Is Harrison County, MS in a flood zone?
FEMA's National Risk Index puts Harrison County's flood hazard at the 91.6th percentile nationally — well above the national norm for flood hazard — split between inland river flooding (about 1.8 times a year) and coastal storm surge (about 6.5 times a year). County-wide, not parcel-specific: FEMA's real flood-zone map is queried live, never shipped as a download.
Who actually carries the flood insurance FEMA requires
Homes with a federally backed mortgage inside Harrison 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, 62.5% of them do — 6,531 active policies against 10,451 structures FEMA counts in that zone, leaving a real compliance gap. Across all residential structures in Harrison County, not just the ones FEMA mandates, 14.5% carry an NFIP policy — most flood damage nationally happens outside the mapped high-risk zone, so that broader number matters too.
Harrison County against the rest of the country
Harrison County sits at rank 283 of 3144 counties on FEMA's flood hazard scale (1 is worst) and rank 331 of 3144 by population (1 is biggest). Harrison County, Mississippi covers 573.65 square miles and counts roughly 213,730 residents.
Checking a specific address in Harrison County
FEMA counts 73,384 residential structures in Harrison County overall, 10,601 of them carrying some form of NFIP coverage — but a lender or insurer cares about one parcel, not that county total.
More on how this number was built
The methodology guide shows exactly which FEMA and Census tables feed Harrison 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.