St. Mary Parish, Louisiana Natural Disaster Risk
FEMA National Risk Index assessment · LA
MediumComposite Risk Score
National percentile: 89th
St. Mary Parish faces medium composite natural disaster risk (NRI Risk Index score 88.9, 89th national percentile), driven primarily by hurricane and coastal flood exposure. Expected annual loss across all 18 hazard types is $61M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
St. Mary Parish carries a medium composite natural disaster risk, with a National Risk Index score of 88.9 out of 100 — placing it in the 89th national percentile and near the national midpoint for natural-disaster risk. The score blends Expected Annual Loss, Social Vulnerability, and Community Resilience across all 18 FEMA hazard types.
Most of St. Mary Parish's expected losses come from hurricane (tropical cyclones bringing extreme wind, rain, and storm surge) at High risk — $39M in expected annual loss and about 0.23 events per year; coastal flood (seawater inundation from storm surge, high tides, and rising sea levels) at High risk — $6M in expected annual loss and about 3.83 events per year; and drought (extended dry periods that stress water supplies and agriculture) at High risk — $1M in expected annual loss and about 24.36 events per year. Across all hazards, FEMA estimates $61M in expected annual loss for a population of 49K.
Beyond physical exposure, St. Mary Parish has a high social vulnerability rating (how susceptible the population is to harm) and a very high community resilience rating (its capacity to prepare for and recover from disasters). Higher vulnerability is partly offset by strong community resilience and recovery capacity.
The county's disaster history tells the same story: St. Mary Parish has received 49 federal disaster declarations since 1965, including 30 for hurricane events and 7 for flood events. The most recent was Severe Winter Storm (winter storm), declared in January 2026.
Among 64 Louisiana counties, St. Mary Parish ranks #14 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Hurricane | High | 0.23 / yr | $39M |
| Coastal Flood | High | 3.83 / yr | $6M |
| Drought | High | 24.36 / yr | $1M |
| Tornado | Medium | 0.59 / yr | $4M |
| Cold Wave | Medium | 0.92 / yr | $2M |
| Heat Wave | Low | 9.44 / yr | $898K |
| Lightning | Medium | 88.17 / yr | $343K |
| Riverine Flood | Low | 0.89 / yr | $5M |
| Strong Wind | Low | 0.66 / yr | $389K |
| Earthquake | Very Low | 0.00 / yr | $150K |
| Hail | Low | 0.92 / yr | $155K |
| Winter Weather | Low | 0.69 / yr | $29K |
| Ice Storm | Low | 0.12 / yr | $29K |
| Landslide | Very Low | 0.06 / yr | $63 |
| Wildfire | Very Low | 0.00 / yr | $4K |
| Avalanche | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
| Volcanic Activity | Very Low | 0.00 / yr | $0 |
Disaster History
St. Mary Parish has received 49 federal disaster declarations since 1965, most recently Severe Winter Storm in January 2026. Most frequent causes: Hurricane (30), Flood (7), Coastal Storm (4).
| Declared | Type | Disaster |
|---|---|---|
| January 2026 | Winter Storm | Severe Winter Storm |
| September 2024 | Hurricane | Hurricane Francine |
| September 2024 | Hurricane | Tropical Storm Francine |
| September 2023 | Other | Seawater Intrusion |
| September 2021 | Coastal Storm | Tropical Storm Nicholas |
| August 2021 | Hurricane | Hurricane Ida |
| August 2021 | Hurricane | Tropical Storm Ida |
| March 2021 | Severe Ice Storm | Severe Winter Storms |
| February 2021 | Severe Ice Storm | Severe Winter Storm |
| January 2021 | Hurricane | Hurricane Zeta |
Showing the 10 most recent of 49 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for St. Mary Parish?
St. Mary Parish has a composite FEMA National Risk Index score of 88.9 out of 100, placing it in the Medium category and the 89th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in St. Mary Parish?
The three highest-rated hazards are Hurricane (High, $39M EAL), Coastal Flood (High, $6M EAL), Drought (High, $1M EAL). These account for most of the county's expected annual losses.
How does St. Mary Parish compare to other Louisiana counties?
St. Mary Parish ranks #14 of 64 Louisiana counties for overall natural disaster risk, with a medium rating.
How many federally declared disasters has St. Mary Parish had?
FEMA records 49 federal disaster declarations for St. Mary Parish since 1965, most often 30 for hurricane events and 7 for flood events. The most recent was Severe Winter Storm, declared in January 2026.
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. Mary Parish's $61M EAL is a statistical average, not a guarantee for any specific year or address.