Johnston County, OK: flood risk, in FEMA's own numbers
On FEMA's National Risk Index, Johnston County scores at the 19.1th percentile for flood hazard, rated "Very Low" — among the lowest flood hazard in the country. The hazard here is driven by inland rivers and flash flooding rather than the coast — FEMA's model puts a flood event here at about once every 1 years. County-wide, not parcel-specific: FEMA's real flood-zone map is queried live, never shipped as a download.
Johnston County's flood-insurance compliance gap
FEMA hasn't published a residential structure count for Johnston County's mapped flood zone, so a reliable mandatory-compliance percentage can't be computed here — see the data quality guide for why this gap exists for roughly a quarter of US counties. Looking beyond the mandated zone, 0% of all residential structures in Johnston County carry flood coverage voluntarily or otherwise — relevant because most NFIP claims nationally come from outside the mapped SFHA.
How Johnston County compares nationally
Among the 3144 US counties FEMA scores for flood hazard, Johnston County ranks 2583 — 1 being the highest hazard nationally — and 2388 by population among all 3144 counties covered here, where 1 is the largest. About 10,293 people live in Johnston County, Oklahoma, spread over 643.05 square miles.
What to do next if you own or are buying in Johnston County
FEMA counts 4,880 residential structures in Johnston County overall, 2 of them carrying some form of NFIP coverage — but a lender or insurer cares about one parcel, not that county total.
Where Johnston County's figures come from
Every figure on this page traces to a named FEMA dataset, documented in the methodology guide. Johnston County's compliance figure is one of the ones affected by FEMA's incomplete denominator data — the data quality guide explains what that means and how many counties it touches.