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Natural hazard risk in Cook County, Illinois

Updated October 30, 2026. Based on FEMA, NOAA and OpenFEMA data. Published by Humblebee.

FEMA overall Risk Index rating: Very High (score 99.9 of 100)[5]

Expected annual loss (FEMA)
$2.42 billion[1]
Federal disaster declarations since 1967
22[2]
NFIP flood claims paid, 1978 to 2026
$139.8 million[3]
Tornadoes recorded, 1950 to 2024
86[4]

FEMA's National Risk Index (version 1.20, December 2025) rates overall natural hazard risk in Cook County, Illinois, as Very High compared with other US counties, with a score of 99.9 out of 100[5]. Within the county, the hazards with the highest FEMA scores are cold wave, winter weather and tornado[6].

FEMA risk ratings for each hazard

Ratings and expected losses from the FEMA National Risk Index. Each rating compares this county with all US counties for that hazard, from Very Low to Very High. They are planning estimates, not predictions, and they do not describe any single property.

FEMA's National Risk Index estimates Expected Annual Loss from all 18 natural hazards in Cook County at $2.42 billion a year[1]. This is an estimate of average yearly loss, not money anyone paid, and it does not predict next year's losses[7]. Inland flooding accounts for $1.10 billion a year[8], cold wave for $700.0 million[9] and tornado for $344.7 million[10]. FEMA rates social vulnerability Relatively High (score 61.7), which describes how susceptible social groups are to harm from hazards[11]. FEMA rates community resilience Relatively High (score 73.2), which describes the ability to prepare for, withstand and recover from hazards[12].

Hazards sorted by FEMA hazard-type Risk Index score, highest first
HazardFEMA risk ratingExpected annual loss
Cold WaveVery High$700.0 million[9]
Winter WeatherVery High$4.4 million[13]
TornadoVery High$344.7 million[10]
Inland FloodingVery High$1.10 billion[8]
Heat WaveVery High$193.4 million[14]
Strong WindVery High$11.6 million[15]
HailRelatively High$11.1 million[16]
EarthquakeRelatively High$57.3 million[17]
LightningVery High$2.7 million[18]
Ice StormVery High$2.0 million[19]
LandslideVery Low$1,810[20]
WildfireVery Low$56,000[21]
HurricaneVery Low$57,000[22]
Coastal FloodingRelatively Low$37,000[23]
DroughtVery Low$12,000[24]

Rated Not Applicable by FEMA for this county: avalanche, volcanic activity[25].

Social vulnerability and community resilience

FEMA uses these two ratings to scale expected losses into the Risk Index.

FEMA measureRatingScore
Social vulnerabilityRelatively High61.7[11]
Community resilienceRelatively High73.2[12]

Flooding and flood insurance

FEMA rates inland flooding risk in Cook County Very High (score 99.9 of 100)[8]. FEMA rates coastal flooding risk Relatively Low (score 44.0)[23]. OpenFEMA data as of 2026-08-03 show 6,353 residential flood insurance contracts in force out of 1,241,949 residential structures, a penetration rate of 0.5%[26]. A HazardFacts tally of OpenFEMA records counts 15,260 NFIP claims for losses from 1978 to 2026, and NFIP paid $139.8 million in total[3]. The years with the most paid claims were 2008, 2013 and 2010[3].

Measure Value
Inland Flooding, FEMA risk rating[8] Very High, $1.10 billion expected loss a year
Coastal Flooding, FEMA risk rating[23] Relatively Low, $37,000 expected loss a year
NFIP residential flood policies in force (2026)[26] 6,353 of 1,241,949 homes
Homes in FEMA's mapped high-risk flood area (SFHA)[26] 12,558, of which 4,016 insured
NFIP flood claims, 1978 to 2026[3] 15,260 filed, $139.8 million paid

Is a specific address in a flood zone? Only FEMA's flood maps answer that, property by property[27]. This page describes the whole county.

Search an address on the FEMA Flood Map Service Center

Disaster declarations and tornado records

OpenFEMA lists 22 federal disaster declarations for natural hazards that include Cook County since 1967, including 8 for floods and 8 for severe storms[2]. The most recent was DR-4819-IL, declared 2024-09-20[28]. NOAA's Storm Prediction Center tornado database records 86 tornadoes that touched Cook County from 1950 to 2024[4]. The strongest were rated F4, and the most recent recorded tornado was on 2024-07-15[4].

