Cook County, Illinois
Natural disaster risk, federal disaster history and flood insurance facts.
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
- 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.
- Insulate pipes in outside walls, crawl spaces and garages.
- Know how to shut off the main water valve.
- 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.
All 18 hazards
What the ratings mean ›| Hazard | Rating | Score | Expected loss a year | |
|---|---|---|---|---|
| Inland flooding | 99.9 | $1.1B | ||
| Cold wave | 100.0 | $700M | ||
| Tornado | 100.0 | $345M | ||
| Heat wave | 99.8 | $193M | ||
| Earthquake | 98.4 | $57M | ||
| Strong wind | 99.6 | $12M | ||
| Hail | 99.1 | $11M | ||
| Winter weather | 100.0 | $4M | ||
| Lightning | 98.2 | $3M | ||
| Ice storm | 97.2 | $2M | ||
| Hurricane | 48.9 | $57K | ||
| Wildfire | 55.8 | $56K | ||
| Coastal flooding | 44.0 | $37K | ||
| Drought | 25.7 | $12K | ||
| Landslide | 56.4 | $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
Most recent
Show all 22
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.
Strongest tornadoes
| Date | Strength | Near | Hurt / killed |
|---|---|---|---|
| Apr 21, 1967 | F4 | – | 500 / 33 |
| Jun 13, 1976 | F4 | – | 23 / 2 |
| Mar 27, 1991 | F3 | – | 7 / 0 |
| Jun 20, 2021 | EF3 | Burr Ridge | 0 / 0 |
| Mar 12, 1976 | F2 | – | 41 / 2 |
Most damaging storms
| Date | Type | Near | Damage |
|---|---|---|---|
| Jul 2, 2023 | Flash Flood | Evanston | $500M |
| Jul 24, 2010 | Flash Flood | Bryn Mawr | $253M |
| Aug 17, 2025 | Flash Flood | Hegewisch | $230M |
| Jul 25, 2025 | Flash Flood | Burr Ridge | $200M |
| Aug 17, 2025 | Flash Flood | Bedford Park | $55M |
| Aug 22, 2014 | Flash Flood | Justice | $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 ›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
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 counties | Overall risk | Top hazard |
|---|---|---|
| Cook County | Inland flooding | |
| DuPage County | Inland flooding | |
| Lake County | Inland flooding | |
| Will County | Inland flooding | |
| Kane County | Inland flooding | |
| McHenry County | Inland flooding | |
| Winnebago County | Inland flooding | |
| Madison County | Inland flooding |
Neighboring counties
| County | Overall risk | Declarations |
|---|---|---|
| DuPage County | 14 | |
| Lake County | 15 | |
| Will County | 17 | |
| Kane County | 14 | |
| Lake County, IN | 22 | |
| McHenry County | 14 | |
| Porter County, IN | 14 | |
| Berrien County, MI | 10 |
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.