St. Mary Parish, Louisiana: Natural Disaster Risk and History
St. Mary Parish, Louisiana has a Relatively Moderate natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 88.9 out of 100, higher than about 88% of US counties, with hurricanes, coastal flooding and drought scoring highest of its 18 hazards and $61 million a year in expected losses.
OpenFEMA lists 47 federal disaster declarations that included St. Mary Parish since 1965, not counting 2 for COVID-19; the latest is EM-3638-LA (Severe Winter Storm, declared 24 January 2026). NOAA's Storm Prediction Center recorded 24 tornadoes touching St. Mary Parish from 1950 to 2025.
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Population 49,313 Buildings worth $13 billion Area 1,131 sq mi Risk rank in Louisiana 14 of 64 FIPS 22101
All 18 hazards, highest risk first
FEMA National Risk Index| Hazard | Risk rating | Score | Expected loss a year | How often | Events in record |
|---|---|---|---|---|---|
| Hurricane | Relatively High | 97.3 | $39 million | about once every 4.4 years | 83 |
| Coastal flooding | Relatively High | 93.0 | $6.5 million | about 3.8 a year | — |
| Drought | Relatively High | 91.1 | $1.4 million | about 24 a year | 735 |
| Tornado | Relatively Moderate | 86.4 | $4.4 million | about once every 1.7 years | 17 |
| Cold wave | Relatively Moderate | 76.7 | $2.3 million | about once every 1.1 years | 15 |
| Heat wave | Relatively Low | 74.9 | $897,858 | about 9.4 a year | 121 |
| Lightning | Relatively Moderate | 66.7 | $343,100 | about 88 a year | 245,434 strikes |
| Inland flooding | Relatively Low | 50.1 | $5.3 million | about once every 1.1 years | 25 |
| Strong wind | Relatively Low | 46.5 | $388,525 | about once every 1.5 years | 21 |
| Earthquake | Very Low | 43.7 | $150,184 | rarer than once in 1,000 years | — |
| Hail | Relatively Low | 42.8 | $155,207 | about once every 1.1 years | 48 |
| Winter weather | Relatively Low | 35.6 | $29,351 | about once every 1.4 years | 9.3 |
| Ice storm | Relatively Low | 32.5 | $29,083 | about once every 8.2 years | 6 |
| Landslide | Very Low | 17.1 | $63 | about once every 16 years | — |
| Wildfire | Very Low | 15.0 | $3,962 | rarer than once in 1,000 years | — |
| Avalanche | Not Applicable | — | — | — | — |
| Tsunami | Insufficient Data | — | — | — | — |
| Volcanic activity | Not Applicable | — | — | — | — |
Score: FEMA's percentile among US counties that face the hazard (higher = more risk). Expected loss: FEMA's modelled average yearly loss to buildings, people (as a statistical value) and crops. How often: FEMA's annualised frequency of the hazard in the county; for some hazards it counts event-days, so it is a rough guide, not a forecast. "Not Applicable" means FEMA does not model that hazard here.
Federal disaster declarations 47
Most common: Hurricane 30, Flood 7, Coastal Storm 4, Other 2.
| Decade | Declarations | Incident types |
|---|---|---|
| 1960s | 1 | Hurricane |
| 1970s | 3 | Hurricane ×2, Flood |
| 1980s | 1 | Flood |
| 1990s | 3 | Hurricane ×2, Severe Storm |
| 2000s | 11 | Hurricane ×9, Other, Coastal Storm |
| 2010s | 11 | Flood ×5, Hurricane ×5, Coastal Storm |
| 2020s | 17 | Hurricane ×11, Coastal Storm ×2, Severe Ice Storm ×2, Winter Storm, Other |
The last 10
Widest declarations that included St. Mary Parish
- Severe Winter Storm (2026, EM-3638-LA): 64 Louisiana counties designated.
- Tropical Storm Francine (2024, EM-3614-LA): 64 Louisiana counties designated.
- Tropical Storm Nicholas (2021, EM-3574-LA): 64 Louisiana counties designated.
Named storms in its declarations: Hurricane Francine (2024), Tropical Storm Francine (2024), Tropical Storm Nicholas (2021), Hurricane Ida (2021), Tropical Storm Ida (2021), Hurricane Zeta (2021), Tropical Storm Zeta (2020), Hurricane Delta (2020), Hurricane Sally (2020), Hurricane Laura (2020), Tropical Storm Cristobal (2020), Hurricane Barry (2019), Tropical Storm Barry (2019), Tropical Storm Harvey (2017), Tropical Storm Nate (2017), Hurricane Isaac (2012), Tropical Storm Isaac (2012), Hurricane Ike (2008), Hurricane Gustav (2008), Hurricane Rita (2005), Hurricane Katrina (2005), Hurricane Lili (2002), Tropical Storm Isidore (2002), Tropical Storm Allison (2001), Hurricane Georges (1998), Hurricane Andrew (1992), Hurricane Carmen (1974), Hurricane Edith (1971), Hurricane Betsy (1965).
Not counted above: 2 COVID-19 ("Biological") declarations — in 2020 every US county was included. Louisiana also had 6 statewide declarations with no county list.