Federal disaster declarations for natural hazards that include Cook County, since 1967
Incident type Declarations
Flood[2] 8
Severe Storm[2] 8
Snowstorm[2] 4
Tornado[2] 1
Hurricane[2] 1
Most recent declarations
Declaration Incident Declared
DR-4819-IL[28] Severe Storms, Tornadoes, Straight-Line Winds, And Floodng 2024-09-20
DR-4749-IL[28] Severe Storms And Flooding 2023-11-20
DR-4728-IL[28] Severe Storms And Flooding 2023-08-15
DR-4116-IL[28] Severe Storms, Straight-Line Winds, And Flooding 2013-05-10
DR-1960-IL[28] Severe Winter Storm And Snowstorm 2011-03-17

How to prepare

Steps from Ready.gov, FEMA's preparedness site, for the hazards with the highest FEMA ratings here. Follow instructions from local officials and the National Weather Service when a warning is issued.

Winter storms and cold

Before

  • Insulate your home and learn how to keep pipes from freezing.
  • Install and test smoke and carbon monoxide detectors with battery backup.
  • Keep several days of supplies in case the power goes out, including medication and pet needs.
  • Put an emergency kit in your car with jumper cables, sand, blankets, water and snacks, and keep the tank full.

During

  • Under a winter storm warning, find shelter right away.
  • Stay off the roads if you can. If you are stuck in your car, stay inside it.
  • Run generators and grills only outdoors, away from windows, and never heat your home with an oven or stove.

Source: Ready.gov, winter storms and cold

Tornadoes

Before

  • Learn the warning signs: a rotating funnel cloud, an approaching cloud of debris or a loud roar like a freight train.
  • Sign up for community warning systems and learn what your local sirens sound like.
  • Pick a safe spot, such as a safe room built to FEMA criteria or an ICC 500 storm shelter, and practice getting there.
  • Include your pets in the household emergency plan.
  • Keep supplies, food, water and medication in case you have to stay home for a long time.

During

  • Go right away to the safe place you picked in advance.
  • Protect your head and neck with your arms and stay away from windows, doors and outside walls.
  • No place in a car is fully safe. If you can get lower than the road, leave the car and lie down there.

Source: Ready.gov, tornadoes

Floods

Before

  • Check your flood risk with FEMA's Flood Map Service Center, and remember that floods do not follow map lines.
  • Sign up for your community's warning system. NOAA Weather Radio also broadcasts alerts.
  • Buy flood insurance through the NFIP well before a disaster. Homeowners policies do not cover flooding, and a new policy typically takes up to 30 days to go into effect.
  • Make a household plan with evacuation routes, shelter locations and what to do in a flash flood.
  • Keep important documents in a waterproof container and make password-protected digital copies.

During

  • If you are told to evacuate, leave right away and never drive around barricades.
  • Do not walk, swim or drive through floodwater. Six inches of moving water can knock you down.
  • If you are trapped in a building, go to the highest level, but do not climb into a closed attic.

Source: Ready.gov, floods

Questions people ask

Is Cook County at risk of flooding?
FEMA rates inland flooding risk in Cook County Very High compared with other US counties, with a score of 99.9 of 100[8]. NFIP paid $139.8 million for flood claims in the county for losses from 1978 to 2026[3].
Does Cook County get tornadoes?
NOAA's Storm Prediction Center tornado database records 86 tornadoes that touched Cook County from 1950 to 2024[4]. FEMA rates tornado risk Very High compared with other US counties (score 99.9)[10].
Is Cook County at risk of earthquakes?
FEMA rates earthquake risk in Cook County Relatively High compared with other US counties, with a score of 98.4 of 100[17]. FEMA's modeled annual frequency is 0.0013 events per year[17].
How many federal disasters have been declared in Cook County?
OpenFEMA lists 22 federal disaster declarations for natural hazards that include Cook County since 1967[2]. The most recent, DR-4819-IL, was declared 2024-09-20[28].
How do I check if a home in Cook County is in a flood zone?
Look up the address on FEMA's Flood Map Service Center or ask the local floodplain manager[27]. County-level ratings do not tell you the flood zone of a single address[27].

