Dorchester County
South Carolina — Natural Disaster Risk Assessment
MediumComposite Risk Score
National percentile: 94th
Dorchester County faces medium composite natural disaster risk (NRI Risk Index score 93.7, 94th national percentile), driven primarily by earthquake and hurricane exposure. Expected annual loss across all 18 hazard types is $176M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Top Hazards
All 18 Hazard Risks
| Earthquake | Medium | 0.01 / yr | $58M |
| Hurricane | High | 0.31 / yr | $84M |
| Ice Storm | High | 1.09 / yr | $658K |
| Lightning | High | 66.11 / yr | $1M |
| Wildfire | Low | 0.00 / yr | $454K |
| Riverine Flood | Medium | 1.39 / yr | $23M |
| Tornado | Medium | 0.32 / yr | $4M |
| Heat Wave | Low | 8.91 / yr | $1M |
| Winter Weather | Medium | 1.05 / yr | $149K |
| Cold Wave | Medium | 0.69 / yr | $2M |
| Coastal Flood | Low | 3.50 / yr | $542K |
| Hail | Low | 3.05 / yr | $273K |
| Drought | Very Low | 15.41 / yr | $22K |
| Strong Wind | Low | 3.21 / yr | $204K |
| Landslide | Very Low | 0.16 / yr | $66 |
| Avalanche | 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 Dorchester County?
Dorchester County has a composite FEMA National Risk Index score of 93.7 out of 100, placing it in the Medium category and the 94th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Dorchester County?
The three highest-rated hazards are Earthquake (Medium, $58M EAL), Hurricane (High, $84M EAL), Ice Storm (High, $658K EAL). These account for most of the county's expected annual losses.
How does Dorchester County compare to other South Carolina counties?
Dorchester County ranks #6 of 46 South Carolina 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. Dorchester County's $176M EAL is a statistical average, not a guarantee for any specific year or address.