Tornado record since 1950 24
| Tornadoes touching the county | 24 |
|---|---|
| Strongest-rated | (E)F3 ×1 |
| Peak month | September (5) |
| Deadliest | 10 Sep 1961, F2, 1 mi path, 0 killed, 16 injured |
| Longest path | 4 Apr 1952, F2, 6.4 mi path, 0 killed, 3 injured |
| Most recent | 14 Apr 2018, EF0, 0.3 mi path |
| Deaths / injuries on those paths | 0 / 26 |
| Rating | (E)F0 | (E)F1 | (E)F2 | (E)F3 | (E)F4 | (E)F5 | Unrated |
|---|---|---|---|---|---|---|---|
| Count | 8 | 12 | 3 | 1 | 0 | 0 | 0 |
| Decade | 1950s | 1960s | 1970s | 1980s | 1990s | 2000s | 2010s | 2020s |
|---|---|---|---|---|---|---|---|---|
| Count | 1 | 2 | 5 | 3 | 5 | 1 | 7 | 0 |
Deaths and injuries are for each tornado's whole path, which can run beyond this county. F-scale ratings before February 2007, Enhanced Fujita (EF) after.
How St. Mary Parish compares with its 5 nearest counties
| County | Distance | Overall risk | Score | Top hazard |
|---|---|---|---|---|
| St. Mary Parish (this page) | — | Relatively Moderate | 88.9 | Hurricane |
| Iberia Parish | 33 km | Relatively Moderate | 90.6 | Hurricane |
| Assumption Parish | 43 km | Relatively Low | 70.3 | Drought |
| St. Martin Parish | 48 km | Relatively Moderate | 87.3 | Hurricane |
| Iberville Parish | 60 km | Relatively Low | 73.7 | Hurricane |
| Terrebonne Parish | 66 km | Relatively Moderate | 94.2 | Hurricane |
Nearest by distance between county centres. Every county in Louisiana, ranked.
Vulnerability and resilience
| Social vulnerability | Relatively High 75.6 |
|---|---|
| Community resilience | Very High 88.2 |
| Community risk factor | 1.33 |
| Expected annual loss, all hazards | $61 million |
FEMA scales expected losses up where social vulnerability is high (people who may find it harder to prepare, evacuate or recover) and down where community resilience is high. A factor above 1 raises the risk score. For social vulnerability a high rating is worse; for resilience a high rating is better.
Prepare for St. Mary Parish's main hazards
- Right now: National Weather Service alerts for Louisiana · all official warnings on Global Incident Tracker.
- Hurricane: Is there a hurricane now? · Cyclone preparation
- Coastal flooding: Flood safety: why shallow water kills · Hurricanes and storms now
- Drought: Drought monitor for Louisiana
- Your property's flood zone: FEMA Flood Map Service Center ↗ — this page cannot tell you that.
- Official preparedness guidance: Ready.gov ↗ and your county emergency management office.
What this page shows, and what it misses
FEMA's National Risk Index rates a whole county against every other US county; it is a planning-level estimate for nationwide comparison, not a flood-zone map and not a substitute for a local risk assessment or the risk to one home. Declarations are presidential disaster, emergency and fire management declarations that named this county; state declarations and SBA or USDA designations are not included. Tornadoes are counted when the county is one of up to four listed on the track; 670 tornadoes that crossed a state line carry no county list in NOAA's file and are left out.
Federal Emergency Management Agency (FEMA), National Risk Index Dataset: National Risk Index Counties - v1.20.0 (December 2025). Retrieved from https://services.arcgis.com/XG15cJAlne2vxtgt/ArcGIS/rest/services/National_Risk_Index_Counties/FeatureServer/0/query on November 2, 2026, 1:20 PM EST. This product uses the Federal Emergency Management Agency’s National Risk Index dataset API or downloadable datasets but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).
Federal Emergency Management Agency (FEMA), OpenFEMA Dataset: Disaster Declarations Summaries - v2, retrieved from https://www.fema.gov/api/open/v2/DisasterDeclarationsSummaries on November 2, 2026, 1:21 PM EST. This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).
Tornado records: NOAA/NWS Storm Prediction Center, Severe Weather Database, tornadoes 1950–2025 (https://www.spc.noaa.gov/wcm/data/1950-2025_actual_tornadoes.csv, downloaded 2 November 2026). Public domain; not endorsed by NOAA. Compiled by Global Incident Tracker.
Questions about St. Mary Parish
What natural disasters is St. Mary Parish, Louisiana most at risk from?
St. Mary Parish, Louisiana has a Relatively Moderate natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 88.9 out of 100, higher than about 88% of US counties, with hurricanes, coastal flooding and drought scoring highest of its 18 hazards and $61 million a year in expected losses.
How many federal disaster declarations has St. Mary Parish had?
OpenFEMA lists 47 federal disaster declarations that included St. Mary Parish since 1965, not counting 2 for COVID-19; the latest is EM-3638-LA (Severe Winter Storm, declared 24 January 2026). Another 6 Louisiana declarations were made statewide without a county list.
How many tornadoes have hit St. Mary Parish?
NOAA's Storm Prediction Center recorded 24 tornadoes touching St. Mary Parish from 1950 to 2025. The deadliest: 10 Sep 1961, F2, 1 mi path, 0 killed, 16 injured (deaths and injuries are for the whole path).
Is the National Risk Index a flood zone map?
No. The National Risk Index is a planning-level estimate for a whole county, built for nationwide comparison. It does not tell you the flood zone or the risk of a single property: for that, look up the address on FEMA's Flood Map Service Center (msc.fema.gov) and ask your local floodplain manager.