Homeowners insurance doesn't cover flooding. That takes a separate policy, almost always from FEMA's National Flood Insurance Program, and most homes don't have one, even where the floods keep coming. Here's who's covered in every county, what the program has paid out since 1978, and how many of the homes under the heaviest recent rain were insured.
Policies. FEMA publishes every NFIP policy term through OpenFEMA. Counted here: the residential policies in force on the snapshot date, per county. "Share insured" divides them by the county's occupied homes (Census ACS 2020–2024). One condominium-association policy covers a whole building but counts once, so condo-heavy coastal counties read lower than they really are. Private flood insurance, a small but growing share, isn't in FEMA's data.
Claims. Every NFIP claim since 1978: building, contents and increased-cost-of-compliance payments, in the dollars of the year paid.
Rain. NOAA's URMA analysis, 2.5 km every six hours, sampled at the center of every census tract. Each tract gets the wettest 72 hours in the window, and the tract's homes count when that total reaches the threshold. Insured homes are estimated with the county's share insured, since policies aren't matched to individual homes. Heavy rain isn't the same as flooding, but it's where flooding starts, and NFIP claims show that much flood damage happens outside the mapped high-risk zones.