St. Charles County Disaster Risk

St. Charles County has a FEMA National Risk Index rating of Relatively Moderate, placing it in the 93th 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.

St. Charles County is evaluated for five major natural hazard types: tornado (96th percentile), earthquake (95th percentile), flooding (94th percentile), wildfire (59th percentile), hurricane (23th percentile). The highest-risk hazard is tornado at the 96th 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.

St. Charles County's composite risk percentile is 93th, compared to the Missouri state average of 51th percentile. The state's overall risk rating is Relatively Low. This means St. Charles County faces higher natural disaster risk than the typical county in Missouri.

Yes, St. Charles County's tornado risk is at the 96th percentile nationally. This places it in the top quartile for this hazard type. For flooding specifically, St. Charles County is at the 94th 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.

St. Charles County's composite risk score of 93th percentile is above the Missouri state average of 51th percentile. This elevated risk is driven by tornado exposure (96th percentile), along with earthquake and flooding and wildfire risk. Geographic location, terrain, climate patterns, and proximity to flood zones or fault lines all influence a county's risk profile.