Brown County Disaster Risk

Brown County has a FEMA National Risk Index rating of Relatively Low, placing it in the 74th percentile nationally out of 3,144 counties. This composite score reflects the county's overall exposure to natural hazards including floods, wildfires, tornadoes, earthquakes, and hurricanes, weighted by expected annual loss and social vulnerability.

Brown County is evaluated for five major natural hazard types: wildfire (77th percentile), tornado (70th percentile), flooding (63th percentile), earthquake (28th percentile). The highest-risk hazard is wildfire at the 77th percentile nationally. These scores are derived from FEMA's National Risk Index, which analyzes expected annual loss, social vulnerability, and community resilience for each hazard type.

Brown County's composite risk percentile is 74th, compared to the South Dakota state average of 27th percentile. The state's overall risk rating is Very Low. This means Brown County faces higher natural disaster risk than the typical county in South Dakota.

Yes, Brown County's wildfire risk is at the 77th percentile nationally. This places it in the top quartile for this hazard type. For flooding specifically, Brown County is at the 63th percentile.

FEMA's National Risk Index (NRI) calculates risk scores for 18 natural hazard types across all U.S. counties and census tracts. The composite score combines Expected Annual Loss (estimated dollar losses from each hazard), Social Vulnerability (demographic factors affecting disaster impact), and Community Resilience (ability to recover). Percentile scores rank each county against all 3,144 U.S. counties, and risk ratings range from Very Low to Very High.

Brown County's composite risk score of 74th percentile is above the South Dakota state average of 27th percentile. This elevated risk is driven by wildfire exposure (77th percentile), along with tornado and flooding risk. Geographic location, terrain, climate patterns, and proximity to flood zones or fault lines all influence a county's risk profile.