Biological disasters in the United States

How common are Biological disasters in the U.S.?

Geographic concentration is pronounced for this disaster type. The three states with the most biological declarations on record are OK (17 declarations), NM (13 declarations), NE (6 declarations), driven mainly by which states sit in the relevant hazard corridor. States with the fewest declarations, including WI (2), WV (2), WY (2), generally facing less exposure to this hazard type, though physiographic coverage still varies.

FEMA has issued 167 federal disaster declarations classified as biological between 2020 and 2021, affecting 56 states and territories. Each declaration represents a formal federal recognition that an event exceeded state and local response capacity, unlocking Public Assistance, Individual Assistance, or Hazard Mitigation Grant Program funding depending on the declaration class (DR, EM, or FM). Raw declaration counts therefore measure the federal response footprint, which is a lagging and thresholded indicator: smaller events handled entirely at the state level never appear, and declaration thresholds have been recalibrated over the dataset's multi-decade history.

Temporal patterns in the record tell a separate story. The peak year on record was 2020, with 165 biological declarations issued that single year, a clustering driven by major multi-state events and the federal government's declaration cadence. The most recent year on record is 2021, with 2 declarations. Trends over the 1+ year history reflect changing federal declaration policy alongside real shifts in event frequency.