Enter any address in Mercer County, Illinois to see its FEMA flood zone
River overflow along the Mississippi River is a significant flood concern in Mercer County. Over the past 30 years, NOAA Storm Events data shows 42 flood events and 13 flash flood events. For instance, in April 2023, significant flooding occurred on the Mississippi River due to snowmelt and saturated soils, impacting numerous homes and businesses. Earlier, in July 2024, prolonged rainfall across Minnesota and Wisconsin contributed to rises on the Mississippi River along the Iowa and Illinois border, delaying its fall below flood stage.
National Flood Insurance Program (NFIP) claims data indicates that properties in Zone A experienced the most claims, with an average payout of $26,301 and an average water depth of 10.0 feet. Properties in Zone X also saw claims, with an average payout of $27,427 and an average water depth of 22.0 feet, though fewer claims were recorded in this zone. Homeowners in Zone A, Zone X, and those located near the Mississippi River should pay particular attention to flood risk.
Summary generated from NOAA storm narratives and NFIP claim data for this county. Not predictive.
19 NOAA storm reports from this county describe what happened, in the words of the meteorologists who were there.
Mercer County, Illinois has recorded 55 flood-related events since 1996 according to NOAA's Storm Events Database, including 13 flash floods and 42 river or area floods. The county has received 15 federal disaster declarations, 7 of which involved flooding or coastal storms. Enter any address above to check its FEMA flood zone designation.
FEMA Disaster Declarations (1965–2020)
Source: OpenFEMA Disaster Declarations Summaries.
| Declaration | Type | Date |
|---|---|---|
| Covid-19 | Biological | Jan 20, 2020 |
| Covid-19 Pandemic | Biological | Jan 20, 2020 |
| Severe Storms And Flooding | Flood | Feb 24, 2019 |
| Severe Storms, Straight-line Winds, And Flooding | Flood | Apr 16, 2013 |
| Severe Winter Storm And Snowstorm | Snowstorm | Jan 31, 2011 |
| Severe Storms And Flooding | Severe Storm | Jun 1, 2008 |
| Hurricane Katrina Evacuation | Hurricane | Aug 29, 2005 |
| Flooding | Flood | Apr 18, 2001 |
| Winter Storm 1/1/99 | Snowstorm | Jan 1, 1999 |
| Severe Storms & Flooding | Flood | Apr 13, 1993 |
NOAA Storm Events Database (1996–2025)
Source: NOAA National Weather Service Storm Events Database.
| Type | Date | Damage |
|---|---|---|
| Flash Flood | Jul 11, 2025 | 0.00K |
| Flood | Jul 2, 2024 | 0.00K |
| Flood | Apr 26, 2023 | 0.00K |
| Flash Flood | Aug 31, 2021 | 0.00K |
| Flood | Apr 26, 2019 | 0.00K |
| Flood | May 21, 2019 | 0.00K |
| Flood | May 20, 2019 | 0.00K |
| Flood | Mar 16, 2019 | 0.00K |
| Flood | Oct 13, 2019 | 0.00K |
| Flood | May 1, 2019 | 0.00K |
Flash Flood — Jul 11, 2025
On July 11th, a line of severe thunderstorms moved across eastern Iowa and into northwest Illinois. These storms produced damaging straight-line winds and very heavy rain. Rainfall totals of 2 to 4 inches fell in a few hours across the Quad Cities, on top of heavy rain from the previous night and caused flash flooding in Moline and Bureau County. A Considerable Flash Flood warning was issued a...
Flood — Jul 2, 2024
Rain that fell during the month of June across Minnesota and Wisconsin caused rises on the Mississippi River, along the Iowa and Illinois border. Additionally, heavy rain that fell locally in July helped to prolong the crest and delay the river falling below flood stage, especially south of the Wapsipinicon, Rock, and Iowa Rivers.
Flood — Apr 26, 2023
Significant flooding occurred on the mainstem Mississippi largely due to the record snowfall this winter in Minnesota and Wisconsin, frozen ground, rapid snowmelt during the middle of April, and saturated soils. Major flooding was observed at all sites along the Mississippi north of Keokuk Iowa and most sites saw one of their top 10 crests on record.|This flooding had numerous impacts, with ma...
Flash Flood — Aug 31, 2021
A cluster of slow moving storms formed the afternoon of August 31st in northwest Illinois. These dropped 1 to 4 1/2 inches of rain in a short period of time.
Flood — Apr 26, 2019
The Mississippi River remained high through the month of April due to a combination of snow melt and several rounds of heavy rain. Rain in the second half of the month caused the Mississippi River to rise back above major flood stage during the last week of April. The major flooding would continue into May.
Source: NOAA National Weather Service Storm Events Database.
Source: OpenFEMA NFIP Individual Claims (2.25M records analyzed).
FEMA assigns flood zone designations to areas in Mercer 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.
Properties in Mercer 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.