Updated May 2026
Is Your Home in a Flood Zone?
We analyzed 99,729 FEMA flood insurance claims and 1,403 disaster declarations to grade flood risk for every U.S. county on an A-to-F scale. Search your county to see its risk score, claims history, total payouts, and how it ranks nationally.
Riskiest Counties in America
Counties with the highest composite flood risk scores based on FEMA data.
| # | County | State | Grade | Risk Score | Total Claims | Disasters |
|---|---|---|---|---|---|---|
| 1 | Harris | TX | D | 74 | 11,742 | 25 |
| 2 | Lee | FL | C | 60 | 6,236 | 23 |
| 3 | Pinellas | FL | C | 55 | 4,890 | 22 |
| 4 | Jefferson | LA | B | 40 | 913 | 39 |
| 5 | Collier | FL | B | 39 | 2,036 | 26 |
| 6 | St. John the Baptist | LA | B | 39 | 647 | 38 |
| 7 | Terrebonne | LA | B | 39 | 131 | 44 |
| 8 | Lafourche | LA | B | 38 | 142 | 43 |
| 9 | St. Charles | LA | B | 38 | 265 | 42 |
| 10 | Hillsborough | FL | B | 37 | 1,930 | 23 |
Explore by State
View county-level flood risk data for any U.S. state.
Frequently Asked Questions
How do I find out if my county is in a flood zone?
Search your county using the search bar above to see its flood risk grade (A through F), total NFIP claims, disaster declarations, and cumulative payouts. Each county page shows a detailed breakdown of four risk factors: claims density, disaster frequency, claim severity, and year-over-year trend. For property-specific flood zone maps, visit FEMA's Flood Map Service Center at msc.fema.gov. Our county-level scores provide historical context that property-level maps do not, showing how often your area has actually flooded.
Which counties have the highest flood risk in the U.S.?
The counties with the highest flood risk are concentrated along the Gulf Coast, major river floodplains, and coastal areas prone to hurricanes. Counties in Louisiana, Texas, Florida, and Mississippi consistently score highest. Our ranking page shows the full list sorted by composite flood risk score, with Grade F counties representing the most extreme risk based on FEMA claims history and disaster declarations.
How is the flood risk score calculated?
Each county receives a composite flood risk score from 0 to 100, calculated as a weighted average of four factors: NFIP claims density (40%), which measures the volume of flood insurance claims per county; disaster declaration frequency (25%), counting federal flood-related disaster declarations; claim severity (20%), reflecting average payout per claim; and year-over-year trend (15%), tracking whether claims are increasing or decreasing. Each factor is normalized independently before combining. Data comes directly from FEMA OpenData, ensuring every score is grounded in real federal records rather than modeled estimates.
Do I need flood insurance if my area is low risk?
Yes, flood insurance is still worth considering even in low-risk areas. FEMA reports that over 25% of all flood insurance claims come from areas outside of designated high-risk flood zones, and just one inch of floodwater can cause over $25,000 in damage to a home. Standard homeowner's insurance does not cover flood damage. Our scores reflect county-wide historical patterns, but flood risk varies significantly by elevation, proximity to waterways, drainage infrastructure, and local development. Properties in FEMA-designated Special Flood Hazard Areas with federally backed mortgages are required to carry flood insurance.
Where does the data come from?
All data is sourced from FEMA OpenData, the federal government's public data portal for emergency management. We use two primary datasets: the Disaster Declarations Summaries (v2), which records every federally declared disaster filtered to flood-related incident types, and the FIMA NFIP Claims dataset, which contains aggregated flood insurance claim records by county. Both datasets are publicly available through the OpenFEMA API at no cost. This is U.S. government public domain data, the same information used by emergency managers, insurance actuaries, and floodplain administrators across the country.
What is the National Flood Insurance Program (NFIP)?
The NFIP is a federal program created by Congress in 1968 and managed by FEMA. It provides affordable flood insurance to property owners, renters, and businesses in participating communities. In exchange for access to federal flood insurance, communities must adopt and enforce floodplain management regulations that reduce future flood damage. Over 5 million NFIP policies are active across the United States, and the program has paid out over $70 billion in claims since its inception. Standard homeowner's insurance policies do not cover flood damage, which is why the NFIP exists as a dedicated flood insurance mechanism.
What is a FEMA flood zone?
FEMA flood zones are geographic areas mapped on Flood Insurance Rate Maps (FIRMs) according to their level of flood risk. High-risk zones (Special Flood Hazard Areas, designated as A and V zones) have a 1% or greater chance of flooding in any given year, commonly referred to as the 100-year floodplain. Properties in these zones with federally backed mortgages are required to carry flood insurance. Moderate-risk zones (B and X-shaded) have between 0.2% and 1% annual chance. Low-risk zones (C and X-unshaded) are above the 500-year flood level. FEMA periodically updates these maps as new flood data, terrain surveys, and development patterns change local risk profiles.
How do disaster declarations affect a county's score?
Federal disaster declarations are issued by the President when a state or locality experiences an event severe enough to warrant federal assistance beyond what state and local governments can handle on their own. For flood risk scoring, we count declarations involving flood-related incident types including floods, hurricanes, severe storms, coastal storms, and typhoons. Counties with more frequent declarations receive higher disaster frequency scores, which account for 25% of the composite risk score. A county that has received 10 or more flood-related disaster declarations over the FEMA record has a clear pattern of recurring, severe flooding that puts it at elevated long-term risk.
Can I compare flood risk between two counties?
Yes. Our Compare page shows side-by-side data for the 10 riskiest and 10 safest counties nationally, with grade badges, risk scores, and claims data. You can also visit individual county pages to see detailed breakdowns of all four score factors (claims density, disaster frequency, severity, and trend), total NFIP claims, cumulative payouts, and related counties in the same state. The state pages provide rankings of all counties within a state, making it easy to see how your county compares to its neighbors. For national context, our ranking pages sort all 3,000+ counties by various risk metrics.
Why does my county have a high score but few recent claims?
The flood risk score reflects historical patterns over the entire NFIP claims record, not just recent years. A county that experienced severe flooding in past decades but has had fewer recent events may still score high due to its cumulative claims density and disaster declaration history. The trend factor, which accounts for 15% of the composite score, does capture recent changes in claims volume. A county with declining claims will have a lower trend score, partially offsetting its historical factors. However, past flood patterns remain relevant because the underlying geographic risk factors (proximity to waterways, elevation, coastal exposure) typically do not change, even if there has been a temporary lull in flooding events.