St. Clair County
Michigan — Natural Disaster Risk Assessment
MediumComposite Risk Score
National percentile: 82th
St. Clair County faces medium composite natural disaster risk (NRI Risk Index score 82.0, 82th national percentile), driven primarily by cold wave and tornado exposure. Expected annual loss across all 18 hazard types is $49M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Top Hazards
All 18 Hazard Risks
| Cold Wave | High | 3.00 / yr | $10M |
| Tornado | Medium | 0.21 / yr | $6M |
| Ice Storm | High | 1.90 / yr | $705K |
| Riverine Flood | Medium | 1.04 / yr | $29M |
| Strong Wind | High | 3.52 / yr | $2M |
| Heat Wave | Low | 2.37 / yr | $733K |
| Winter Weather | Low | 12.89 / yr | $88K |
| Earthquake | Very Low | 0.00 / yr | $305K |
| Hail | Low | 1.66 / yr | $256K |
| Coastal Flood | Low | 0.01 / yr | $57K |
| Lightning | Low | 32.26 / yr | $199K |
| Landslide | Very Low | 0.10 / yr | $589 |
| Hurricane | Very Low | 0.02 / yr | $24K |
| Wildfire | Very Low | 0.00 / yr | $19K |
| Avalanche | Very Low | 0.00 / yr | $0 |
| Drought | 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. Clair County?
St. Clair County has a composite FEMA National Risk Index score of 82.0 out of 100, placing it in the Medium category and the 82th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in St. Clair County?
The three highest-rated hazards are Cold Wave (High, $10M EAL), Tornado (Medium, $6M EAL), Ice Storm (High, $705K EAL). These account for most of the county's expected annual losses.
How does St. Clair County compare to other Michigan counties?
St. Clair County ranks #11 of 83 Michigan 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. Clair County's $49M EAL is a statistical average, not a guarantee for any specific year or address.