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

Norfolk County Disaster Risk

Norfolk County, Massachusetts

FEMA Risk Rating

Relatively Moderate

National Percentile

92th

of 3,144 counties

State Rank

#6

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

Relatively Low

Higher than 50% of US counties

Tornado

Tornado and severe thunderstorm risk

Relatively Low

Higher than 69% of US counties

Earthquake

Seismic activity and ground shaking risk

Moderate

Higher than 92% of US counties

Hurricane

Tropical cyclone and hurricane risk

Moderate

Higher than 92% of US counties

Risk Overview

About Natural Disaster Risk in Norfolk County, Massachusetts

Norfolk carries moderately high disaster risk

Norfolk County scores 92.02 on composite risk, placing it in the relatively moderate category—above the national average. This score reflects substantial exposure to multiple hazards concentrated along the county's heavily populated coastal and urban areas.

Second-highest risk county in Massachusetts

Norfolk ranks second-riskiest in Massachusetts after Middlesex, with a composite score of 92.02 compared to the state average of 78.84. The county's 17% elevation above state average reflects particularly acute flood and earthquake vulnerabilities.

Riskier than Plymouth, safer than Middlesex

Norfolk's 92.02 score exceeds Plymouth County (90.36) but trails the state's highest-risk county, Middlesex (96.95). The county's flood risk (95.45) is comparable to regional peers, while its tornado risk (68.96) is among the lowest in its cluster.

Floods and earthquakes dominate your risks

Flood risk leads at 95.45, while earthquake risk reaches 91.51—both among Massachusetts's highest. Hurricane risk (92.20) and tornado risk (68.96) complete Norfolk's hazard portfolio, though less severe than some regional neighbors.

Bundle flood and earthquake insurance today

Standard homeowners policies exclude flood and earthquake coverage, both critical in Norfolk given your county's vulnerability. Securing separate flood and earthquake policies now protects your home's most significant risk exposures while rates remain manageable.

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

Preparedness Guide

What to Prepare for in Norfolk County

Top Hazards by Exposure

  1. #1
    FloodPrepare
    95th percentile
  2. #2
    HurricanePrepare
    92th percentile
  3. #3
    EarthquakePrepare
    92th percentile

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

Risk Advisory: Norfolk County

Risk Verdict

FEMA's National Risk Index rates Norfolk County at the 92th percentile nationally — above average and worth proactive preparation. Residents should prioritize a formal household emergency plan, including evacuation routes, insurance review, and a well-stocked emergency kit.

Hazard Breakdown

Flood risk is Norfolk County's dominant natural hazard, ranked at the 95th percentile nationally under FEMA's National Risk Index. Hurricane ranks second at the 92th percentile nationally. Additional tracked hazards include earthquake (92th percentile), tornado (69th percentile), wildfire (50th percentile).

Preparedness Context

Flood risk is Norfolk County's top hazard at the 95th percentile nationally. Households in or near designated flood zones face elevated financial exposure; flood insurance typically requires a 30-day waiting period before it takes effect, so applying before the season is advisable. The county's second-ranked hazard, hurricane at the 92th percentile nationally, means Norfolk County residents face compounding risks from multiple natural hazard types during peak seasons. Households across Norfolk County should identify the nearest community shelter and keep a basic emergency kit — water, non-perishable food, medications, flashlight, and battery radio — in a location easy to grab quickly.

Regional Context

Norfolk County is 13.2 composite risk points above the Massachusetts average, indicating that residents face greater natural hazard exposure than most of their in-state neighbors.

Is your household prepared for Norfolk 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 Norfolk County, MA?
Norfolk County has a FEMA National Risk Index rating of Relatively Moderate, placing it in the 92th 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 Norfolk County?
Norfolk County is evaluated for five major natural hazard types: flooding (95th percentile), hurricane (92th percentile), earthquake (92th percentile), tornado (69th percentile), wildfire (50th percentile). The highest-risk hazard is flooding 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 Norfolk County risk compare to the Massachusetts average?
Norfolk County's composite risk percentile is 92th, compared to the Massachusetts state average of 79th percentile. The state's overall risk rating is Relatively Low. This means Norfolk County faces higher natural disaster risk than the typical county in Massachusetts.
Is Norfolk County at risk for flooding?
Yes, Norfolk County's flooding risk is at the 95th percentile nationally. This places it in the top quartile for this hazard type.
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 Norfolk County higher risk than average?
Norfolk County's composite risk score of 92th percentile is above the Massachusetts state average of 79th percentile. This elevated risk is driven by flooding exposure (95th percentile), along with hurricane and earthquake and tornado risk. Geographic location, terrain, climate patterns, and proximity to flood zones or fault lines all influence a county's risk profile.
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.