Enter any address in Alexander County, Illinois to see its FEMA flood zone
River overflow along the Ohio and Mississippi Rivers is the dominant flood character for Alexander County. Between 2000 and 2023, NOAA Storm Events data recorded 220 flood events and 21 flash flood events in the county. For example, a prolonged flooding event on the Ohio River in early March 2025 impacted Shawneetown, Olmsted, and Cairo, with minor flooding of bottomland continuing at all three locations due to heavy rainfall in mid-February. Earlier, in May 2024, heavy rainfall caused rising river levels on the Lower Ohio, Big Muddy, and Mississippi Rivers, leading to minor flooding around Olmsted and Cairo that lasted 5 to 8 days and affected low-lying areas.
FEMA National Flood Insurance Program (NFIP) claims data indicates that properties in Zone A, which are areas with a 1% annual chance of flooding, have experienced the most claims, with an average payout of $9,910 and an average water depth of 2.4 feet. Properties in Zone X, though fewer in number, have seen significantly higher average payouts ($18,405) and water depths (8.6 feet), suggesting potential for severe damage in these areas. Residents in or near riverine floodplains, particularly those in Zone A or Zone X, should pay close attention to flood risk information.
Summary generated from NOAA storm narratives and NFIP claim data for this county. Not predictive.
83 NOAA storm reports from this county describe what happened, in the words of the meteorologists who were there.
Alexander County, Illinois has recorded 241 flood-related events since 1996 according to NOAA's Storm Events Database, including 21 flash floods and 220 river or area floods. The county has received 17 federal disaster declarations, 6 of which involved flooding or coastal storms. Enter any address above to check its FEMA flood zone designation.
FEMA Disaster Declarations (1969–2020)
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 And Flooding | Severe Storm | Apr 19, 2011 |
| Severe Winter Storm | Severe Storm | Jan 26, 2009 |
| Hurricane Katrina Evacuation | Hurricane | Aug 29, 2005 |
| Severe Storms, Tornadoes, And Flooding | Severe Storm | May 6, 2003 |
| Severe Storms, Tornadoes And Flooding | Tornado | Apr 21, 2002 |
| Severe Storms And Flooding | Severe Storm | Mar 1, 1997 |
| Severe Storms And Flooding | Severe Storm | May 15, 1995 |
NOAA Storm Events Database (1996–2025)
Source: NOAA National Weather Service Storm Events Database.
| Type | Date | Damage |
|---|---|---|
| Flood | Feb 16, 2025 | 0.00K |
| Flood | Mar 1, 2025 | 0.00K |
| Flood | Jul 18, 2024 | 0.00K |
| Flood | May 10, 2024 | 0.00K |
| Flood | May 9, 2024 | 0.00K |
| Flood | Jul 6, 2024 | 0.00K |
| Flood | Jul 5, 2024 | 0.00K |
| Flood | May 3, 2024 | 0.00K |
| Flood | May 1, 2024 | 0.00K |
| Flood | Mar 28, 2023 | 0.00K |
Flood — Feb 16, 2025
Heavy rain (3 to 7) over the lower Ohio and Tennessee Valleys on the 15th resulted in rising water levels on the Ohio River, with moderate flooding near Paducah and Olmsted, and minor flooding near Golconda, Smithland, and Cairo. Minor flooding continued into early March near Olmsted and Cairo.
Flood — Mar 1, 2025
A prolonged flooding event on the Ohio river, that began in the middle of February, continued into March at Shawneetown, Olmsted, and Cairo. Minor flooding of bottomland continued at all three locations. Heavy rainfall in the middle of February was the cause of rising river levels which lowered just below flood stage at all three sites from the afternoon of the 1st to the early morning of the 2nd.
Flood — Jul 18, 2024
Torrential rainfall in Southwest Illinois on July 16th resulted in water levels at Thebes briefly returning to minor flood, with limited impacts to low-lying agricultural areas.
Flood — May 10, 2024
Heavy rainfall in early May, culminating in the May 8th severe weather and flooding event, resulted in rising river levels on the Lower Ohio, Big Muddy, and Mississippi Rivers, with Thebes returning to minor flood and Murphysboro, Olmsted, and Cairo reaching flood stage shortly after. Minor flooding in Southern Illinois around these river sites lasted 5 to 8 days with impacts limited to low-lyi...
Flood — May 9, 2024
Heavy rainfall in early May, culminating in the May 8th severe weather and flooding event, resulted in rising river levels on the Lower Ohio, Big Muddy, and Mississippi Rivers, with Thebes returning to minor flood and Murphysboro, Olmsted, and Cairo reaching flood stage shortly after. Minor flooding in Southern Illinois around these river sites lasted 5 to 8 days with impacts limited to low-lyi...
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 Alexander 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 Alexander 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.