FloodZoneMap.org

Cook County, Illinois Flood Zones

Check an Address in Cook County

Enter any address in Cook County, Illinois to see its FEMA flood zone

The Flooding Character of Cook County

Flash flooding from thunderstorms dominates the flood character of Cook County, IL. Between 1996 and 2023, NOAA data recorded 206 flood events and 184 flash flood events, resulting in 3 fatalities. For example, torrential rainfall caused widespread flash flooding across the Chicago metro area in August 2025, leading to an estimated $288 million in damages. Another event in July 2025 produced heavy rain and flash flooding across central Cook County.

National Flood Insurance Program (NFIP) claims data shows that properties in Zone A have filed the most claims (8,258), with an average payout of $9,471 and an average water depth of 3.9 feet. Properties in Zone X also experienced significant claims (2,186), with a higher average payout of $11,529 and an average water depth of 4.6 feet, despite being in a lower-risk zone. Homeowners in Zone A and Zone X should pay particular attention to their flood risk.

Summary generated from NOAA storm narratives and NFIP claim data for this county. Not predictive.

Read First-Hand Flood Stories from Cook County

125 NOAA storm reports from this county describe what happened, in the words of the meteorologists who were there.

Read Illinois flood stories →

Flood Risk Data for Cook County

Cook County, Illinois has recorded 393 flood-related events since 1996 according to NOAA's Storm Events Database, including 184 flash floods and 206 river or area floods. The county has received 24 federal disaster declarations, 8 of which involved flooding or coastal storms. Enter any address above to check its FEMA flood zone designation.

Cook County Disaster History

FEMA Disaster Declarations (1967–2024)

Disaster Declarations
24
Flood/Coastal Disasters
8
Latest Disaster
Severe Storms, Tornadoes, Straight-line Winds, And Floodng (2024-07-13)

Source: OpenFEMA Disaster Declarations Summaries.

Recent Disaster Declarations in Cook County

DeclarationTypeDate
Severe Storms, Tornadoes, Straight-line Winds, And FloodngFloodJul 13, 2024
Severe Storms And FloodingFloodSep 17, 2023
Severe Storms And FloodingSevere StormJun 29, 2023
Covid-19BiologicalJan 20, 2020
Covid-19 PandemicBiologicalJan 20, 2020
Severe Storms, Straight-line Winds, And FloodingFloodApr 16, 2013
Severe Winter Storm And SnowstormSnowstormJan 31, 2011
Severe Storms And FloodingSevere StormJul 19, 2010
Severe Storms And FloodingSevere StormSep 13, 2008
Severe Storms And FloodingSevere StormAug 20, 2007

Recorded Flood Events in Cook County

NOAA Storm Events Database (1996–2025)

Total Flood Events
393
River/Area Floods
206
Flash Floods
184
Coastal/Storm Surge
3
Total Property Damage
$1.6B
Flood Deaths
3

Source: NOAA National Weather Service Storm Events Database.

Recent Flood Events in Cook County

TypeDateDamage
FloodJan 31, 20250.00K
FloodJul 28, 20250.00K
FloodJul 25, 20250.00K
Flash FloodJul 25, 2025200.00M
FloodJul 24, 20250.00K
Flash FloodJul 24, 20250.00K
FloodJun 18, 20250.00K
Flash FloodAug 18, 20251.50M
Flash FloodAug 18, 20253.50M
Flash FloodAug 18, 20252.50M

Cook County Flood History

Flood — Jan 31, 2025

Persistent moderate to heavy rain during the morning of the 31st resulted in a few instances of localized flooding, mainly around the interior Chicago metro area. Despite rain reports largely below 1.5, NWS Chicago recorded a 12 frost depth in Romeoville on the morning of the 31st, which made the area more susceptible to flooding.

Flood — Jul 28, 2025

Isolated thunderstorms moved across portions of northeast Illinois during the afternoon of July 28th.

Flood — Jul 25, 2025

Isolated thunderstorms produced funnel clouds across central Illinois during the late morning of July 25th. A narrow line of thunderstorms developed over southeast DuPage and central Cook Counties during the late morning of July 25th and continued into the early afternoon producing torrential rainfall and widespread flash flooding. Scattered thunderstorms moved across portions of northern Ill...

Flash Flood — Jul 25, 2025

Isolated thunderstorms produced funnel clouds across central Illinois during the late morning of July 25th. A narrow line of thunderstorms developed over southeast DuPage and central Cook Counties during the late morning of July 25th and continued into the early afternoon producing torrential rainfall and widespread flash flooding. Scattered thunderstorms moved across portions of northern Ill...

Flood — Jul 24, 2025

Scattered thunderstorms produced significant wind damage across portions of the Chicago Metro area during the afternoon of July 24th.

Source: NOAA National Weather Service Storm Events Database.

Cook County NFIP Flood Insurance Claims

Total Claims Filed
12,560
Total Paid Out
$116.6M
Avg Claim
$12,917
Avg Water Depth
9.7 ft

Claims by Flood Zone

A Zones (High Risk)
8,258
V Zones (Coastal)
6
X Shaded (500-yr)
515
X Unshaded (Low)
1,013

Source: OpenFEMA NFIP Individual Claims (2.25M records analyzed).

Flood Zone Types in Cook County

FEMA assigns flood zone designations to areas in Cook County, Illinois:

AE High Risk — 1% annual chance of flooding. Insurance required.

VE Very High Risk — Coastal flooding with wave action.

X (Shaded) Moderate Risk — 500-year floodplain.

X Low Risk — Outside major floodplains.

View all flood zone types →

Flood Insurance in Cook County

Properties in Cook County, Illinois that are in FEMA-designated Special Flood Hazard Areas (zones A and V) with federally backed mortgages are required to carry flood insurance.

Even outside high-risk zones, flood insurance is recommended. From 2014 to 2024, nearly one-third of NFIP claims came from outside the high-risk Special Flood Hazard Area.

Visit FloodSmart.gov to find an agent and get a quote.