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

St. Mary's County Disaster Risk

St. Mary's County, Maryland

FEMA Risk Rating

Very Low

National Percentile

43th

of 3,144 counties

State Rank

#19

of 24 (1 = highest risk)

Flood Risk

63th

percentile

Hazard Risk Breakdown

Flood

River, coastal, and surface flooding risk

Relatively Low

Higher than 63% of US counties

Wildfire

Wildland and wildland-urban interface fire risk

Relatively Low

Higher than 59% of US counties

Tornado

Tornado and severe thunderstorm risk

Very Low

Higher than 39% of US counties

Earthquake

Seismic activity and ground shaking risk

Relatively Low

Higher than 57% of US counties

Hurricane

Tropical cyclone and hurricane risk

Moderate

Higher than 85% of US counties

Risk Overview

About Natural Disaster Risk in St. Mary's County, Maryland

St. Mary's maintains very low disaster risk

St. Mary's County's composite risk score of 42.56 sits comfortably below both the national average and Maryland's state average of 60.22. The county's 'very low' risk rating reflects moderate exposure across most hazard categories with no single threat reaching extreme levels.

Among Maryland's lowest-risk counties

St. Mary's County ranks among the safest counties in Maryland with a composite risk score of 42.56, significantly outperforming the state average. Only a few Maryland counties maintain comparably low overall disaster risk profiles.

Comparable risk to Talbot, lower than Somerset

St. Mary's County (42.56) closely matches Talbot County (42.37) in overall risk exposure, while remaining substantially safer than neighboring Somerset County (59.57) and Wicomico County (60.78). The southern Maryland location provides relative protection compared to higher-risk central and northern regions.

Hurricanes pose your greatest threat

Hurricane risk dominates St. Mary's hazard profile at 85.11, substantially higher than flood risk (63.00) or any other single threat. While your overall disaster risk remains very low, Atlantic hurricane season brings meaningful coastal wind and surge exposure despite your favorable comparative position.

Basic coverage with hurricane consideration

Your county's very low overall risk means standard homeowners insurance provides solid baseline protection for most hazards. However, ensure your policy includes robust wind damage coverage for hurricane season, and add flood insurance if your home sits in a coastal area or near significant water features.

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

Preparedness Guide

What to Prepare for in St. Mary's County

Top Hazards by Exposure

  1. #1
    HurricanePrepare
    85th percentile
  2. #2
    FloodPrepare
    63th percentile
  3. #3
    WildfirePrepare
    59th percentile

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

Risk Advisory: St. Mary's County

Risk Verdict

Natural disaster exposure in St. Mary's County is lower than roughly three-quarters of U.S. counties, with a composite score at the 43th percentile. At the 43th percentile, St. Mary's County's risk profile is among the more manageable in the country — the hazard-specific breakdown above shows where any remaining preparedness focus is best directed.

Hazard Breakdown

Hurricane risk is St. Mary's County's dominant natural hazard, ranked at the 85th percentile nationally under FEMA's National Risk Index. Flood ranks second at the 63th percentile nationally. Additional tracked hazards include wildfire (59th percentile), earthquake (57th percentile), tornado (39th percentile).

Preparedness Context

At the 85th percentile nationally for hurricane risk, St. Mary's County is in a zone where flood insurance matters beyond the primary wind risk: NFIP flood insurance requires a 30-day waiting period before taking effect, making off-season enrollment the correct timing. St. Mary's County's flood exposure at the 63th percentile nationally adds a hazard layer that can persist or intensify after hurricane-force winds have passed, particularly in low-lying inland areas. For St. Mary's County households, the hurricane preparedness calendar matters: flood insurance has a 30-day waiting period, wind-hardening retrofits take weeks to schedule, and evacuation route scouting is best done before a storm watch is issued.

Regional Context

St. Mary's County is 17.7 composite risk points below the Maryland state mean, meaning most other Maryland counties face higher natural hazard exposure.

Is your household prepared for St. Mary's County'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's County, MD?
St. Mary's County has a FEMA National Risk Index rating of Very Low, placing it in the 43th 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's County?
St. Mary's County is evaluated for five major natural hazard types: hurricane (85th percentile), flooding (63th percentile), wildfire (59th percentile), earthquake (57th percentile), tornado (39th percentile). The highest-risk hazard is hurricane at the 85th 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's County risk compare to the Maryland average?
St. Mary's County's composite risk percentile is 43th, compared to the Maryland state average of 60th percentile. The state's overall risk rating is Relatively Low. This means St. Mary's County faces lower natural disaster risk than the typical county in Maryland.
Is St. Mary's County at risk for hurricane?
Yes, St. Mary's County's hurricane risk is at the 85th percentile nationally. This places it in the top quartile for this hazard type. For flooding specifically, St. Mary's County is at the 63th 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.
Is St. Mary's County a safe place to live?
St. Mary's County's composite risk score of 43th percentile is below the Maryland state average of 60th percentile, indicating relatively lower exposure to natural hazards. However, no county is completely risk-free. The primary hazard type is hurricane at the 85th percentile. Residents should still maintain emergency preparedness plans and appropriate insurance coverage.
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.