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Grundy County, Illinois

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

Relatively Low overall risk
37th of 102highest risk in Illinois
$50Mexpected losses a year
13federal declarations
1 in 125homes with flood insurance
Photo: U.S. Geological Survey, public domain

Grundy County, Illinois has a relatively low overall risk from natural hazards in FEMA's National Risk Index. Its risk score is higher than 66% of US counties. It ranks 37th of 102 counties in Illinois. The costliest hazards here are inland flooding, cold waves and tornadoes. FEMA estimates about $50 million a year in expected losses, or roughly $955 per resident. Since 1972 it has been included in 13 federal disaster or emergency declarations for natural events (9 major disasters). The most recent was in November 2013 (severe storms, straight-line winds and tornadoes). Fewer than 1 in 100 homes here carry federal flood insurance (161 policies). Since 1978, federal flood insurance has paid about $6.4 million on 333 claims here, including $2.1 million for floods in 2013.

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

Top risks in Grundy County

$22.2 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.
$19.9 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.

Tornado

Moderate
$4.7 million a yearExpected losses. Damaging events about once every 3 years.
  • Pick a shelter spot: a basement, or an inside room on the lowest floor with no windows.
  • Turn on emergency alerts on your phone and keep a weather radio.
HazardRatingScoreExpected loss a year
Inland floodingLow66.5
$22M
Cold waveHigh94.0
$20M
TornadoModerate68.8
$5M
Strong windModerate63.2
$2M
EarthquakeVery Low56.3
$755K
Heat waveLow45.9
$592K
LightningVery Low18.4
$122K
DroughtLow37.3
$101K
HailVery Low12.0
$76K
Winter weatherLow25.8
$47K
Ice stormVery Low24.8
$46K
WildfireVery Low15.7
$11K
HurricaneVery Low9.4
$3K
LandslideVery Low33.9
$817

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 very 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 Grundy County. 2020s bar runs to November 2026.

By type

Flood4
Snowstorm4
Severe Storm3
Hurricane1
Tornado1

Most recent

Nov 26, 2013Severe Storms, Straight-Line Winds, and TornadoesMajor disaster
May 10, 2013Severe Storms, Straight-Line Winds, and FloodingMajor disaster
Mar 17, 2011Severe Winter Storm and SnowstormMajor disaster
Oct 3, 2008Severe Storms and FloodingMajor disaster
Sep 25, 2007Severe Storms and FloodingMajor disaster
Sep 7, 2005Hurricane Katrina EvacuationEmergency
Jan 17, 2001Illinois Winter Snow StormsEmergency
Jan 8, 1999Il-Winter Storm 1/1/99Emergency
Jul 25, 1996Severe Storms and FloodingMajor disaster
Mar 29, 1985Severe Storms & FloodingMajor disaster
Show all 13
Jan 16, 1979Blizzards & SnowstormsEmergency
Jun 10, 1974Severe Storms & FloodingMajor disaster
Sep 4, 1972Severe 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 357 storm reports in Grundy County since 1958, with 0 deaths and 16 injuries and about $117 million in reported damage. The strongest on record here was an EF3 tornado on June 22, 2015 near Paytonville.

23tornadoes
77hail reports, largest 2.75 inches
197damaging thunderstorm winds
40floods and flash floods

Strongest tornadoes

DateStrengthNearHurt / killed
Jun 22, 2015EF3Paytonville7 / 0
Nov 12, 1965F2–0 / 0
Nov 17, 2013EF2Central City5 / 0
Apr 19, 1973F2–0 / 0
May 20, 1975F2–1 / 0

Most damaging storms

DateTypeNearDamage
Nov 12, 1965Tornado–$25M
Jun 22, 2015TornadoPaytonville$25M
Jul 17, 1996Flash FloodNorthern$17M
Apr 18, 2013Flash FloodNettlecreek$15M
Nov 17, 2013TornadoCentral City$11M
Sep 14, 2008Flash FloodNettlecreek$9M

Source: NOAA Storm Events Database, county-based reports through Jul 27, 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 Grundy County

Check your address flood zone ›
0.8%of homes have federal flood insurance (161 policies)
16.6%of homes in mapped high-risk flood zones are insured
$6.4 millionpaid on 333 flood claims since 1978
2013costliest year, with $2.1 million 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 Grundy County

$271,700median home value (Illinois $263,300, US $332,700)
1990median year homes were built (Illinois 1971, US 1980)
42%of homes built before 1980, before many modern wind, quake and flood building rules
3.9%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; 21,384 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
Will CountyHigh17
Kendall CountyLow11
LaSalle CountyModerate18
Kankakee CountyModerate5
Livingston CountyLow9

Common questions about Grundy County

What is the biggest natural hazard in Grundy County?

Inland flooding has the highest expected yearly losses in Grundy County, about $22.2 million a year in FEMA's estimate. Cold wave is second at $19.9 million.

How many federal disasters has Grundy County had?

Grundy County has been included in 13 federal disaster or emergency declarations for natural events since 1972, including 9 major disasters. The most recent was Severe Storms, Straight-Line Winds, and Tornadoes in November 2013.

Is Grundy County a high-risk place to live?

Its overall rating is Relatively Low, 37th 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 Grundy County?

Standard home insurance does not cover flooding. About 1 in 125 homes in Grundy 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 Grundy County had?

NOAA records list 23 tornadoes in Grundy County since 1950. The strongest was an EF3 tornado on June 22, 2015 near Paytonville. The weather service has also logged 77 hail reports and 40 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.