Facts and sources

  1. FEMA National Risk Index (version 1.20, December 2025): Expected Annual Loss from all 18 natural hazards in Cook County is $2.42 billion a year (Expected Annual Loss rating Very High, score 99.9). Of this, buildings account for $1.26 billion, injuries and deaths (converted to dollars by FEMA) for $1.16 billion and... FEMA National Risk Index
  2. OpenFEMA Disaster Declarations Summaries list 22 federal disaster declarations for natural hazards that include Cook County since 1967 (18 major disaster, 4 emergency or fire management). By incident type: flood 8, severe storm 8, snowstorm 4, tornado 1, hurricane 1. Biological (such as COVID-19) and other... OpenFEMA Disaster Declarations
  3. HazardFacts tally of OpenFEMA NFIP Redacted Claims (losses from 1978 to 2026): 15,260 National Flood Insurance Program claims were filed for losses in Cook County, 10,976 of them with a payment, and NFIP paid $139.8 million in total (building, contents and increased cost of compliance, in dollars of the year paid).... OpenFEMA NFIP claims
  4. NOAA Storm Prediction Center tornado database (1950 to 2024): 86 recorded tornadoes touched Cook County. The strongest were rated F4 (most recent of them on 1976-06-13). 4 were rated F3/EF3 or stronger. The most recent recorded tornado was on 2024-07-15. Ratings used the Fujita scale until early 2007 and the... NOAA Storm Prediction Center
  5. FEMA National Risk Index (version 1.20, December 2025): the overall natural hazard Risk Index rating for Cook County is Very High, with a Risk Index score of 99.9 out of 100. The score is the county's percentile rank among all US counties. FEMA National Risk Index
  6. Among the 18 hazards in the FEMA National Risk Index (version 1.20, December 2025), the hazards with the highest hazard-type Risk Index scores for Cook County are cold wave (100.0, Very High), winter weather (100.0, Very High), tornado (99.9, Very High). HazardFacts sorted FEMA's published scores; FEMA's scores... FEMA National Risk Index
  7. FEMA's National Risk Index FAQ (December 2025): Expected Annual Loss is FEMA's estimate of the average economic loss in dollars from natural hazards each year. The index is not meant to predict how much damage a community will have in the next year, and a hazard can still cause damage where a rating is low. Scores... FEMA National Risk Index documentation
  8. FEMA National Risk Index (version 1.20, December 2025), inland flooding in Cook County: Risk Index rating Very High (score 99.9 of 100). Expected Annual Loss $1.10 billion a year (rating Very High). Annualized frequency 5.89 event-days per year, from recorded occurrences over a period of record of 26 years. FEMA National Risk Index
  9. FEMA National Risk Index (version 1.20, December 2025), cold wave in Cook County: Risk Index rating Very High (score 100.0 of 100). Expected Annual Loss $700.0 million a year (rating Very High). Annualized frequency 4.25 event-days per year, from recorded occurrences over a period of record of 18 years. FEMA National Risk Index
  10. FEMA National Risk Index (version 1.20, December 2025), tornado in Cook County: Risk Index rating Very High (score 99.9 of 100). Expected Annual Loss $344.7 million a year (rating Very High). Annualized frequency 1.04 events per year, from recorded occurrences over a period of record of 38 years. FEMA National Risk Index
  11. FEMA National Risk Index (version 1.20, December 2025): Social Vulnerability rating for Cook County is Relatively High (score 61.7). FEMA describes social vulnerability as how susceptible social groups are to the harm natural hazards cause. FEMA National Risk Index
  12. FEMA National Risk Index (version 1.20, December 2025): Community Resilience rating for Cook County is Relatively High (score 73.2). FEMA describes community resilience as a community's ability to prepare for, withstand and recover from hazards. FEMA National Risk Index
  13. FEMA National Risk Index (version 1.20, December 2025), winter weather in Cook County: Risk Index rating Very High (score 100.0 of 100). Expected Annual Loss $4.4 million a year (rating Very High). Annualized frequency 14.6 events per year, from recorded occurrences over a period of record of 18 years. FEMA National Risk Index
  14. FEMA National Risk Index (version 1.20, December 2025), heat wave in Cook County: Risk Index rating Very High (score 99.8 of 100). Expected Annual Loss $193.4 million a year (rating Very High). Annualized frequency 2.9 event-days per year, from recorded occurrences over a period of record of 18 years. FEMA National Risk Index
  15. FEMA National Risk Index (version 1.20, December 2025), strong wind in Cook County: Risk Index rating Very High (score 99.5 of 100). Expected Annual Loss $11.6 million a year (rating Very High). Annualized frequency 5.7 events per year, from recorded occurrences over a period of record of 38 years. FEMA National Risk Index
