5 flood insurance claims·$37,443 paid
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 Hamilton 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.
Flash flooding from summer thunderstorms dominates the flood profile of Hamilton County, Illinois, accounting for 31 events compared to 16 standard floods over the last 30 years according to the NOAA Storm Events Database.
Recent activity includes slow-moving storms and mesoscale convective systems that produced torrential rainfall along the I-64 corridor. Specifically, an event on July 19, 2025, brought high precipitable water values and torrential rainfall rates to the area, while a shortwave trough and slow-moving storms caused additional flooding issues in the county on August 4, 2025.
National Flood Insurance Program records indicate minimal claim history across specific zones, including two claims in Zone A averaging a $15,711 payout with an average recorded water depth of 2 inches, two claims in Zone UNKNOWN averaging a $3010 payout with an average recorded water depth of 3 inches, and one claim in Zone X_UNSHADED with a $0 payout and an average recorded water depth of 0 inches. Property owners located in Zone A and unmapped or unknown zones should pay the closest attention to flood risks given the historical occurrence of flash flooding and localized torrential rainfall.
Summary written from NOAA storm reports and NFIP claims for this county. Not a prediction.
In flood insurance claims here that reported a flood depth, the average was 2 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 1987, with 1 claims and $26,900 paid.
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.
24 NOAA storm reports from Hamilton County describe what happened, in the words of the forecasters who covered it. Read the Illinois flood stories →
10 federal disaster declarations since 1989.
| Disaster | Began |
|---|---|
| Severe Storms And Flooding | Apr 19, 2011 |
| Severe Storms, Flooding, And Tornadoes | May 8, 2009 |
| Hurricane Katrina Evacuation | Aug 29, 2005 |
| Record/near Record Snow | Dec 21, 2004 |
| Severe Storms, Tornadoes And Flooding | Apr 21, 2002 |
| Severe Storms And Flooding | Apr 28, 1996 |
| Severe Storms, Tornadoes & Flooding | May 15, 1990 |
| Severe Storms & Tornadoes | Jan 7, 1989 |
Weather and water disasters only; most recent first. Source: OpenFEMA Disaster Declarations.
47 since 1996: 31 flash floods and 16 river or area floods.
| Event | Date | Damage |
|---|---|---|
| Flood | Jul 19, 2025 | $10,000 |
| Flood | Jul 19, 2025 | — |
| Flash Flood | Jul 19, 2025 | $5,000 |
| Flood | Aug 4, 2025 | — |
| Flash Flood | Aug 4, 2025 | $5,000 |
| Flood | Dec 29, 2024 | — |
| Flash Flood | Mar 24, 2023 | — |
| Flood | Jan 18, 2023 | — |
— = no damage estimate in the record. Source: NOAA Storm Events Database.
Flood · Jul 19, 2025. As high pressure slowly crept northward towards the Quad State region, ridging remained over the middle Mississippi River Valley. A slow-moving MCS moved through the northeastern half of the Quad State midday to near sunset. CAPE rose to 1000-2000J/kg in northern portions of Southern Illinois with effective bulk shear around 30kts. Extremely high moisture content with precipitable water values of 2.25in resulted i…
Flash Flood · Jul 19, 2025. As high pressure slowly crept northward towards the Quad State region, ridging remained over the middle Mississippi River Valley. A slow-moving MCS moved through the northeastern half of the Quad State midday to near sunset. CAPE rose to 1000-2000J/kg in northern portions of Southern Illinois with effective bulk shear around 30kts. Extremely high moisture content with precipitable water values of 2.25in resulted i…
Flood · Aug 4, 2025. A shortwave trough and closed low reached the Quad State from the northwest during the morning of the 4th. The arrival of the shortwave preceded peak heating by several hours, limiting convective potential. Shear was very weak and instability limited. Slow-moving storms did produce torrential rainfall, with flooding issues reported in Hamilton County.
Flash Flood · Aug 4, 2025. A shortwave trough and closed low reached the Quad State from the northwest during the morning of the 4th. The arrival of the shortwave preceded peak heating by several hours, limiting convective potential. Shear was very weak and instability limited. Slow-moving storms did produce torrential rainfall, with flooding issues reported in Hamilton County.
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 Hamilton 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.