How much flood risk does Miami-Dade County actually carry?
Miami-Dade County lands at the 99.7th percentile of FEMA's National Risk Index for flooding, "Very High" territory — among the highest flood hazard in the country — with the hazard split between inland river flooding (about 4 times a year) and coastal storm surge (about 2.3 times a year). That's a county-wide figure, not a per-address one — FEMA's parcel maps are a live lookup, not a bulk file.
Who actually carries the flood insurance FEMA requires
Homes with a federally backed mortgage inside Miami-Dade County's mapped high-risk flood zone (the Special Flood Hazard Area, or SFHA) are legally required to carry an NFIP flood policy. In practice, 74.5% of them do — 148,389 active policies against 199,250 structures FEMA counts in that zone, leaving a real compliance gap. Across all residential structures in Miami-Dade County, not just the ones FEMA mandates, 33.4% carry an NFIP policy — most flood damage nationally happens outside the mapped high-risk zone, so that broader number matters too.
Miami-Dade County against the rest of the country
Miami-Dade County sits at rank 12 of 3144 counties on FEMA's flood hazard scale (1 is worst) and rank 7 of 3144 by population (1 is biggest). Miami-Dade County, Florida is home to about 2,838,461 people across 1,899.988 square miles of land.
Your street may differ from Miami-Dade County's average
Across all of Miami-Dade County's 492,181 residential structures, 164,154 carry an NFIP policy today — a county-wide count that still can't tell you one address's own mapped zone.
More on how this number was built
The methodology guide shows exactly which FEMA and Census tables feed Miami-Dade 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.