404 flood insurance claims·$4.5M paid·3 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 DeKalb 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 DeKalb County, accounting for 27 of the 46 recorded flood events in the NOAA Storm Events Database over the last 30 years alongside 19 general flood events. Torrential rainfall from storms can cause significant damage, such as the rounds of thunderstorms on August 18, 2025, that produced flash flooding and damaging winds in the county, as well as the heavy rain and isolated flooding from scattered thunderstorms on July 14, 2024.
National Flood Insurance Program records indicate that flood risks affect properties across multiple zones. Zone A bears the highest burden with 258 claims, an average payout of $15,307, and an average recorded water depth of 9 inches. Properties located in Zone X experience fewer claims overall, but recorded higher severity in some instances, averaging 26 inches of water depth across 29 claims with an average payout of $19,342. Zone UNKNOWN, Zone X_UNSHADED, and Zone X_SHADED account for a combined 117 claims with average water depths ranging from 3 to 8 inches.
Homeowners, real estate agents, and journalists should pay the closest attention to properties situated within Zone A, which has the highest concentration of historical claims, as well as homes located in Zone X where individual flood events have resulted in significantly deeper average water depths.
Summary written from NOAA storm reports and NFIP claims for this county. Not a prediction.
18% of DeKalb County’s flood insurance claims were on properties rated outside FEMA’s high-risk zones.
316 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 9 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 1996, with 89 claims and $1.1M paid, the year of Severe Storms and 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.
12 NOAA storm reports from DeKalb County describe what happened, in the words of the forecasters who covered it. Read the Illinois flood stories →
12 federal disaster declarations since 1973, 3 of them floods, coastal storms or hurricanes.
| Disaster | Began |
|---|---|
| Severe Storms, Straight-line Winds, And Flooding | Apr 16, 2013 |
| Severe Winter Storm And Snowstorm | Jan 31, 2011 |
| Severe Storms And Flooding | Sep 13, 2008 |
| Severe Storms And Flooding | Aug 20, 2007 |
| Snow | Nov 30, 2006 |
| Hurricane Katrina Evacuation | Aug 29, 2005 |
| Severe Storms And Flooding | Jul 17, 1996 |
| Blizzards & Snowstorms | Jan 16, 1979 |
Weather and water disasters only; most recent first. Source: OpenFEMA Disaster Declarations.
46 since 1996: 27 flash floods and 19 river or area floods.
| Event | Date | Damage |
|---|---|---|
| Flash Flood | Aug 18, 2025 | — |
| Flood | Jul 14, 2024 | — |
| Flood | Aug 28, 2022 | — |
| Flash Flood | Aug 8, 2022 | — |
| Flood | Jul 6, 2022 | — |
| Flash Flood | May 23, 2020 | — |
| Flash Flood | May 14, 2020 | — |
| Flood | Jul 19, 2017 | — |
— = no damage estimate in the record. Source: NOAA Storm Events Database.
Flash Flood · Aug 18, 2025. During the afternoon and evening of the 18th, a few rounds of thunderstorms brought torrential rainfall to much of northern Illinois resulting in flash flooding. One particularly strong storm also produced damaging winds in DeKalb County. Initial reports estimate $8.8 million in flood damages around northern and northeast Illinois, and around $2.5 million in the city of Chicago alone.
Flood · Jul 14, 2024. Scattered thunderstorms moved across northern Illinois during the morning of July 14th producing isolated wind damage, heavy rain and isolated flooding. Numerous locations reported thunderstorm wind gusts between 40 and 50 mph.
Flood · Aug 28, 2022. Scattered thunderstorms moved across northern Illinois during the afternoon and early evening of August 28th producing scattered wind damage.
Flash Flood · Aug 8, 2022. Heavy rain caused flash flooding across parts of northwest Illinois during the morning of August 8th when rainfall of 3 to 5 inches with locally higher amounts fell. Previous rainfall the day before brought two day rainfall totals to 6 to 9 inches across many areas across northwest Illinois. A church was struck by lightning in Rockford during the morning of August 8th causing significant damage. Rockford Airpor…
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 DeKalb 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.