Middlesex County, MA flood risk explained
Flood hazard in Middlesex County sits at the 98.5th national percentile, well above the national norm for flood hazard; driven by inland rivers and flash flooding rather than the coast — FEMA's model puts a flood event here at about 4.3 times a year. That's a county-wide figure, not a per-address one — FEMA's parcel maps are a live lookup, not a bulk file.
Middlesex County's flood-insurance compliance gap
Out of 4,035 homes FEMA counts inside Middlesex County's mapped flood zone, 2,159 carry the flood policy federal law requires there — 53.5% compliance, short of full coverage. Looking beyond the mandated zone, 1% of all residential structures in Middlesex County carry flood coverage voluntarily or otherwise — relevant because most NFIP claims nationally come from outside the mapped SFHA.
Middlesex County against the rest of the country
Among the 3144 US counties FEMA scores for flood hazard, Middlesex County ranks 53 — 1 being the highest hazard nationally — and 20 by population among all 3144 counties covered here, where 1 is the largest. Middlesex County, Massachusetts is home to about 1,668,956 people across 817.905 square miles of land.
Checking a specific address in Middlesex County
Across all of Middlesex County's 390,642 residential structures, 4,000 carry an NFIP policy today — a county-wide count that still can't tell you one address's own mapped zone.
Where Middlesex County's figures come from
Every figure on this page traces to a named FEMA dataset, documented in the methodology guide. If you're unsure why any of this insurance requirement exists at all, the SFHA explainer covers it from first principles.