St. Tammany Parish
Louisiana — Natural Disaster Risk Assessment
HighComposite Risk Score
National percentile: 97th
St. Tammany Parish faces high composite natural disaster risk (NRI Risk Index score 96.6, 97th national percentile), driven primarily by hurricane and heat wave exposure. Expected annual loss across all 18 hazard types is $249M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Top Hazards
All 18 Hazard Risks
| Hurricane | Very High | 0.23 / yr | $143M |
| Heat Wave | Medium | 16.11 / yr | $8M |
| Lightning | High | 84.65 / yr | $2M |
| Riverine Flood | High | 2.32 / yr | $70M |
| Cold Wave | High | 1.09 / yr | $9M |
| Wildfire | Medium | 0.00 / yr | $1M |
| Hail | Medium | 1.95 / yr | $2M |
| Tornado | Medium | 1.03 / yr | $6M |
| Coastal Flood | High | 3.70 / yr | $3M |
| Strong Wind | Medium | 1.61 / yr | $1M |
| Drought | Medium | 18.53 / yr | $988K |
| Winter Weather | Medium | 1.07 / yr | $208K |
| Ice Storm | Medium | 0.53 / yr | $370K |
| Earthquake | Low | 0.00 / yr | $724K |
| Landslide | Very Low | 0.12 / yr | $596 |
| 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 St. Tammany Parish?
St. Tammany Parish has a composite FEMA National Risk Index score of 96.6 out of 100, placing it in the High category and the 97th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in St. Tammany Parish?
The three highest-rated hazards are Hurricane (Very High, $143M EAL), Heat Wave (Medium, $8M EAL), Lightning (High, $2M EAL). These account for most of the county's expected annual losses.
How does St. Tammany Parish compare to other Louisiana counties?
St. Tammany Parish ranks #4 of 64 Louisiana 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. Tammany Parish's $249M EAL is a statistical average, not a guarantee for any specific year or address.