St. Charles County
Missouri — Natural Disaster Risk Assessment
MediumComposite Risk Score
National percentile: 93th
St. Charles County faces medium composite natural disaster risk (NRI Risk Index score 92.6, 93th national percentile), driven primarily by strong wind and hail exposure. Expected annual loss across all 18 hazard types is $215M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Top Hazards
All 18 Hazard Risks
| Strong Wind | Very High | 5.89 / yr | $10M |
| Hail | High | 5.29 / yr | $9M |
| Tornado | High | 0.46 / yr | $28M |
| Heat Wave | Medium | 14.74 / yr | $12M |
| Earthquake | Medium | 0.00 / yr | $22M |
| Riverine Flood | High | 2.07 / yr | $116M |
| Landslide | Medium | 0.44 / yr | $144K |
| Cold Wave | High | 1.74 / yr | $15M |
| Lightning | High | 50.98 / yr | $2M |
| Winter Weather | High | 8.79 / yr | $658K |
| Ice Storm | Medium | 1.29 / yr | $416K |
| Wildfire | Very Low | 0.00 / yr | $135K |
| Drought | Low | 1.92 / yr | $56K |
| Hurricane | Very Low | 0.01 / yr | $13K |
| Avalanche | Very Low | 0.00 / yr | $0 |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
| Volcanic Activity | Very Low | 0.00 / yr | $0 |
Frequently Asked Questions
What is the overall natural disaster risk for St. Charles County?
St. Charles County has a composite FEMA National Risk Index score of 92.6 out of 100, placing it in the Medium category and the 93th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in St. Charles County?
The three highest-rated hazards are Strong Wind (Very High, $10M EAL), Hail (High, $9M EAL), Tornado (High, $28M EAL). These account for most of the county's expected annual losses.
How does St. Charles County compare to other Missouri counties?
St. Charles County ranks #4 of 115 Missouri counties for overall natural disaster risk, with a medium rating.
What does Expected Annual Loss (EAL) mean?
EAL is FEMA's estimate of average annual dollar losses from natural hazards, calculated from historical event data and exposure models. St. Charles County's $215M EAL is a statistical average, not a guarantee for any specific year or address.