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Warren County, Illinois

Natural disaster risk, federal disaster history and flood insurance facts.

Very Low overall risk
92nd of 102highest risk in Illinois
$7Mexpected losses a year
7federal declarations
1 in 250homes with flood insurance
Photo: U.S. Geological Survey, public domain

Warren County, Illinois has a very low overall risk from natural hazards in FEMA's National Risk Index. Its risk score is lower than 84% of US counties. It ranks 92nd of 102 counties in Illinois. The costliest hazards here are inland flooding, cold waves and drought. FEMA estimates about $7.0 million a year in expected losses, or roughly $417 per resident. Since 1993 it has been included in 7 federal disaster or emergency declarations for natural events (5 major disasters). The most recent was in August 2023 (severe storms and flooding). Only 26 homes here carry federal flood insurance. Since 1978, federal flood insurance has paid about $193,000 on 26 claims here.

FEMA National Risk Index December 2025; OpenFEMA declarations to Nov 6, 2026; NFIP records. Updated November 6, 2026.

Top risks in Warren County

$1.7 million a yearExpected losses. Damaging events about once a year.
  • Check the FEMA flood map for your address, and ask the seller or landlord about past flooding.
  • Price a flood policy now. Most new federal policies take 30 days to start.
$1.2 million a yearExpected losses. Damaging events about 5 times a year.
  • Insulate pipes in outside walls, crawl spaces and garages.
  • Know how to shut off the main water valve.

Drought

Moderate
$1.2 million a yearExpected losses. Damaging events about 9 times a year.
  • Check local water restrictions.
  • Choose drought-tolerant plants.
HazardRatingScoreExpected loss a year
Inland floodingVery Low11.0
$2M
Cold waveLow53.5
$1M
DroughtModerate81.9
$1M
Heat waveLow65.8
$864K
Strong windLow46.1
$564K
TornadoLow28.5
$529K
HailLow65.4
$526K
LightningLow36.7
$164K
Ice stormLow55.0
$123K
EarthquakeVery Low34.4
$122K
Winter weatherLow32.9
$39K
HurricaneVery Low17.5
$6K
LandslideVery Low49.8
$2K
WildfireVery Low0.2
$91

Scores are percentiles: a score of 90 means higher risk than about 90% of US counties for that hazard. Hazards FEMA does not rate here are left out. Social vulnerability is relatively low and community resilience is very high in FEMA's measures.

Federal disaster history

Recent disasters nationwide ›

Declarations by decade

Federal declarations for natural events that included Warren County. 2020s bar runs to November 2026.

By type

Flood2
Snowstorm2
Severe Storm2
Hurricane1

Most recent

Aug 15, 2023Severe Storms and FloodingMajor disaster
May 10, 2013Severe Storms, Straight-Line Winds, and FloodingMajor disaster
Mar 17, 2011Severe Winter Storm and SnowstormMajor disaster
Sep 25, 2007Severe Storms and FloodingMajor disaster
Sep 7, 2005Hurricane Katrina EvacuationEmergency
Jan 8, 1999Il-Winter Storm 1/1/99Emergency
Jul 9, 1993Severe Storms & FloodingMajor disaster

Illinois also had 2 statewide declarations that did not name single counties.

Storm history since 1958

Tornado risk by county ›

The National Weather Service has logged 306 storm reports in Warren County since 1958, with 1 death and 1 injury and about $7.7 million in reported damage. The strongest on record here was an F2 tornado on September 26, 1959.

36tornadoes
75hail reports, largest 1.75 inches
166damaging thunderstorm winds
26floods and flash floods

Strongest tornadoes

DateStrengthNearHurt / killed
Sep 26, 1959F2–0 / 1
Jul 16, 2015EF2Nemo1 / 0
Jul 16, 2015EF2Kirkwood0 / 0
Apr 18, 1963F2–0 / 0
Apr 5, 1999F2Swan Creek0 / 0

Most damaging storms

DateTypeNearDamage
May 8, 2003HailMonmouth$2M
Jul 16, 2015TornadoNemo$2M
May 4, 2003Flash FloodMonmouth$1M
Sep 11, 2000Thunderstorm WindMonmouth$500K
May 10, 2003HailCountywide$500K
May 10, 2003TornadoYoungstown$300K

Source: NOAA Storm Events Database, county-based reports through Jul 20, 2026. Tornado records start in 1950, hail and wind in 1955, and floods and other storm types in 1996, so older decades undercount. Damage is in dollars of the year it happened and is often an estimate. Winter storms, heat and hurricanes are logged by forecast zone, not county, so they are not counted here.

Flood insurance in Warren County

Check your address flood zone ›
0.4%of homes have federal flood insurance (26 policies)
0%of homes in mapped high-risk flood zones are insured
$193,253paid on 26 flood claims since 1978
2008costliest year, with $73,661 paid

National Flood Insurance Program (NFIP) records only; private flood policies are not included. Home counts as of Aug 3, 2026. Since 2021 NFIP prices each home separately under Risk Rating 2.0, so your price depends on the building, not the county. Ask an agent for a quote.

Homes in Warren County

$105,000median home value (Illinois $263,300, US $332,700)
1956median year homes were built (Illinois 1971, US 1980)
84%of homes built before 1980, before many modern wind, quake and flood building rules
2.6%of homes are mobile homes, which are the least safe in tornadoes and high winds

Older homes and mobile homes usually suffer more damage in storms, floods and earthquakes, and can cost more to insure. If you are buying, ask about roof age, foundation bolting and any retrofits. Source: US Census Bureau, American Community Survey 2020 to 2024 5-year estimates; 7,587 housing units.

Compare in Illinois

All 102 ›
Largest countiesOverall riskTop hazard
Cook CountyVery HighInland flooding
DuPage CountyHighInland flooding
Lake CountyHighInland flooding
Will CountyHighInland flooding
Kane CountyHighInland flooding
McHenry CountyModerateInland flooding
Winnebago CountyModerateInland flooding
Madison CountyModerateInland flooding

Neighboring counties

CountyOverall riskDeclarations
Knox CountyLow9
Fulton CountyLow18
McDonough CountyVery Low9
Mercer CountyVery Low13
Henderson CountyVery Low14

Common questions about Warren County

What is the biggest natural hazard in Warren County?

Inland flooding has the highest expected yearly losses in Warren County, about $1.7 million a year in FEMA's estimate. Cold wave is second at $1.2 million.

How many federal disasters has Warren County had?

Warren County has been included in 7 federal disaster or emergency declarations for natural events since 1993, including 5 major disasters. The most recent was Severe Storms and Flooding in August 2023.

Is Warren County a high-risk place to live?

Its overall rating is Very Low, 92nd highest of 102 in Illinois. A county rating covers the whole area. Risk at one address can be much higher or lower, so check the FEMA flood map and ask about the home's history.

Do I need flood insurance in Warren County?

Standard home insurance does not cover flooding. About 1 in 250 homes in Warren County has federal flood insurance. Lenders require it in mapped high-risk zones, but many flood claims come from outside those zones.

How many tornadoes has Warren County had?

NOAA records list 36 tornadoes in Warren County since 1950. The strongest was an F2 tornado on September 26, 1959. The weather service has also logged 75 hail reports and 26 floods here.

Sources: FEMA National Risk Index (December 2025), OpenFEMA Disaster Declarations Summaries, and NFIP policy and claims data. Hazard Compass is independent and not affiliated with FEMA. These figures describe the whole county, not a single property, and are not insurance or safety advice. Report a problem.