How much flood risk does Dauphin County actually carry?
Dauphin County lands at the 94.8th percentile of FEMA's National Risk Index for flooding, "Relatively High" territory — well above the national norm for flood hazard — with the hazard driven by inland rivers and flash flooding rather than the coast — FEMA's model puts a flood event here at about 2 times a year. This describes the county, not any one street — FEMA only publishes exact parcel zones through a live map service.
Who actually carries the flood insurance FEMA requires
25.6% of the homes FEMA requires to carry flood insurance in Dauphin County — those inside the mapped Special Flood Hazard Area — actually have a policy in force: 862 policies against 3,368 mandated structures, which means a meaningful share of legally-required coverage simply isn't there. Across all residential structures in Dauphin County, not just the ones FEMA mandates, 1.2% carry an NFIP policy — most flood damage nationally happens outside the mapped high-risk zone, so that broader number matters too.
How Dauphin County compares nationally
Dauphin County sits at rank 178 of 3144 counties on FEMA's flood hazard scale (1 is worst) and rank 250 of 3144 by population (1 is biggest). Dauphin County, Pennsylvania covers 524.87 square miles and counts roughly 293,029 residents.
What to do next if you own or are buying in Dauphin County
FEMA counts 96,874 residential structures in Dauphin County overall, 1,130 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 Dauphin 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.