riskbycounty
FEMA NRI 1.19.0Updated Nov 2023 · Coverage 2014–2023Methodology

Cook County Disaster Risk

Cook County, Illinois

FEMA Risk Rating

Very High

National Percentile

100th

of 3,144 counties

State Rank

#1

of 102 (1 = highest risk)

Flood Risk

100th

percentile

Hazard Risk Breakdown

Flood

River, coastal, and surface flooding risk

Very High

Higher than 100% of US counties

Wildfire

Wildland and wildland-urban interface fire risk

Relatively Low

Higher than 56% of US counties

Tornado

Tornado and severe thunderstorm risk

Very High

Higher than 100% of US counties

Earthquake

Seismic activity and ground shaking risk

Relatively High

Higher than 98% of US counties

Hurricane

Tropical cyclone and hurricane risk

Relatively Low

Higher than 49% of US counties

Risk Overview

About Natural Disaster Risk in Cook County, Illinois

Cook County faces very high risk

Cook County's composite risk score of 99.97 ranks among the highest in the nation, earning a Very High risk designation. This score reflects substantial and widespread exposure to multiple major natural hazards.

Illinois's riskiest county by far

At 99.97, Cook County dramatically exceeds Illinois's state average of 54.46 and ranks as the state's highest-risk region. Residents face nearly double the disaster exposure of the typical Illinois county.

Vastly riskier than all neighbors

Cook County (99.97) faces substantially higher disaster risk than all surrounding counties, including Cass County (38.65) and Christian County (54.04). Its risk profile stands alone as the state's most hazardous region.

Tornadoes and floods dominate

Cook County's tornado risk (99.97) and flood risk (99.94) both rank among the nation's highest, nearly maxing out the scale. These catastrophic-level exposures, combined with significant earthquake (98.41) and wildfire (55.79) risks, create an exceptionally complex hazard environment.

Comprehensive coverage is non-negotiable

Cook County residents must obtain flood insurance, secure robust tornado coverage, and review earthquake protection as part of a comprehensive insurance strategy. Advanced emergency planning, safe room construction, and regular policy updates are essential safeguards in this very high-risk region.

Source: FEMA National Risk Index · Narrative reviewed by Evan Brooks, Data Editor

Preparedness Guide

What to Prepare for in Cook County

Top Hazards by Exposure

  1. #1
    TornadoPrepare
    100th percentile
  2. #2
    FloodPrepare
    100th percentile
  3. #3
    EarthquakePrepare
    98th percentile

Source: FEMA National Risk Index v1.19.0 · Percentiles are national (3,144 counties)

Local Resources

Risk Advisory: Cook County

Risk Verdict

Cook County is among the most disaster-exposed counties in the United States, scoring at the 100th percentile under FEMA's National Risk Index. This risk level calls for more than general awareness: insurance coverage review, a family communication plan, and a prepared go-bag are practical priorities.

Hazard Breakdown

Tornado risk is Cook County's dominant natural hazard, ranked at the 100th percentile nationally under FEMA's National Risk Index. Flood ranks second at the 100th percentile nationally. Additional tracked hazards include earthquake (98th percentile), wildfire (56th percentile), hurricane (49th percentile).

Preparedness Context

Tornado risk is Cook County's top-ranked natural hazard at the 100th percentile nationally. For Cook County households, the most protective action available is identifying a reinforced interior room on the lowest floor — a bathroom, closet, or central hallway away from windows. The secondary flood hazard at the 100th percentile nationally adds seasonal complexity to Cook County's preparedness calendar, since flood and tornado risk often peak at different points in the year. A battery-powered NOAA All Hazards weather radio with an auto-alert tone is the highest-leverage single item for tornado preparedness in Cook County, since it delivers warnings even when power is out and phone networks are congested.

Regional Context

Cook County's composite risk score sits 45.5 points above the Illinois county average, placing it among the more hazard-exposed counties in the state.

Is your household prepared for Cook County's hazards?

Review FEMA's county-specific preparedness checklists and emergency planning guides.

FEMA Ready Guide →

Frequently Asked Questions

What is the natural disaster risk in Cook County, IL?
Cook County has a FEMA National Risk Index rating of Very High, placing it in the 100th percentile nationally out of 3,144 counties. This composite score reflects the county's overall exposure to natural hazards including floods, wildfires, tornadoes, earthquakes, and hurricanes, weighted by expected annual loss and social vulnerability.
What types of natural hazards affect Cook County?
Cook County is evaluated for five major natural hazard types: tornado (100th percentile), flooding (100th percentile), earthquake (98th percentile), wildfire (56th percentile), hurricane (49th percentile). The highest-risk hazard is tornado at the 100th percentile nationally. These scores are derived from FEMA's National Risk Index, which analyzes expected annual loss, social vulnerability, and community resilience for each hazard type.
How does Cook County risk compare to the Illinois average?
Cook County's composite risk percentile is 100th, compared to the Illinois state average of 55th percentile. The state's overall risk rating is Relatively Low. This means Cook County faces higher natural disaster risk than the typical county in Illinois.
Is Cook County at risk for tornado?
Yes, Cook County's tornado risk is at the 100th percentile nationally. This places it in the top quartile for this hazard type. For flooding specifically, Cook County is at the 100th percentile.
How is natural disaster risk measured?
FEMA's National Risk Index (NRI) calculates risk scores for 18 natural hazard types across all U.S. counties and census tracts. The composite score combines Expected Annual Loss (estimated dollar losses from each hazard), Social Vulnerability (demographic factors affecting disaster impact), and Community Resilience (ability to recover). Percentile scores rank each county against all 3,144 U.S. counties, and risk ratings range from Very Low to Very High.
Why is Cook County higher risk than average?
Cook County's composite risk score of 100th percentile is above the Illinois state average of 55th percentile. This elevated risk is driven by tornado exposure (100th percentile), along with flooding and earthquake and wildfire risk. Geographic location, terrain, climate patterns, and proximity to flood zones or fault lines all influence a county's risk profile.

Counties with Similar Risk

DuPage County

Illinois

-2.3

Relatively High

98th percentile

Will County

Illinois

-2.7

Relatively High

97th percentile

Lake County

Illinois

-4.0

Relatively High

96th percentile

By Evan Brooks, Data EditorUpdated Reviewed by Evan Brooks, Data Editor

Data Source

Risk data sourced from the FEMA National Risk Index (NRI). Risk scores are relative rankings (0–100) across all US counties — not absolute risk measures. Higher scores indicate higher relative risk compared to other counties.

Disclaimer: This data is informational only. It is not financial, insurance, or legal advice. Always consult a qualified professional before making insurance or real estate decisions.

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