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

Suffolk County Disaster Risk

Suffolk County, Massachusetts

FEMA Risk Rating

Relatively Moderate

National Percentile

94th

of 3,144 counties

State Rank

#4

of 14 (1 = highest risk)

Flood Risk

95th

percentile

Hazard Risk Breakdown

Flood

River, coastal, and surface flooding risk

Relatively High

Higher than 95% of US counties

Wildfire

Wildland and wildland-urban interface fire risk

Very Low

Higher than 9% of US counties

Tornado

Tornado and severe thunderstorm risk

Relatively Low

Higher than 75% of US counties

Earthquake

Seismic activity and ground shaking risk

Relatively High

Higher than 95% of US counties

Hurricane

Tropical cyclone and hurricane risk

Moderate

Higher than 94% of US counties

Risk Overview

About Natural Disaster Risk in Suffolk County, Massachusetts

Suffolk faces notably elevated disaster risk

Suffolk County scores 93.51 on composite risk, placing it in the relatively moderate category—well above the national average. This score reflects substantial urban and coastal exposure across multiple hazard categories, with minimal wildfire risk offsetting other concerns.

Third-highest risk county in Massachusetts

Suffolk ranks third-riskiest in Massachusetts, with a composite score of 93.51 compared to the state average of 78.84. The county's 19% elevation above the state baseline reflects concentrated vulnerability in densely populated Boston and surrounding areas.

Among the state's most vulnerable counties

Suffolk's 93.51 score exceeds regional peers Plymouth (90.36) and trails only Middlesex (96.95) and Worcester (93.54). The county's urban concentration amplifies earthquake risk (94.97) and tornado risk (75.35) compared to more rural neighbors.

Earthquakes and floods are critical threats

Earthquake risk peaks at 94.97, while flood risk reaches 94.72—both among Massachusetts's highest, driven by dense development and coastal exposure. Hurricane risk (93.66) and tornado risk (75.35) round out Suffolk's profile; wildfire risk remains negligible at 8.97.

Earthquake and flood coverage are essential

Boston and inner suburbs face exceptional earthquake risk (94.97), requiring dedicated earthquake insurance beyond standard policies. Flood coverage is equally critical given your county's 94.72 flood risk; bundling both with your homeowners policy provides comprehensive protection for Suffolk's primary hazards.

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

Preparedness Guide

What to Prepare for in Suffolk County

Top Hazards by Exposure

  1. #1
    EarthquakePrepare
    95th percentile
  2. #2
    FloodPrepare
    95th percentile
  3. #3
    HurricanePrepare
    94th percentile

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

Local Resources

Risk Advisory: Suffolk County

Risk Verdict

Suffolk County faces a moderate natural disaster risk profile, ranking at the 94th percentile nationally under FEMA's composite risk model. This risk level calls for more than general awareness: insurance coverage review, a family communication plan, and a prepared go-bag are practical priorities.

Hazard Breakdown

Earthquake risk is Suffolk County's dominant natural hazard, ranked at the 95th percentile nationally under FEMA's National Risk Index. Flood ranks second at the 95th percentile nationally. Additional tracked hazards include hurricane (94th percentile), tornado (75th percentile), wildfire (9th percentile).

Preparedness Context

Earthquake risk is Suffolk County's leading natural hazard, ranked at the 95th percentile nationally. Securing tall furniture, water heaters, and bookcases to walls with anti-tip hardware is among the simplest and most effective life-safety measures households can take. Flood at the 95th percentile nationally is a separate hazard dimension for Suffolk County that requires different protective strategies from earthquake preparedness. Suffolk County residents should locate the main gas shutoff valve and keep an appropriate wrench nearby — gas leaks cause a significant share of earthquake-related injuries and fires, and the shutoff step is safe to take immediately after shaking stops.

Regional Context

Suffolk County's composite risk score sits 14.7 points above the Massachusetts county average, placing it among the more hazard-exposed counties in the state.

Is your household prepared for Suffolk 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 Suffolk County, MA?
Suffolk County has a FEMA National Risk Index rating of Relatively Moderate, placing it in the 94th 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 Suffolk County?
Suffolk County is evaluated for five major natural hazard types: earthquake (95th percentile), flooding (95th percentile), hurricane (94th percentile), tornado (75th percentile), wildfire (9th percentile). The highest-risk hazard is earthquake at the 95th 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 Suffolk County risk compare to the Massachusetts average?
Suffolk County's composite risk percentile is 94th, compared to the Massachusetts state average of 79th percentile. The state's overall risk rating is Relatively Low. This means Suffolk County faces higher natural disaster risk than the typical county in Massachusetts.
Is Suffolk County at risk for earthquake?
Yes, Suffolk County's earthquake risk is at the 95th percentile nationally. This places it in the top quartile for this hazard type. For flooding specifically, Suffolk County is at the 95th 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 Suffolk County higher risk than average?
Suffolk County's composite risk score of 94th percentile is above the Massachusetts state average of 79th percentile. This elevated risk is driven by earthquake exposure (95th percentile), along with flooding and hurricane 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

Worcester County

Massachusetts

+0.0

Relatively Moderate

94th percentile

Hampden County

Massachusetts

-0.7

Relatively Moderate

93th percentile

Norfolk County

Massachusetts

-1.5

Relatively Moderate

92th 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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