Chicago, IL Flood Zone Map
Last updated: August 2026
Chicago faces flooding from Lake Michigan storm surge, the Chicago River system, and intense urban rainfall overwhelming the combined sewer system. Basement flooding is a pervasive problem throughout the metropolitan area.
Cook County has recorded 15,230 NFIP flood insurance claims since 1978, totaling $139.1M in payouts. Explore the full NFIP claims data by state and county to see how this area compares nationally.
FEMA Region
Region 5
NFIP Policies
13,634
Cook County
Avg. Premium
$809/yr
Cook County
NFIP Flood Insurance Claims: Cook County
Properties in Cook County have filed 15,230 NFIP flood insurance claims totaling $139.1M in payouts since 1978. The average claim payout is $9K.
Highest-Claim Years
2008
2,048 claims - $33.7M
2013
1,981 claims - $35.5M
2010
1,559 claims - $18.1M
Claims by Flood Zone
Source: OpenFEMA NFIP Claims API. Data sourced August 2026. See national claims data.
Flood Insurance Coverage: Cook County
Only roughly 1 in 153 households in Cook County carries NFIP flood insurance (0.7% of estimated households). With 400 recorded flood events and $1.6B in damage, most flood losses in this county are likely uninsured.
Penetration Rate
0.7%
roughly 1 in 153 households
Historical Claims Ratio
1 in 1
15,230 claims over 45+ years across 13,634 current policies
Avg. Claim Payout
$9,136
Per claim, county-wide since 1978
Historically, Cook County has averaged 1.1 claims for every active policy (since 1978). This compares cumulative claims against today's policy count and does not predict future claim likelihood.
Coverage data: NFIP policies as of August 2026, claims since 1978 (August 2026), population from FEMA NRI. All figures are county-wide and include Chicago.
Not sure whether you're required to carry it? See do I need flood insurance?, or compare NFIP vs. private flood insurance.
Repetitive Loss Properties: Cook County
Cook County has 1,651 properties with multiple flood insurance losses, including 115 severe repetitive loss properties. 44 properties have received FEMA mitigation funding. Severe repetitive loss is a subset of multiple loss, not a separate count. Data sourced August 2026.
Multiple Loss
1,651
2+ claims within 10 years
Severe Repetitive Loss
115
4+ claims or 2 exceeding value
Mitigated
44
Received FEMA mitigation
By Flood Zone
Zone data available for 1,631 of 1,651 properties.
Source: OpenFEMA NFIP Multiple Loss Properties. Data sourced August 2026.
Federal Flood Disaster History: Cook County
Cook County has been included in 9 federal flood-related disaster declarations.
...and 1 earlier declaration since 1972.
These declarations affected communities across Cook County, including Chicago.
Source: OpenFEMA Disaster Declarations Summaries API. Data sourced August 2026.
Recorded Flood Events: Cook County
NOAA has recorded 400 flood events in Cook County since 1996, causing $1.6B in damage and 3 deaths.
Costliest Events
Events by Type
Source: NOAA Storm Events Database, 1996-2026. Data sourced August 2026.
Flood Mitigation: Cook County
FEMA has funded mitigation for 2,762 properties in Cook County, investing $35.6M in flood risk reduction. Common mitigation actions include acquisition (buying and demolishing flood-prone structures), elevation (raising buildings above flood level), and safe rooms (wind/storm shelters for tornado and hurricane protection).
By Action Type
Source: OpenFEMA Hazard Mitigation Assistance. Data sourced August 2026. FEMA records a total payment per grant rather than per property, so the dollar figure is an estimate that splits each grant across the properties it covers; the property count is exact.
FEMA Flood Risk Profile: Cook County
Based on FEMA's National Risk Index, which evaluates flood risk at the county level using historical loss data, exposure, and vulnerability.
Inland Flood Risk
Very HighEst. annual loss: $1.1B
Coastal Flood Risk
Relatively LowEst. annual loss: $37K
Hurricane Risk
Very LowEst. annual loss: $57K
Source: FEMA National Risk Index, county-level assessment. Individual property risk may vary.
What Your Flood Zone Means in Chicago
Chicago faces multiple inland flood threats, including riverine flooding from nearby waterways and flash flooding from intense rainfall overwhelming urban drainage systems. Properties near river corridors face the highest risk, but stormwater backup can affect neighborhoods well outside the mapped floodplain. The most common FEMA flood zone designations in Chicago are Zone AE, Zone AO, Zone X. FEMA's National Risk Index estimates the county's annual expected loss from inland flooding at over $1.1B. Chicago has Zone AO areas subject to sheet-flow flooding, where shallow water spreads across broad, flat terrain rather than channeling through waterways.
