Enter any address in Washington County, Illinois to see its FEMA flood zone
Flash flooding from intense rainfall events is the dominant flood character in Washington County, IL. Over the last 30 years, the NOAA Storm Events Database has recorded 14 flash flood events compared to 4 general flood events. For example, flash flooding occurred in April 2025 due to a stationary front and ample moisture, and again in July 2021 when training storms produced up to 4 inches of rain in a short period.
National Flood Insurance Program (NFIP) data indicates that properties designated as Zone A have experienced the majority of claims, with an average payout of $25,833 and an average water depth of 2.2 feet. While fewer claims have been filed in unknown zones, they still represent an average payout of $12,173 with an average water depth of 1.0 foot. Homeowners in areas designated as Zone A, or those whose flood zone is currently unknown, should pay particular attention to flood risk.
Summary generated from NOAA storm narratives and NFIP claim data for this county. Not predictive.
2 NOAA storm reports from this county describe what happened, in the words of the meteorologists who were there.
Washington County, Illinois has recorded 18 flood-related events since 1996 according to NOAA's Storm Events Database, including 14 flash floods and 4 river or area floods. The county has received 9 federal disaster declarations, 1 of which involved flooding or coastal storms. Enter any address above to check its FEMA flood zone designation.
FEMA Disaster Declarations (2002–2024)
Source: OpenFEMA Disaster Declarations Summaries.
| Declaration | Type | Date |
|---|---|---|
| Severe Storms, Tornadoes, Straight-line Winds, And Floodng | Flood | Jul 13, 2024 |
| Severe Storms And Flooding | Severe Storm | Jun 29, 2023 |
| Covid-19 | Biological | Jan 20, 2020 |
| Covid-19 Pandemic | Biological | Jan 20, 2020 |
| Severe Storms, Straight-line Winds, And Tornadoes | Tornado | Nov 17, 2013 |
| Severe Storms And Flooding | Severe Storm | Apr 19, 2011 |
| Severe Winter Storm And Snowstorm | Snowstorm | Jan 31, 2011 |
| Hurricane Katrina Evacuation | Hurricane | Aug 29, 2005 |
| Severe Storms, Tornadoes And Flooding | Tornado | Apr 21, 2002 |
NOAA Storm Events Database (1996–2025)
Source: NOAA National Weather Service Storm Events Database.
| Type | Date | Damage |
|---|---|---|
| Flood | Apr 29, 2025 | 0.00K |
| Flash Flood | Apr 4, 2025 | 0.00K |
| Flash Flood | Jul 26, 2022 | 50.00K |
| Flash Flood | Jul 16, 2021 | 0.00K |
| Flash Flood | Apr 3, 2014 | 0.00K |
| Flash Flood | Jun 21, 2011 | 0.00K |
| Flash Flood | May 8, 2009 | 0.00K |
| Flash Flood | Jun 8, 2009 | 0.00K |
| Flash Flood | Mar 31, 2008 | 0.00K |
| Flash Flood | Mar 18, 2008 | 0.00K |
Flood — Apr 29, 2025
During the afternoon of April 29th, a QLCS from Oklahoma and southern Kansas entered southwest Illinois. Although the QLCS had been decaying up to this point, it was still capable of producing severe weather. Wind damage, flooding, and hail were all reported as the complex passed from Randolph County through Marion County.
Flash Flood — Apr 4, 2025
A stationary front over southern Missouri along with ample mid-level forcing, moisture, and efficient rain processes resulted in flash flooding across portions of southwest and south central Illinois.
Flash Flood — Jul 26, 2022
During the early morning of Tuesday, July 26th, 2022, a complex of training thunderstorms set up roughly along the I-70 corridor in Missouri and I-64 corridor in Illinois. Several rounds of thunderstorms with rainfall rates exceeding 2in/hr affected this area, including the St. Louis metropolitan area, through the early hours of July 26th and into the morning commute. Upwards of 11 of rain fell...
Flash Flood — Jul 16, 2021
Training storms moved through portions of southeast Missouri and southwestern Illinois with up to 4 inches of rain in a short amount of time. There were several reports of flash flooding.
Flash Flood — Apr 3, 2014
A mesoscale convective complex developed and moved east across the forecast area. There were numerous reports of damaging winds, large hail, flash flooding and one tornado.
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 Washington 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 Washington 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.