA Storm Events Database (1996–2025)

Total Flood Events
69
River/Area Floods
43
Flash Floods
26
Total Property Damage
$5.0M
Flood Deaths
2

Source: NOAA National Weather Service Storm Events Database.

Recent Flood Events in Union County

TypeDateDamage
Flash FloodJul 13, 20240.00K
FloodMar 31, 20230.00K
Flash FloodJun 30, 2020100.00K
Flash FloodJul 17, 20200.00K
Flash FloodJan 11, 20200.00K
Flash FloodJun 16, 201930.00K (1 deaths)
FloodMar 9, 20190.00K
Flash FloodFeb 7, 20190.00K
FloodMay 1, 201930.00K
FloodJun 1, 2019500.00K

Union County Flood History

Flash Flood — Jul 13, 2024

Isolated thunderstorms developed during the afternoon hours on the 12th in the Quad State. Wind damage occurred in the town of Sesser, including tree and powerline damage. Storms from the previous evening in Sesser might have made some trees more susceptible to damage. Meanwhile, torrential rainfall with nearly stationary storms near Tamaroa produced flash flooding. Isolated storms continued ov...

Flood — Mar 31, 2023

Isolated severe thunderstorms, including a couple of supercells, produced several damaging wind events and large hail. A potent 500 mb jet streak ejected east-northeast from the Texas panhandle and western Oklahoma to the south of a mid-level low over northern Nebraska. A 992-mb surface low over western Iowa deepened as it moved into the upper Mississippi Valley. The storms formed along the le...

Flash Flood — Jun 30, 2020

Large clusters of thunderstorms during the early morning hours produced locally excessive rainfall. The storms occurred ahead of a very compact disturbance in the upper levels of the atmosphere over areas of far west central Illinois. A shortwave trough axis extended south from the disturbance. The air mass across the region was very moist, with precipitable water values around 2 inches. There ...

Flash Flood — Jul 17, 2020

Showers and thunderstorms developed along a surface warm front that lifted slowly north across western Kentucky and southern Illinois in the afternoon. Soils were quite saturated from recent heavy rains, causing rapid runoff and isolated flash flooding. Precipitable water values ranged from 2 to 2.25 inches along the front. The heavy rain potential was limited by weak 850 mb winds around 10 kno...

Flash Flood — Jan 11, 2020

An unseasonably strong storm system impacted the region January 10-11. Heavy rainfall, flooding, isolated damaging winds, a brief tornado, and gusty non-thunderstorm winds impacted southern Illinois during this time. The bulk of the event occurred overnight and into the morning hours on the 11th. Rainfall totals ranged from 2 to 5 inches, which resulted in widespread areal flooding and isolated...

Source: NOAA National Weather Service Storm Events Database.

Union County NFIP Flood Insurance Claims

Total Claims Filed
89
Total Paid Out
$375,740
Avg Claim
$5,292
Avg Water Depth
6.0 ft

Claims by Flood Zone

A Zones (High Risk)
75
X Unshaded (Low)
1

Source: OpenFEMA NFIP Individual Claims (2.25M records analyzed).

Flood Zone Types in Union County

FEMA assigns flood zone designations to areas in Union County, Illinois:

AE High Risk — 1% annual chance of flooding. Insurance required.

VE Very High Risk — Coastal flooding with wave action.

X (Shaded) Moderate Risk — 500-year floodplain.

X Low Risk — Outside major floodplains.

View all flood zone types →

Flood Insurance in Union County

Properties in Union County, Illinois that are in FEMA-designated Special Flood Hazard Areas (zones A and V) with federally backed mortgages are required to carry flood insurance.

Even outside high-risk zones, flood insurance is recommended. From 2014 to 2024, nearly one-third of NFIP claims came from outside the high-risk Special Flood Hazard Area.

Visit FloodSmart.gov to find an agent and get a quote.