Harrison County
Mississippi — Natural Disaster Risk Assessment
HighComposite Risk Score
National percentile: 96th
Harrison County faces high composite natural disaster risk (NRI Risk Index score 95.6, 96th national percentile), driven primarily by hurricane and lightning exposure. Expected annual loss across all 18 hazard types is $155M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Top Hazards
All 18 Hazard Risks
| Hurricane | Very High | 0.24 / yr | $87M |
| Lightning | Very High | 87.00 / yr | $2M |
| Tornado | High | 0.75 / yr | $11M |
| Heat Wave | Medium | 13.72 / yr | $5M |
| Wildfire | Medium | 0.01 / yr | $3M |
| Coastal Flood | High | 6.48 / yr | $6M |
| Riverine Flood | Medium | 1.75 / yr | $33M |
| Cold Wave | Medium | 0.95 / yr | $5M |
| Hail | Medium | 1.92 / yr | $1M |
| Strong Wind | High | 1.60 / yr | $1M |
| Ice Storm | Medium | 0.58 / yr | $233K |
| Winter Weather | Medium | 0.84 / yr | $130K |
| Earthquake | Low | 0.00 / yr | $662K |
| Drought | Low | 18.70 / yr | $212K |
| Landslide | Very Low | 0.08 / yr | $317 |
| 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 Harrison County?
Harrison County has a composite FEMA National Risk Index score of 95.6 out of 100, placing it in the High category and the 96th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Harrison County?
The three highest-rated hazards are Hurricane (Very High, $87M EAL), Lightning (Very High, $2M EAL), Tornado (High, $11M EAL). These account for most of the county's expected annual losses.
How does Harrison County compare to other Mississippi counties?
Harrison County ranks #1 of 82 Mississippi 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. Harrison County's $155M EAL is a statistical average, not a guarantee for any specific year or address.