County FEMA disaster declaration summary

In one line

Every U.S. county's FEMA disaster-declaration history (3,266 counties, 1959–2026): total declarations, major (federally-significant) declarations, the most common incident type, and the first/latest declaration year -- the same figures rendered on every county page, packaged as a real downloadable file.

Before you count rows: one declaration is many rows

The Disaster Declarations Summaries payload emits one row per designated area, not one row per declaration. A single declaration naming dozens of townships appears dozens of times, so COUNT(*) grouped by county overstates that county's declaration history, often several-fold. In the snapshot behind this site, 70,066 rows resolve to 5,218 distinct declarations, and the worst-affected county carries 6.2× more rows than declarations.

Counting DISTINCT disasterNumber within each county is the fix. Every figure on this site already does, which is why our per-county totals are lower than a naive row count of the same source. That gap is the duplication, not a discrepancy.

If you would rather not re-derive it: every entity page publishes its own de-duplicated CSV: county, state, hazard and disaster type, at /<type>/<slug>.csv. For the API reference itself, use FEMA's OpenFEMA dataset documentation; this page does not restate it.

Provenance

Original source

FEMA OpenFEMA Disaster Declarations Summaries (public domain)

Derived presentation license

CC0 (no rights reserved)

Data vintage

2026-08-25

Coverage

3,266 U.S. counties, 1959–2026

Every number in this download matches the corresponding county page exactly -- no re-aggregation, no rounding beyond what's already shown. See methodology for the full derivation.