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Cook County, Illinois

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

Very High overall risk
1st of 102highest risk in Illinois
$2.4Bexpected losses a year
22federal declarations
1 in 200homes with flood insurance
Photo: Allen McGregor, CC BY 2.0

Cook County, Illinois has a very high overall risk from natural hazards in FEMA's National Risk Index. Its risk score is in the top 1% of US counties. It ranks 1st of 102 counties in Illinois. The costliest hazards here are inland flooding, cold waves and tornadoes. FEMA estimates about $2.4 billion a year in expected losses, or roughly $460 per resident. Since 1967 it has been included in 22 federal disaster or emergency declarations for natural events (18 major disasters). The most recent was in September 2024 (severe storms, tornadoes, straight-line winds and floodng). Fewer than 1 in 100 homes here carry federal flood insurance (6,353 policies). Since 1978, federal flood insurance has paid about $140 million on 15,260 claims here.

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

Top risks in Cook County

$1.1 billion a yearExpected losses. Damaging events about 6 times 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.

Cold wave

Very High
$700 million a yearExpected losses. Damaging events about 4 times a year.
  • Insulate pipes in outside walls, crawl spaces and garages.
  • Know how to shut off the main water valve.

Tornado

Very High
$345 million a yearExpected losses. Damaging events about once a year.
  • 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 floodingVery High99.9
$1.1B
Cold waveVery High100.0
$700M
TornadoVery High100.0
$345M
Heat waveVery High99.8
$193M
EarthquakeHigh98.4
$57M
Strong windVery High99.6
$12M
HailHigh99.1
$11M
Winter weatherVery High100.0
$4M
LightningVery High98.2
$3M
Ice stormVery High97.2
$2M
HurricaneVery Low48.9
$57K
WildfireVery Low55.8
$56K
Coastal floodingLow44.0
$37K
DroughtVery Low25.7
$12K
LandslideVery Low56.4
$2K

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 high 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 Cook County. 2020s bar runs to November 2026.

By type

Flood8
Severe Storm8
Snowstorm4
Tornado1
Hurricane1

Most recent

Sep 20, 2024Severe Storms, Tornadoes, Straight-Line Winds, and FloodngMajor disaster
Nov 20, 2023Severe Storms and FloodingMajor disaster
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
Aug 19, 2010Severe Storms and FloodingMajor 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
Show all 22
Jan 8, 1999Il-Winter Storm 1/1/99Emergency
Sep 17, 1997Severe Storms and FloodingMajor disaster
Jul 25, 1996Severe Storms and FloodingMajor disaster
Jul 9, 1993Severe Storms & FloodingMajor disaster
Aug 21, 1987Severe Storms & FloodingMajor disaster
Oct 7, 1986Severe Storms & FloodingMajor disaster
Jun 30, 1981Severe Storms, Flooding & TornadoesMajor disaster
Jan 16, 1979Blizzards & SnowstormsEmergency
Jun 18, 1976Severe Storms, Tornadoes & FloodingMajor disaster
Apr 26, 1973Severe Storms & FloodingMajor disaster
Sep 4, 1972Severe Storms & FloodingMajor disaster
Apr 25, 1967TornadoesMajor disaster

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

Storm history since 1954

Tornado risk by county ›

The National Weather Service has logged 2,934 storm reports in Cook County since 1954, with 59 deaths and 899 injuries and about $1.7 billion in reported damage. The strongest on record here was an F4 tornado on April 21, 1967.

90tornadoes
660hail reports, largest 2.75 inches
1,639damaging thunderstorm winds
427floods and flash floods

Strongest tornadoes

DateStrengthNearHurt / killed
Apr 21, 1967F4–500 / 33
Jun 13, 1976F4–23 / 2
Mar 27, 1991F3–7 / 0
Jun 20, 2021EF3Burr Ridge0 / 0
Mar 12, 1976F2–41 / 2

Most damaging storms

DateTypeNearDamage
Jul 2, 2023Flash FloodEvanston$500M
Jul 24, 2010Flash FloodBryn Mawr$253M
Aug 17, 2025Flash FloodHegewisch$230M
Jul 25, 2025Flash FloodBurr Ridge$200M
Aug 17, 2025Flash FloodBedford Park$55M
Aug 22, 2014Flash FloodJustice$50M

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 Cook County

Check your address flood zone ›
0.5%of homes have federal flood insurance (6,353 policies)
32%of homes in mapped high-risk flood zones are insured
$140 millionpaid on 15,260 flood claims since 1978
2013costliest year, with $35.7 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 Cook County

$324,500median home value (Illinois $263,300, US $332,700)
1961median year homes were built (Illinois 1971, US 1980)
73%of homes built before 1980, before many modern wind, quake and flood building rules
0.8%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; 2,276,493 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
DuPage CountyHigh14
Lake CountyHigh15
Will CountyHigh17
Kane CountyHigh14
Lake County, INHigh22
McHenry CountyModerate14
Porter County, INModerate14
Berrien County, MIModerate10

Common questions about Cook County

What is the biggest natural hazard in Cook County?

Inland flooding has the highest expected yearly losses in Cook County, about $1.1 billion a year in FEMA's estimate. Cold wave is second at $700 million.

How many federal disasters has Cook County had?

Cook County has been included in 22 federal disaster or emergency declarations for natural events since 1967, including 18 major disasters. The most recent was Severe Storms, Tornadoes, Straight-Line Winds, and Floodng in September 2024.

Is Cook County a high-risk place to live?

Its overall rating is Very High, 1st 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 Cook County?

Standard home insurance does not cover flooding. About 1 in 200 homes in Cook 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 Cook County had?

NOAA records list 90 tornadoes in Cook County since 1950. The strongest was an F4 tornado on April 21, 1967. The weather service has also logged 660 hail reports and 427 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.