Is Coos County, NH in a flood zone?
FEMA's National Risk Index puts Coos County's flood hazard at the 77.6th percentile nationally — a middling flood hazard by national standards — driven by inland rivers and flash flooding rather than the coast — FEMA's model puts a flood event here at about 2.4 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
Out of 636 homes FEMA counts inside Coos County's mapped flood zone, 71 carry the flood policy federal law requires there — 11.2% compliance, short of full coverage. Across all residential structures in Coos County, not just the ones FEMA mandates, 0.6% carry an NFIP policy — most flood damage nationally happens outside the mapped high-risk zone, so that broader number matters too.
Where Coos County ranks
Coos County sits at rank 734 of 3144 counties on FEMA's flood hazard scale (1 is worst) and rank 1411 of 3144 by population (1 is biggest). Coos County, New Hampshire is home to about 31,094 people across 1,794.574 square miles of land.
What to do next if you own or are buying in Coos County
Across all of Coos County's 14,285 residential structures, 84 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 Coos County's numbers. The guide to what the Special Flood Hazard Area actually means explains why the mandatory-insurance rule exists and who it applies to.