How much flood risk does Siskiyou County actually carry?
Siskiyou County lands at the 90.9th 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 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 Siskiyou County
Out of 1,821 homes FEMA counts inside Siskiyou County's mapped flood zone, 156 carry the flood policy federal law requires there — 8.6% compliance, short of full coverage. Across all residential structures in Siskiyou County, not just the ones FEMA mandates, 0.8% carry an NFIP policy — most flood damage nationally happens outside the mapped high-risk zone, so that broader number matters too.
Where Siskiyou County ranks
Siskiyou County sits at rank 307 of 3144 counties on FEMA's flood hazard scale (1 is worst) and rank 1139 of 3144 by population (1 is biggest). About 42,498 people live in Siskiyou County, California, spread over 6,278.767 square miles.
What to do next if you own or are buying in Siskiyou County
FEMA counts 22,883 residential structures in Siskiyou County overall, 181 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 Siskiyou 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.