Enter any address in Mason County, Illinois to see its FEMA flood zone
Flash flooding from thunderstorms is the primary flood hazard in Mason County. In the last 30 years, NOAA Storm Events data shows 18 flash flood events and 10 flood events. For example, a slow-moving thunderstorm caused widespread flash flooding in Rantoul in July 2020, and heavy rainfall led to flash flooding and areal flooding across central and southeast Illinois in April 2017.
NFIP claims data indicates that properties in Zone A have experienced the most claims, with an average payout of $9,118 and an average water depth of 8.9 feet. While Zone X_SHADED has had fewer claims, those that have occurred resulted in the highest average payout of $16,411 and an average water depth of 18.2 feet. Homeowners in Zone A, Zone X_SHADED, and those in areas with unknown flood zone designations should pay particular attention to flood risk.
Summary generated from NOAA storm narratives and NFIP claim data for this county. Not predictive.
9 NOAA storm reports from this county describe what happened, in the words of the meteorologists who were there.
Mason County, Illinois has recorded 28 flood-related events since 1996 according to NOAA's Storm Events Database, including 18 flash floods and 10 river or area floods. The county has received 18 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 (1968–2020)
Source: OpenFEMA Disaster Declarations Summaries.
| Declaration | Type | Date |
|---|---|---|
| Covid-19 | Biological | Jan 20, 2020 |
| Covid-19 Pandemic | Biological | Jan 20, 2020 |
| Severe Storms, Straight-line Winds, And Flooding | Flood | Apr 16, 2013 |
| Severe Winter Storm And Snowstorm | Snowstorm | Jan 31, 2011 |
| Snow | Snowstorm | Nov 30, 2006 |
| 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 |
| Winter Storm 1/1/99 | Snowstorm | Jan 1, 1999 |
| 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 |
|---|---|---|
| Flash Flood | Feb 22, 2023 | 0.00K |
| Flash Flood | Jul 9, 2020 | 0.00K |
| Flood | Apr 29, 2017 | 0.00K |
| Flash Flood | Apr 29, 2017 | 0.00K |
| Flash Flood | Aug 12, 2016 | 0.00K |
| Flash Flood | Jun 28, 2015 | 0.00K |
| Flash Flood | Jun 26, 2015 | 0.00K |
| Flash Flood | Jun 7, 2015 | 0.00K |
| Flood | Apr 18, 2013 | 5.00M |
| Flood | May 1, 2013 | 0.00K |
Flash Flood — Feb 22, 2023
A warm front draped along the I-72 corridor served as the initial focusing mechanism for convection across central Illinois on February 22nd. Midday temperatures ranged from the upper 30s north of the boundary in the Peoria area to the lower 70s along and south of I-70. An upper-level disturbance interacting with the sharp temperature gradient triggered clusters of strong to severe thundersto...
Flash Flood — Jul 9, 2020
A slow-moving isolated thunderstorm dropped 1 to 2 inches of rain in a short amount of time across northeast Champaign County during the late afternoon of July 9th, leading to widespread flash flooding in Rantoul. Meanwhile further west, a line of strong to severe thunderstorms developed along the Mississippi River ahead of an approaching cold front. These storms pushed into the Illinois Rive...
Flood — Apr 29, 2017
Heavy rainfall impacted central and southeast Illinois from April 29th into April 30th...creating flash flooding, which led to widespread areal flooding. Periods of thunderstorms with very high rainfall rates dropped 2.00 to 6.50 inches of rain across much of central and southeast Illinois from April 29th into early on May 1st. This rainfall, occurring on top of already saturated soils, created...
Flash Flood — Apr 29, 2017
Low pressure tracking along a stationary frontal boundary near the I-70 corridor brought widespread strong to severe thunderstorms to much of central and southeast Illinois during the late afternoon and evening of April 29th. A tornado briefly touched down in an open field northeast of Alexander in Morgan County. Elsewhere, thunderstorms packed winds of 60-70mph and caused significant wind da...
Flash Flood — Aug 12, 2016
An approaching cold front triggered thunderstorms across central Illinois during the late afternoon and evening of August 12th. Due to copious amounts of moisture in the atmosphere and the slow-moving nature of the storms, extremely heavy rain fell along and just west of I-55. The heaviest rain occurred in a swath from southern Woodford County southward into western Sangamon County where 3.00...
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 Mason 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 Mason 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.