How much flood risk does Dukes County actually carry?
Dukes County lands at the 55.4th percentile of FEMA's National Risk Index for flooding, "Relatively Low" territory — below the national norm for flood hazard — with the hazard driven by coastal storm surge rather than inland rivers — FEMA's model puts a surge event here at about 3.7 times a year. County-wide, not parcel-specific: FEMA's real flood-zone map is queried live, never shipped as a download.
Dukes County's flood-insurance compliance gap
53.2% of the homes FEMA requires to carry flood insurance in Dukes County — those inside the mapped Special Flood Hazard Area — actually have a policy in force: 359 policies against 675 mandated structures, which means a meaningful share of legally-required coverage simply isn't there. Across all residential structures in Dukes County, not just the ones FEMA mandates, 5.3% carry an NFIP policy — most flood damage nationally happens outside the mapped high-risk zone, so that broader number matters too.
Where Dukes County ranks
Dukes County sits at rank 1466 of 3144 counties on FEMA's flood hazard scale (1 is worst) and rank 1768 of 3144 by population (1 is biggest). About 21,061 people live in Dukes County, Massachusetts, spread over 103.202 square miles.
What to do next if you own or are buying in Dukes County
716 of Dukes County's 13,498 residential structures carry flood coverage of some kind, per FEMA's latest count — useful context, not a substitute for checking one parcel.
More on how this number was built
The methodology guide shows exactly which FEMA and Census tables feed Dukes County's numbers. Because storm surge plays a real role here, the guide to coastal vs. inland flood hazard is worth reading alongside this page.