St. Mary Parish, Louisiana

What hazards hit St. Mary Parish most?

The most frequent records are severe thunderstorm wind events: 88 since 1969. The rank column places the county among Louisiana's counties by days with a record per 1,000 square miles of land over each hazard's complete period.

Source: NOAA NCEI Storm Events Database (county and forecast-zone records attributed to the county; a zone record shows its own totals on each county it covers). Days: dates with at least one record of the hazard in the county. Ranks: days with a record per 1,000 square miles of land (Census Bureau 2024 Gazetteer), since 1950 for tornadoes, 1955 for hail and thunderstorm wind, 1996 for the rest.

How many tornadoes has St. Mary Parish had?

NOAA records 24 tornadoes in St. Mary Parish from 1952 to 2018, the strongest rated F3, with 0 deaths and 26 injuries recorded in the county. A tornado that crossed a county line is counted in each county it touched, with the length of its path inside the county.

Counted as whole tornadoes rather than county records, the Storm Prediction Center's database holds 24 tornadoes whose track touched St. Mary Parish since 1950 (NOAA's county records number 24, the same count); along their whole tracks they killed 0 people.

Map of the strongest tornado tracks in Louisiana.

Source: NOAA NCEI Storm Events Database, tornado records by county (path length in the county, maximum width); ratings as published: F scale before February 1, 2007, EF scale after. Whole-track figures: NOAA Storm Prediction Center tornado database (1950-2025). SPC severe weather database.

When was the last damaging storm in St. Mary Parish?

The most recent record with damage, injuries or deaths is the July 30, 2025 lightning ($200,000 in damage in 2025 dollars).

Source: NOAA NCEI Storm Events Database; every record of 2025-2026 is listed, earlier ones when they caused deaths, injuries or $250,000 of damage (2025 dollars), and every tornado.

The deadliest and costliest records

A damage figure marked "step" is a record from before 1993: NOAA then filed damage by category, and the figure is the category as entered, in the dollars of that year, not an estimate of the loss.

Source: NOAA NCEI Storm Events Database: deaths and injuries direct and indirect; damage is property plus crops as estimated by the National Weather Service, converted to 2025 dollars.

Is it getting more frequent?

Records per decade for St. Mary Parish's most frequent hazards. Counts rose everywhere after 1996, when NOAA began recording every event type, so compare decades within a hazard's complete period only (the shaded cells come before it).

Source: NOAA NCEI Storm Events Database, records per calendar decade; zone records from the CZ_TYPE field (Z).

What time of year?

Records by month in St. Mary Parish. The two busiest months are in violet.

Source: NOAA NCEI Storm Events Database, records by the month they began.

Federal disaster declarations for St. Mary Parish

FEMA's register lists 49 declarations that include St. Mary Parish: 27 major disasters, 22 emergencies and 0 fire management assistance declarations. Most were for hurricane (30) and flood (7).

The 40 most recent of 49 are listed; the CSV has every one.

Source: FEMA OpenFEMA Disaster Declarations Summaries (v2), declarations through October 2, 2026; one declaration is counted once however many areas it names. OpenFEMA dataset page.

How many floods has St. Mary Parish had?

NOAA's Storm Events Database holds 39 flood or flash flood records for St. Mary Parish from 1996 to 2024, on 37 days, with 0 deaths. By flood insurance claims since 1978 (OpenFEMA, as of September 8, 2026), St. Mary Parish ranks 154th of 2,942 U.S. counties.

The National Flood Insurance Program has paid $37.3 million on 2,532 claims filed in St. Mary Parish; the most in one year was 331 in 2008. Claims count insured losses only: uninsured flood damage is not in this file.

Source: FEMA OpenFEMA NFIP Redacted Claims, as of September 8, 2026; claims by year of loss, payments in the dollars of the year paid. OpenFEMA dataset page.

FEMA's modeled risk for St. Mary Parish

FEMA's National Risk Index rates St. Mary Parish Relatively Moderate overall, with an expected annual loss of $60.7 million. These are FEMA's model estimates of future loss from 18 hazards, not a count of what happened; they can differ from the record above.

Source: FEMA National Risk Index, county table, December 2025 release. FEMA's National Risk Index map.

Counties that share a border with St. Mary Parish

1. Terrebonne Parish 442
2. Iberia Parish 297
3. St. Mary Parish 281
4. St. Martin Parish 239
5. Assumption Parish 164

Source: U.S. Census Bureau county adjacency file; NOAA NCEI Storm Events Database, records since 1950. The Census Bureau's adjacency file.

Next

• Tornadoes in LouisianaEvery Louisiana tornado since 1950 and the counties with the most per square mile
• Severe thunderstorm wind in LouisianaThe state's severe thunderstorm wind events, by county, year and month
• The Louisiana recordEvery hazard in the state, its deadliest events and its federal declarations
• FEMA's risk rating for each hazard in St. Mary ParishThe hazard risk calculator: 18 hazards beside the county's record
• Download St. Mary Parish's FEMA declarations (CSV)49 rows: every declaration that named the county, for your own analysis