Updated May 2026
Riskiest Counties in America
The 100 U.S. counties with the highest composite flood risk scores based on FEMA claims, disaster declarations, and claim severity. Ranked using FEMA NFIP claim and federal disaster-declaration data from the public OpenFEMA API.
What This Ranking Tells You
The riskiest counties in America are dominated by Gulf Coast and lower-Mississippi geography. Harris leads with a composite score of 74 (grade D). Among the top 25 entries on this list, the four most-represented states are TX, FL, LA — a pattern that reflects how hurricane recurrence, storm surge, and barrier-island geography compound to produce sustained NFIP loss year after year.
The top 10 entries on this list average a composite risk score of 46 — well into the F (extreme) tier. These are counties where NFIP claim density, federal disaster frequency, claim severity, and recent trend all point in the same direction, and where homeowners typically face mandatory flood insurance under federally backed mortgages. For property-level decisions, pair this with the FEMA flood-zone designation at the parcel level and recent crest readings from USGS Water Data.
Top 100 by Risk Score
Grade mix across this list: 0 F · 1 D · 2 C · 47 B · 0 A. Click any county for the full profile, including the four factor scores that feed the composite, the full claim and disaster history, and the active NFIP policy count.
| # | County | State | Grade | Score | Risk Score |
|---|---|---|---|---|---|
| 1 | Harris | TX | D | 74 | 74 |
| 2 | Lee | FL | C | 60 | 60 |
| 3 | Pinellas | FL | C | 55 | 55 |
| 4 | Jefferson | LA | B | 40 | 40 |
| 5 | Collier | FL | B | 39 | 39 |
| 6 | St. John the Baptist | LA | B | 39 | 39 |
| 7 | Terrebonne | LA | B | 39 | 39 |
| 8 | Lafourche | LA | B | 38 | 38 |
| 9 | St. Charles | LA | B | 38 | 38 |
| 10 | Hillsborough | FL | B | 37 | 37 |
| 11 | Sarasota | FL | B | 36 | 36 |
| 12 | Calcasieu | LA | B | 36 | 36 |
| 13 | Plaquemines | LA | B | 36 | 36 |
| 14 | Manatee | FL | B | 35 | 35 |
| 15 | St. Bernard | LA | B | 35 | 35 |
| 16 | Broward | FL | B | 33 | 33 |
| 17 | Volusia | FL | B | 33 | 33 |
| 18 | East Baton Rouge | LA | B | 33 | 33 |
| 19 | Pasco | FL | B | 32 | 32 |
| 20 | Charlotte | FL | B | 32 | 32 |
| 21 | Gulf | FL | B | 32 | 32 |
| 22 | Escambia | FL | B | 32 | 32 |
| 23 | Santa Rosa | FL | B | 32 | 32 |
| 24 | Allen | LA | B | 32 | 32 |
| 25 | Avoyelles | LA | B | 32 | 32 |
| 26 | Franklin | FL | B | 31 | 31 |
| 27 | Okaloosa | FL | B | 31 | 31 |
| 28 | Baldwin | AL | B | 31 | 31 |
| 29 | Assumption | LA | B | 30 | 30 |
| 30 | Wakulla | FL | B | 29 | 29 |
| 31 | Walton | FL | B | 29 | 29 |
| 32 | Harrison | MS | B | 29 | 29 |
| 33 | La Salle | LA | B | 29 | 29 |
| 34 | Ascension | LA | B | 29 | 29 |
| 35 | Livingston | LA | B | 29 | 29 |
| 36 | Craven | NC | B | 29 | 29 |
| 37 | Citrus | FL | B | 28 | 28 |
| 38 | Beaufort | NC | B | 28 | 28 |
| 39 | Hyde | NC | B | 28 | 28 |
| 40 | Pender | NC | B | 28 | 28 |
| 41 | Hernando | FL | B | 27 | 27 |
| 42 | Orange | FL | B | 27 | 27 |
| 43 | Hancock | MS | B | 27 | 27 |
| 44 | St. Martin | LA | B | 27 | 27 |
| 45 | St. Mary | LA | B | 27 | 27 |
| 46 | West Feliciana | LA | B | 27 | 27 |
| 47 | Onslow | NC | B | 27 | 27 |
| 48 | Westchester | NY | B | 26 | 26 |
| 49 | Cameron | LA | B | 26 | 26 |
| 50 | West Baton Rouge | LA | B | 26 | 26 |
How These Ranks Are Calculated
The composite flood risk score combines four normalized factors — claims density (40%), disaster frequency (25%), claim severity (20%), and year-over-year trend (15%). Where this ranking uses a single direct metric (claims, payouts, disasters, or policies), counties are sorted by that field alone. Source: FEMA OpenFEMA (DisasterDeclarationsSummaries v2 and FimaNfipClaims). Full methodology: methodology page.
Frequently Asked Questions
How is "Risk Score" measured for this ranking?
For this ranking, counties are ordered by risk score drawn directly from FEMA OpenFEMA data — either NFIP claims totals, claim payouts, federal disaster declarations, active policies, or the four-factor composite score. Tied counties keep their natural alphabetical order. The composite-score formula and per-factor weights are documented on the methodology page.
Why are the same states dominating multiple rankings?
A small number of states — typically Louisiana, Texas, Florida, New York, and New Jersey — appear repeatedly across the riskiest-counties, most-claims, and highest-payouts lists. The cause is the same: hurricane and tropical-storm exposure puts a large share of the housing stock within reach of storm surge, and federally mandated flood-insurance rules in Special Flood Hazard Areas concentrate NFIP take-up there.
Does a high ranking mean every property in that county is at risk?
No. Rankings are county-level aggregates, and flood risk varies sharply within a single county. A coastal county can post huge claim totals from a few low-elevation neighborhoods while most of its land sits well above any flood crest. Always layer this with the parcel-level FEMA flood-zone designation from fema.gov/flood-maps.
How current is this ranking?
Rankings are recomputed every time the underlying FEMA dataset refreshes from the OpenFEMA API. The current dataset covers 3.3K counties, 100K NFIP claims, and was last updated on 2026-05-16.
Where does the underlying data come from?
Two FEMA datasets: DisasterDeclarationsSummaries v2 (federally declared disasters filtered to flood-related types) and FimaNfipClaims (individual NFIP claims aggregated by county FIPS code). Both are public-domain U.S. government work, distributed through the OpenFEMA API. Real-time stream-gauge context that complements the federal aggregates is at waterdata.usgs.gov.
Riskiest Counties in America: top 100 U.S. counties ranked by risk score from FEMA NFIP and disaster-declaration data.