  16. FEMA National Risk Index (version 1.20, December 2025), hail in Cook County: Risk Index rating Relatively High (score 99.1 of 100). Expected Annual Loss $11.1 million a year (rating Relatively High). Annualized frequency 3.95 events per year, from recorded occurrences over a period of record of 37 years. FEMA National Risk Index
  17. FEMA National Risk Index (version 1.20, December 2025), earthquake in Cook County: Risk Index rating Relatively High (score 98.4 of 100). Expected Annual Loss $57.3 million a year (rating Relatively High). FEMA's modeled annual frequency is 0.0013 events per year. FEMA National Risk Index
  18. FEMA National Risk Index (version 1.20, December 2025), lightning in Cook County: Risk Index rating Very High (score 98.1 of 100). Expected Annual Loss $2.7 million a year (rating Very High). Annualized frequency 41.54 events per year, from recorded occurrences over a period of record of 24 years. FEMA National Risk Index
  19. FEMA National Risk Index (version 1.20, December 2025), ice storm in Cook County: Risk Index rating Very High (score 97.1 of 100). Expected Annual Loss $2.0 million a year (rating Very High). Annualized frequency 0.58 event-days per year, from recorded occurrences over a period of record of 68 years. FEMA National Risk Index
  20. FEMA National Risk Index (version 1.20, December 2025), landslide in Cook County: Risk Index rating Very Low (score 56.3 of 100). Expected Annual Loss $1,810 a year (rating Very Low). FEMA National Risk Index
  21. FEMA National Risk Index (version 1.20, December 2025), wildfire in Cook County: Risk Index rating Very Low (score 55.7 of 100). Expected Annual Loss $56,000 a year (rating Very Low). FEMA's modeled annual frequency is 0.0002 events per year. FEMA National Risk Index
  22. FEMA National Risk Index (version 1.20, December 2025), hurricane in Cook County: Risk Index rating Very Low (score 48.8 of 100). Expected Annual Loss $57,000 a year (rating Very Low). Annualized frequency 0.01 events per year, from recorded occurrences over a period of record of 172 years for the Atlantic Basin... FEMA National Risk Index
  23. FEMA National Risk Index (version 1.20, December 2025), coastal flooding in Cook County: Risk Index rating Relatively Low (score 44.0 of 100). Expected Annual Loss $37,000 a year (rating Relatively Low). FEMA's modeled annual frequency is 0.0121 events per year. FEMA National Risk Index
  24. FEMA National Risk Index (version 1.20, December 2025), drought in Cook County: Risk Index rating Very Low (score 25.7 of 100). Expected Annual Loss $12,000 a year (rating Very Low). Annualized frequency 3.86 event-days per year, from recorded occurrences over a period of record of 22 years. FEMA National Risk Index
  25. FEMA National Risk Index (version 1.20, December 2025) rates these hazards Not Applicable for Cook County: avalanche, volcanic activity. FEMA uses Not Applicable when its source data has no historical record of the hazard in the community and the hazard is not considered geographically possible there. FEMA National Risk Index documentation
  26. NFIP Residential Penetration Rates (OpenFEMA, as of 2026-08-03): 6,353 residential flood insurance contracts were in force in Cook County, out of 1,241,949 residential structures, a penetration rate of 0.5%. Inside FEMA's mapped Special Flood Hazard Area there were 12,558 residential structures and 4,016 contracts,... OpenFEMA NFIP penetration rates
  27. FEMA's Flood Map Service Center is the official public source for flood maps (Flood Insurance Rate Maps) produced under the National Flood Insurance Program. Flood zones apply to specific properties: look up an address there or ask the local floodplain manager. County-level ratings do not tell you the flood zone of... FEMA Flood Map Service Center
  28. Most recent federal disaster declarations for natural hazards (table on this page). OpenFEMA Disaster Declarations

FEMA's National Risk Index compares each county with all other US counties. Ratings are relative (Very Low to Very High), not a measure of safety. Never call a place safe, unsafe, good or bad to live in. Risk Index and Expected Annual Loss values are FEMA estimates for planning. They do not predict next year's losses and do not apply to a single property. Flood zones are set by FEMA flood maps for specific properties. County ratings and flood insurance counts do not tell anyone whether an address is in a flood zone. Disaster declaration, NFIP and tornado counts are records of the past for this county only. Do not compare with other counties unless a fact does.

Federal Emergency Management Agency (FEMA), National Risk Index Dataset: National Risk Index Counties, v1.20 (December 2025). Retrieved from fema.maps.arcgis.com on October 30, 2026. This product uses the Federal Emergency Management Agency's National Risk Index dataset API or downloadable datasets but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s). This product uses the FEMA OpenFEMA API, but is not endorsed by FEMA.