Johnson County Disaster Risk

Johnson County has a FEMA National Risk Index rating of Relatively Low, placing it in the 75th 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.

Johnson County is evaluated for five major natural hazard types: tornado (89th percentile), earthquake (82th percentile), flooding (79th percentile), wildfire (20th percentile), hurricane (11th percentile). The highest-risk hazard is tornado at the 89th 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.

Johnson County's composite risk percentile is 75th, compared to the Indiana state average of 46th percentile. The state's overall risk rating is Relatively Low. This means Johnson County faces higher natural disaster risk than the typical county in Indiana.

Yes, Johnson County's tornado risk is at the 89th percentile nationally. This places it in the top quartile for this hazard type. For flooding specifically, Johnson County is at the 79th 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.

Johnson County's composite risk score of 75th percentile is above the Indiana state average of 46th percentile. This elevated risk is driven by tornado exposure (89th percentile), along with earthquake and flooding risk. Geographic location, terrain, climate patterns, and proximity to flood zones or fault lines all influence a county's risk profile.