With both riverine and urban stormwater flood risk, insurance costs in Chicago depend heavily on a property's elevation relative to nearby waterways and the local drainage infrastructure. FEMA's Risk Rating 2.0 prices in multiple inland flood sources rather than relying on the flood zone line alone. If your property is in a Special Flood Hazard Area (SFHA) and you have a federally regulated or government-backed mortgage, federal law generally requires your lender to ensure you carry flood insurance.
Flood zone boundaries in Chicago can shift when FEMA updates its Flood Insurance Studies or when upstream development changes how water moves through the watershed. New stormwater infrastructure or dam modifications can also trigger map revisions. Use our free lookup tool to check the current flood zone for any Chicago address.
Chicago, IL Flood Zone FAQ
What flood zones are in Chicago, IL?
The most common FEMA flood zones in Chicago are Zone AE, Zone AO, Zone X. Properties in these high-risk zones (SFHA) may require flood insurance with a federally regulated or government-backed mortgage.
Is flood insurance required in Chicago?
If your Chicago property is in a Special Flood Hazard Area (SFHA) and you have a federally regulated or government-backed mortgage, federal law generally requires your lender to ensure you carry flood insurance. Properties in Zone X are not federally required to carry flood insurance, though coverage is still recommended since about a quarter of all NFIP flood claims come from properties outside high-risk zones.
How do I check my flood zone in Chicago?
Enter your Chicago address in the search tool above for an instant flood zone determination. Results include your FEMA flood zone, SFHA status, base flood elevation (if available), and FIRM panel information, pulled directly from FEMA's National Flood Hazard Layer.
How high is flood risk in Chicago?
According to FEMA's National Risk Index, Cook County (where Chicago is located) has a "Very High" rating for inland flood risk. The estimated annual flood loss for the county is $1.1B. This county-level assessment considers historical flood losses, social vulnerability, and community resilience.
Has Chicago experienced major flooding events?
Cook County, where Chicago is located, has been part of 9 federal disaster declarations for flooding, hurricanes, or severe storms. The most recent was Severe Storms, Tornadoes, Straight-Line Winds, and Floodng in 2024. Federal disaster declarations are issued when flooding overwhelms local resources and triggers FEMA assistance programs.
How many flood insurance claims have been filed in Chicago?
Cook County has recorded 15,230 NFIP flood insurance claims totaling $139.1M in payouts since 1978. The year with the most claims was 2008, with 2,048 claims and $33.7M in payouts. These figures cover all NFIP claims in the county, including Chicago.
How many flood insurance policies are there in Chicago?
Cook County had 13,634 NFIP flood insurance policies written or renewed over the trailing 13 months, with an average annual premium of $809. The most policies are in Zone AE (6,964 policies). These are county-level counts of policies written or renewed in the trailing 13 months, not a point-in-time count of policies in force - a policy renewed inside that window is counted twice.
How many Chicago properties have flooded repeatedly?
Cook County has 1,651 properties with multiple flood losses on record, including 115 severe repetitive loss properties. These are properties that have experienced four or more NFIP claims of $5,000+ or two claims exceeding the building value.
Can my Chicago property be removed from a high-risk flood zone?
Yes, if your property's natural ground elevation is above the Base Flood Elevation and FEMA inadvertently mapped it in a high-risk zone, you can apply for a Letter of Map Amendment (LOMA). A successful LOMA removes the property from the Special Flood Hazard Area, generally eliminating the federal mandatory flood insurance requirement. You will need an elevation certificate from a licensed surveyor. If a property was raised above the BFE with fill material, the process is a LOMR-F rather than a LOMA.
What is Base Flood Elevation in Chicago?
Base Flood Elevation (BFE) is the predicted height of floodwaters during a 1% annual chance (100-year) flood, shown on FEMA maps as an elevation number in feet above sea level. In Chicago's Zone AE areas, BFE lines appear on the FIRM as wavy contours labeled with elevation values. Properties with a lowest floor at or above the BFE typically qualify for significantly lower NFIP flood insurance premiums.
Other Illinois Cities
Understanding Flood Zones
See the Flood Map for Any Chicago, IL Address
Enter a Chicago, IL address to view its FEMA flood map, zone designation, SFHA status, and insurance requirements.
Disclaimer: Flood risk data on this page is sourced from FEMA datasets including the National Risk Index, NFIP claims and policy records, disaster declarations, and the Community Rating System. These datasets were last extracted on August 2026 and may not reflect the most recent changes. Always verify current flood zone status through FEMA or a licensed determination provider before making property, insurance, or lending decisions.