109 flood insurance claims·$443,119 paid·5 federal flood & hurricane disasters
Share of the whole county outline, rivers and lakes included; parts FEMA hasn’t mapped count as zero.
Shaded areas are FEMA’s mapped flood hazard zones in and around Union County, Illinois. Zoomed out they are simplified; at street level the map switches to FEMA’s exact layer. Tap anywhere to check that spot, or search an address above.
Union County experiences a flood risk profile dominated by general river floods and flash flooding driven by heavy rainfall. Over a 30-year period, NOAA recorded 43 flood events and 26 flash flood events, resulting in two flash flood fatalities. Severe weather systems frequently produce heavy precipitation over saturated soils, leading to rapid runoff and localized inundation. Recent events include a strong storm system that brought widespread flooding and 2 to 5 inches of rainfall in January 2020, as well as heavy rainfall from nearly stationary storms that caused flash flooding in July 2024.
National Flood Insurance Program claims data indicates that risk is heavily concentrated in specific hazard zones. Zone A accounts for the vast majority of claims with 94 filed, resulting in an average payout of $5,540 and an average recorded water depth of 6 inches. Properties with unknown flood zones also face risk, accounting for 14 claims with an average payout of $2,724 and an average recorded water depth of 4 inches.
Homeowners, real estate agents, and journalists should pay the closest attention to properties located within FEMA Zone A, as well as structures in unmapped or unknown zones, where historical claims demonstrate consistent vulnerability to rising waters.
Summary written from NOAA storm reports and NFIP claims for this county. Not a prediction.
1% of Union County’s flood insurance claims were on properties rated outside FEMA’s high-risk zones.
95 NFIP claims with a recorded rated flood zone, 1978 to date. The zone is the one FEMA used to rate that policy, which may not match today’s map. Source: OpenFEMA NFIP claims.
In flood insurance claims here that reported a flood depth, the average was 5 inches.
Drawn to scale against an 80-inch door. Even a few inches soaks flooring, the bottom of the drywall and anything plugged in near the floor.
Average of the depths reported on claims (zero and implausible values left out); FEMA’s record doesn’t say exactly where each depth was measured. Source: OpenFEMA NFIP claims.
The worst year was 1993, with 43 claims and $14,380 paid, the year of Severe Storms & Flooding.
Bar height is scaled by square root so ordinary years stay visible next to the worst one. NFIP claims by year of loss. Source: OpenFEMA.
28 NOAA storm reports from Union County describe what happened, in the words of the forecasters who covered it. Read the Illinois flood stories →
15 federal disaster declarations since 1969, 5 of them floods, coastal storms or hurricanes.
| Disaster | Began |
|---|---|
| Severe Storms And Flooding | Feb 24, 2019 |
| Severe Storms And Flooding | Apr 19, 2011 |
| Severe Storms, Flooding, And Tornadoes | May 8, 2009 |
| Severe Winter Storm | Jan 26, 2009 |
| Hurricane Katrina Evacuation | Aug 29, 2005 |
| Record/near Record Snow | Dec 21, 2004 |
| Severe Storms, Tornadoes, And Flooding | May 6, 2003 |
| Severe Storms, Tornadoes And Flooding | Apr 21, 2002 |
Weather and water disasters only; most recent first. Source: OpenFEMA Disaster Declarations.
69 since 1996: 26 flash floods and 43 river or area floods.
| Event | Date | Damage |
|---|---|---|
| Flash Flood | Jul 13, 2024 | — |
| Flood | Mar 31, 2023 | — |
| Flash Flood | Jun 30, 2020 | $100,000 |
| Flash Flood | Jul 17, 2020 | — |
| Flash Flood | Jan 11, 2020 | — |
| Flash Flood | Jun 16, 2019 | $30,000 · 1 killed |
| Flood | Mar 9, 2019 | — |
| Flash Flood | Feb 7, 2019 | — |
— = no damage estimate in the record. Source: NOAA Storm Events Database.
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 overnight as heavy rai…
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 leading edge of a corr…
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 was also a pool of m…
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 knots. Strong instabili…
National Weather Service narratives, lightly trimmed. Source: NOAA Storm Events Database.
Every colour on the map above is a place on this drawing: where the ground sits relative to the flood FEMA plans for.
If a building in Union County is in a high-risk zone (A or V) and its mortgage comes from a federally regulated or insured lender, or is federally backed, flood insurance is required.
Outside those zones it is optional, and often worth having: from 2014 to 2024 nearly one-third of NFIP claims came from outside the high-risk Special Flood Hazard Area. Since Risk Rating 2.0, NFIP premiums are set for each building, so the only reliable price is a quote: FloodSmart.gov or a local agent.