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Knox County, Illinois

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

Relatively Low overall risk
48th of 102highest risk in Illinois
$18Mexpected losses a year
9federal declarations
1 in 1000homes with flood insurance
Photo: U.S. Geological Survey, public domain

Knox County, Illinois has a relatively low overall risk from natural hazards in FEMA's National Risk Index. Its risk score is higher than 57% of US counties. It ranks 48th of 102 counties in Illinois. The costliest hazards here are inland flooding, strong wind and cold waves. FEMA estimates about $18 million a year in expected losses, or roughly $360 per resident. Since 1974 it has been included in 9 federal disaster or emergency declarations for natural events (6 major disasters). The most recent was in September 2019 (severe storms and flooding). Only 29 homes here carry federal flood insurance. Since 1978, federal flood insurance has paid about $392,000 on 40 claims here.

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

Top risks in Knox County

$6 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.
$3.1 million a yearExpected losses. Damaging events about 6 times a year.
  • Secure outdoor furniture and trash bins before storms.
  • Have trees near the house checked.

Cold wave

Moderate
$2.5 million a yearExpected losses. Damaging events about 6 times a year.
  • Insulate pipes in outside walls, crawl spaces and garages.
  • Know how to shut off the main water valve.
HazardRatingScoreExpected loss a year
Inland floodingLow49.4
$6M
Strong windHigh96.0
$3M
Cold waveModerate75.4
$3M
TornadoModerate67.8
$2M
Heat waveModerate80.3
$1M
HailModerate83.8
$1M
DroughtModerate74.3
$623K
LightningModerate66.4
$401K
EarthquakeVery Low58.4
$388K
Ice stormModerate71.0
$215K
Winter weatherLow56.0
$74K
HurricaneVery Low22.1
$7K
LandslideLow70.8
$6K
WildfireVery Low1.1
$446

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 moderate and community resilience is relatively high in FEMA's measures.

Federal disaster history

Recent disasters nationwide ›

Declarations by decade

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

By type

Flood4
Snowstorm3
Hurricane1
Severe Storm1

Most recent

Sep 19, 2019Severe 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
Dec 29, 2006SnowEmergency
Sep 7, 2005Hurricane Katrina EvacuationEmergency
Jan 8, 1999Il-Winter Storm 1/1/99Emergency
Jul 9, 1993Severe Storms & FloodingMajor disaster
Jun 10, 1974Severe Storms & FloodingMajor disaster

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

Storm history since 1961

Tornado risk by county ›

The National Weather Service has logged 398 storm reports in Knox County since 1961, with 2 deaths and 48 injuries and about $54.5 million in reported damage. The strongest on record here was an F3 tornado on May 14, 1961.

31tornadoes
114hail reports, largest 4.5 inches
208damaging thunderstorm winds
44floods and flash floods

Strongest tornadoes

DateStrengthNearHurt / killed
May 14, 1961F3–8 / 0
Jun 14, 1974F3–1 / 0
May 13, 1995F2St Augustine2 / 0
Jun 5, 2010EF2Douglas0 / 0
Mar 23, 1975F2–2 / 0

Most damaging storms

DateTypeNearDamage
Apr 18, 2013Flash FloodYates City$40M
May 14, 1961Tornado–$3M
Jun 29, 1998TornadoWilliamsfield$2M
May 13, 1995TornadoSt Augustine$2M
May 16, 2009FloodSt Augustine$2M
Aug 23, 2007Thunderstorm WindGalesburg Arpt$1M

Source: NOAA Storm Events Database, county-based reports through Jun 17, 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 Knox County

Check your address flood zone ›
0.1%of homes have federal flood insurance (29 policies)
11.4%of homes in mapped high-risk flood zones are insured
$392,051paid on 40 flood claims since 1978
2013costliest year, with $165,522 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 Knox County

$111,900median home value (Illinois $263,300, US $332,700)
1957median year homes were built (Illinois 1971, US 1980)
81%of homes built before 1980, before many modern wind, quake and flood building rules
3.8%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; 23,758 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
Peoria CountyModerate13
Henry CountyLow14
Fulton CountyLow18
Warren CountyVery Low7
Mercer CountyVery Low13
Stark CountyVery Low6

Cities in Knox County

Common questions about Knox County

What is the biggest natural hazard in Knox County?

Inland flooding has the highest expected yearly losses in Knox County, about $6 million a year in FEMA's estimate. Strong wind is second at $3.1 million.

How many federal disasters has Knox County had?

Knox County has been included in 9 federal disaster or emergency declarations for natural events since 1974, including 6 major disasters. The most recent was Severe Storms and Flooding in September 2019.

Is Knox County a high-risk place to live?

Its overall rating is Relatively Low, 48th 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 Knox County?

Standard home insurance does not cover flooding. About 1 in 1000 homes in Knox 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 Knox County had?

NOAA records list 31 tornadoes in Knox County since 1950. The strongest was an F3 tornado on May 14, 1961. The weather service has also logged 114 hail reports and 44 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.