Union County Disaster Risk

Union County has a FEMA National Risk Index rating of Relatively Low, placing it in the 50th 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.

Union County is evaluated for five major natural hazard types: tornado (57th percentile), wildfire (50th percentile), flooding (30th percentile), earthquake (24th percentile), hurricane (11th percentile). The highest-risk hazard is tornado at the 57th 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.

Union County's composite risk percentile is 50th, compared to the Iowa state average of 40th percentile. The state's overall risk rating is Very Low. This means Union County faces higher natural disaster risk than the typical county in Iowa.

Yes, Union County's tornado risk is at the 57th percentile nationally. This is above the national median. For flooding specifically, Union County is at the 30th 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.

Union County's composite risk score of 50th percentile is above the Iowa state average of 40th percentile. This elevated risk is driven by tornado exposure (57th percentile). Geographic location, terrain, climate patterns, and proximity to flood zones or fault lines all influence a county's risk profile.