St. Louis County
Missouri — Natural Disaster Risk Assessment
HighComposite Risk Score
National percentile: 99th
St. Louis County faces high composite natural disaster risk (NRI Risk Index score 99.3, 99th national percentile), driven primarily by heat wave and hail exposure. Expected annual loss across all 18 hazard types is $753M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Top Hazards
All 18 Hazard Risks
| Heat Wave | Very High | 14.84 / yr | $253M |
| Hail | Very High | 5.26 / yr | $38M |
| Lightning | Very High | 52.97 / yr | $5M |
| Cold Wave | Very High | 1.74 / yr | $41M |
| Riverine Flood | High | 2.79 / yr | $240M |
| Earthquake | High | 0.01 / yr | $141M |
| Ice Storm | Very High | 1.41 / yr | $4M |
| Winter Weather | Very High | 8.74 / yr | $2M |
| Tornado | High | 0.41 / yr | $26M |
| Landslide | Medium | 0.97 / yr | $443K |
| Strong Wind | High | 5.93 / yr | $2M |
| Wildfire | Very Low | 0.00 / yr | $101K |
| Hurricane | Very Low | 0.01 / yr | $48K |
| Drought | Very Low | 1.86 / yr | $20K |
| 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. Louis County?
St. Louis County has a composite FEMA National Risk Index score of 99.3 out of 100, placing it in the High category and the 99th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in St. Louis County?
The three highest-rated hazards are Heat Wave (Very High, $253M EAL), Hail (Very High, $38M EAL), Lightning (Very High, $5M EAL). These account for most of the county's expected annual losses.
How does St. Louis County compare to other Missouri counties?
St. Louis County ranks #1 of 115 Missouri counties for overall natural disaster risk, with a high 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. Louis County's $753M EAL is a statistical average, not a guarantee for any specific year or address.