1,690 flood insurance claims·$15.7M paid·11 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 Calhoun 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 and general flooding dominate Calhoun County, with the NOAA Storm Events Database recording 15 flood events and 13 flash flood events over the last 30 years. These incidents are often driven by stalled fronts, low-level jets, and training thunderstorms. For example, a slow-moving frontal boundary dropped up to 8 inches of rain over a 24-hour period, causing considerable flash flooding in Calhoun County on June 25, 2015. More recently, on July 27, 2025, training thunderstorms fueled by moisture convergence flooded roads and washed out culverts.
NFIP claim data indicates that flood risks extend across multiple zones, with the highest concentration of historical impacts occurring in Zone A, which accounts for 1,204 claims with an average water depth of 9 inches and an average payout of $12,276. Properties in unmapped or unknown zones have also experienced repeated impacts, recording 378 claims with an average water depth of 3 inches. Homeowners, real estate agents, and journalists should pay the closest attention to properties located within Zone A and areas with unmapped or unknown flood designations, as these locations face documented vulnerability to both rising waters and localized flash flooding.
Summary written from NOAA storm reports and NFIP claims for this county. Not a prediction.
4% of Calhoun County’s flood insurance claims were on properties rated outside FEMA’s high-risk zones.
1,252 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 8 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 434 claims and $6.6M 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.
3 NOAA storm reports from Calhoun County describe what happened, in the words of the forecasters who covered it. Read the Illinois flood stories →
25 federal disaster declarations since 1969, 11 of them floods, coastal storms or hurricanes.
| Disaster | Began |
|---|---|
| Severe Storms And Flooding | Jun 29, 2023 |
| Severe Storms And Flooding | Feb 24, 2019 |
| Severe Storms, Straight-line Winds, And Flooding | Apr 16, 2013 |
| Severe Winter Storm And Snowstorm | Jan 31, 2011 |
| Severe Storms And Flooding | Jun 1, 2008 |
| Severe Winter Storm | Nov 30, 2006 |
| Hurricane Katrina Evacuation | Aug 29, 2005 |
| Severe Storms, Tornadoes And Flooding | Apr 21, 2002 |
Weather and water disasters only; most recent first. Source: OpenFEMA Disaster Declarations.
28 since 1996: 13 flash floods and 15 river or area floods.
| Event | Date | Damage |
|---|---|---|
| Flash Flood | Jul 27, 2025 | $50,000 |
| Flash Flood | Jun 19, 2021 | — |
| Flash Flood | Jun 25, 2015 | — |
| Flash Flood | Jun 21, 2015 | — |
| Flash Flood | Oct 2, 2014 | — |
| Flood | Apr 16, 2013 | $5,000 |
| Flood | Apr 12, 2013 | $1,000 |
| Flood | May 1, 2013 | $2,000 |
— = no damage estimate in the record. Source: NOAA Storm Events Database.
Flash Flood · Jul 27, 2025. During the night of July 26th-July 27th, moisture convergence along a low-level jet spurred convection in eastern Missouri. This convection developed in an environment primed for efficient and heavy rainfall. Thunderstorms trained over Calhoun County, causing roads to flood and culverts to wash out.
Flash Flood · Jun 19, 2021. An outflow boundary from earlier convection moved southward through region, triggering widespread storms. Some of the storms became severe with numerous reports of large hail, damaging winds and flash flooding.
Flash Flood · Jun 25, 2015. A frontal boundary was slowly sinking south across forecast area. Several rounds of storms developed and moved east along the front dumping up to 8 inches of rain in a 24 hour period from 7 am June 25th to 7 am June 26th. This caused considerable flash flooding, especially in Lincoln County Missouri and Calhoun County Illinois. There were also numerous reports of damaging winds and large hail.
Flash Flood · Jun 21, 2015. A cold front moved into the region and stalled out, triggering showers and thunderstorms. A number of thunderstorms developed across northern Missouri and west central Illinois. Heavy rain from the storms caused flash flooding across the region.
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 Calhoun 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.