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FEMA NRI 1.19.0Updated Nov 2023 · Coverage 2014–2023Methodology

St. Mary Parish Disaster Risk

St. Mary Parish, Louisiana

FEMA Risk Rating

Relatively Moderate

National Percentile

89th

of 3,144 counties

State Rank

#14

of 64 (1 = highest risk)

Flood Risk

93th

percentile

Hazard Risk Breakdown

Flood

River, coastal, and surface flooding risk

Moderate

Higher than 93% of US counties

Wildfire

Wildland and wildland-urban interface fire risk

Very Low

Higher than 15% of US counties

Tornado

Tornado and severe thunderstorm risk

Moderate

Higher than 86% of US counties

Earthquake

Seismic activity and ground shaking risk

Relatively Low

Higher than 44% of US counties

Hurricane

Tropical cyclone and hurricane risk

Relatively High

Higher than 97% of US counties

Risk Overview

About Natural Disaster Risk in St. Mary Parish, Louisiana

St. Mary ranks among nation's riskier counties

With a composite risk score of 88.93, St. Mary Parish exceeds typical U.S. disaster risk significantly, earning a "Relatively Moderate" rating. The parish faces compounded hazards from water and wind that demand serious preparation.

42% above Louisiana's state average

St. Mary Parish scores 88.93 compared to Louisiana's 62.37 average, placing it in the state's upper tier of disaster-exposed parishes. This elevated profile reflects the parish's geographic position along Louisiana's coast and hurricane-prone zone.

Highest-risk parish in southern trio

St. Mary Parish edges slightly above St. Landry (88.20) and St. Martin (87.28) in composite risk, forming the state's most hazard-concentrated cluster. All three dramatically outpace lower-risk parishes like Union (49.65) and Tensas (14.50).

Hurricane and flood dominate risks

Hurricane risk peaks at 97.33—the highest threat facing the parish—while flood risk of 93.00 reflects coastal vulnerability and heavy rainfall patterns. Tornadoes also present significant danger at 86.36, creating a year-round hazard environment.

Comprehensive coverage is non-negotiable

St. Mary residents must obtain both standard homeowners insurance and separate flood insurance immediately, as the parish's 93.00 flood score demands dual protection. Ensure wind coverage explicitly includes hurricane-force conditions given the 97.33 hurricane threat.

Source: FEMA National Risk Index · Narrative reviewed by Evan Brooks, Data Editor

Preparedness Guide

What to Prepare for in St. Mary Parish

Top Hazards by Exposure

  1. #1
    HurricanePrepare
    97th percentile
  2. #2
    FloodPrepare
    93th percentile
  3. #3
    TornadoPrepare
    86th percentile

Source: FEMA National Risk Index v1.19.0 · Percentiles are national (3,144 counties)

Local Resources

Risk Advisory: St. Mary Parish

Risk Verdict

St. Mary Parish's overall risk score at the 89th percentile nationally signals meaningful exposure to multiple natural hazard types. Comprehensive household preparedness — including reviewing insurance, maintaining emergency supplies, and knowing evacuation routes — is strongly recommended.

Hazard Breakdown

Hurricane risk is St. Mary Parish's dominant natural hazard, ranked at the 97th percentile nationally under FEMA's National Risk Index. Flood ranks second at the 93th percentile nationally. Additional tracked hazards include tornado (86th percentile), earthquake (44th percentile), wildfire (15th percentile).

Preparedness Context

St. Mary Parish ranks at the 97th percentile nationally for hurricane risk. For coastal counties, wind-resistant shutters or impact-rated windows represent the highest single structural investment for reducing property damage. Flood, the county's second-ranked hazard at the 93th percentile nationally, represents an additional preparedness consideration for St. Mary Parish independent of hurricane season. For extended post-storm outages common in St. Mary Parish's hurricane zone, a portable generator (operated outdoors only) and a supply of non-perishable food for at least seven days provides meaningful household resilience.

Regional Context

Compared to other Louisiana counties, St. Mary Parish runs 26.6 composite risk points higher than the state mean — reflecting above-average hazard concentration in this area.

Is your household prepared for St. Mary Parish's hazards?

Review FEMA's county-specific preparedness checklists and emergency planning guides.

FEMA Ready Guide →

Frequently Asked Questions

What is the natural disaster risk in St. Mary Parish, LA?
St. Mary Parish has a FEMA National Risk Index rating of Relatively Moderate, placing it in the 89th percentile nationally out of 3,144 counties. This composite score reflects the county's overall exposure to natural hazards including floods, wildfires, tornadoes, earthquakes, and hurricanes, weighted by expected annual loss and social vulnerability.
What types of natural hazards affect St. Mary Parish?
St. Mary Parish is evaluated for five major natural hazard types: hurricane (97th percentile), flooding (93th percentile), tornado (86th percentile), earthquake (44th percentile), wildfire (15th percentile). The highest-risk hazard is hurricane at the 97th percentile nationally. These scores are derived from FEMA's National Risk Index, which analyzes expected annual loss, social vulnerability, and community resilience for each hazard type.
How does St. Mary Parish risk compare to the Louisiana average?
St. Mary Parish's composite risk percentile is 89th, compared to the Louisiana state average of 62th percentile. The state's overall risk rating is Relatively Low. This means St. Mary Parish faces higher natural disaster risk than the typical county in Louisiana.
Is St. Mary Parish at risk for hurricane?
Yes, St. Mary Parish's hurricane risk is at the 97th percentile nationally. This places it in the top quartile for this hazard type. For flooding specifically, St. Mary Parish is at the 93th percentile.
How is natural disaster risk measured?
FEMA's National Risk Index (NRI) calculates risk scores for 18 natural hazard types across all U.S. counties and census tracts. The composite score combines Expected Annual Loss (estimated dollar losses from each hazard), Social Vulnerability (demographic factors affecting disaster impact), and Community Resilience (ability to recover). Percentile scores rank each county against all 3,144 U.S. counties, and risk ratings range from Very Low to Very High.
Why is St. Mary Parish higher risk than average?
St. Mary Parish's composite risk score of 89th percentile is above the Louisiana state average of 62th percentile. This elevated risk is driven by hurricane exposure (97th percentile), along with flooding and tornado risk. Geographic location, terrain, climate patterns, and proximity to flood zones or fault lines all influence a county's risk profile.

Counties with Similar Risk

Acadia Parish

Louisiana

-0.3

Relatively Moderate

89th percentile

St. Landry Parish

Louisiana

-0.7

Relatively Moderate

88th percentile

Ouachita Parish

Louisiana

-1.4

Relatively Moderate

88th percentile

By Evan Brooks, Data EditorUpdated Reviewed by Evan Brooks, Data Editor

Data Source

Risk data sourced from the FEMA National Risk Index (NRI). Risk scores are relative rankings (0–100) across all US counties — not absolute risk measures. Higher scores indicate higher relative risk compared to other counties.

Disclaimer: This data is informational only. It is not financial, insurance, or legal advice. Always consult a qualified professional before making insurance or real estate decisions.

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