How much flood risk does Armstrong County actually carry?
Armstrong County lands at the 85.1th percentile of FEMA's National Risk Index for flooding, "Relatively Moderate" territory — a middling flood hazard by national standards — with the hazard driven by inland rivers and flash flooding rather than the coast — FEMA's model puts a flood event here at about 1.7 times a year. County-wide, not parcel-specific: FEMA's real flood-zone map is queried live, never shipped as a download.
Mandatory flood insurance compliance in Armstrong County
8.5% of the homes FEMA requires to carry flood insurance in Armstrong County — those inside the mapped Special Flood Hazard Area — actually have a policy in force: 182 policies against 2,135 mandated structures, which means a meaningful share of legally-required coverage simply isn't there. Across all residential structures in Armstrong County, not just the ones FEMA mandates, 0.7% carry an NFIP policy — most flood damage nationally happens outside the mapped high-risk zone, so that broader number matters too.
Where Armstrong County ranks
Armstrong County sits at rank 492 of 3144 counties on FEMA's flood hazard scale (1 is worst) and rank 858 of 3144 by population (1 is biggest). About 63,679 people live in Armstrong County, Pennsylvania, spread over 653.321 square miles.
Your street may differ from Armstrong County's average
Across all of Armstrong County's 30,974 residential structures, 212 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 Armstrong 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.