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

Middlesex County Disaster Risk

Middlesex County, Massachusetts

FEMA Risk Rating

Relatively High

National Percentile

97th

of 3,144 counties

State Rank

#1

of 14 (1 = highest risk)

Flood Risk

99th

percentile

Hazard Risk Breakdown

Flood

River, coastal, and surface flooding risk

Relatively High

Higher than 99% of US counties

Wildfire

Wildland and wildland-urban interface fire risk

Relatively Low

Higher than 73% of US counties

Tornado

Tornado and severe thunderstorm risk

Moderate

Higher than 90% of US counties

Earthquake

Seismic activity and ground shaking risk

Relatively High

Higher than 96% of US counties

Hurricane

Tropical cyclone and hurricane risk

Relatively High

Higher than 95% of US counties

Risk Overview

About Natural Disaster Risk in Middlesex County, Massachusetts

Middlesex faces above-average disaster risk

Middlesex County scores 96.95 on composite risk, placing it in the relatively high category—well above the national average. This score reflects substantial exposure across multiple hazard types, from earthquakes to hurricanes.

Highest-risk county in Massachusetts

Middlesex ranks as the riskiest county in Massachusetts, with a composite score of 96.95 compared to the state average of 78.84. The county's 23% elevation above the state baseline signals concentrated vulnerability across most natural disaster categories.

Significantly riskier than surrounding counties

Middlesex outpaces its regional neighbors: Suffolk County scores 93.51, Worcester scores 93.54, and Norfolk scores 92.02. The county's flood risk (98.51) is the highest in its region, driven by extensive coastal and riverine exposure.

Floods and earthquakes top your hazard list

Flood risk dominates at 98.51—among the highest in the nation—while earthquake risk reaches 96.09. Tornado risk (90.11) and hurricane risk (95.45) round out Middlesex's multi-faceted threat profile, requiring comprehensive preparedness.

Prioritize flood and earthquake coverage now

Standard homeowners insurance does not cover flood or earthquake damage; both require separate policies in Middlesex. Given your county's exceptional exposure, bundling flood and earthquake coverage with your home policy is essential protection against your area's primary risks.

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

Preparedness Guide

What to Prepare for in Middlesex County

Top Hazards by Exposure

  1. #1
    FloodPrepare
    99th percentile
  2. #2
    EarthquakePrepare
    96th percentile
  3. #3
    HurricanePrepare
    95th percentile

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

Risk Advisory: Middlesex County

Risk Verdict

Natural hazard exposure in Middlesex County is notably high, placing it at the 97th percentile among all U.S. counties. Middlesex County's elevated composite score reflects cumulative multi-hazard exposure; households should prepare for the county's two or three primary hazard types.

Hazard Breakdown

Flood risk is Middlesex County's dominant natural hazard, ranked at the 99th percentile nationally under FEMA's National Risk Index. Earthquake ranks second at the 96th percentile nationally. Additional tracked hazards include hurricane (95th percentile), tornado (90th percentile), wildfire (73th percentile).

Preparedness Context

With flood ranked as the primary hazard at the 99th percentile nationally, Middlesex County households should build a go-bag that includes important documents, medications, and supplies to sustain the family for at least three days if evacuation is needed. Alongside flooding, earthquake exposure at the 96th percentile means households benefit from a multi-hazard preparedness plan rather than focusing on flood alone. A waterproof container for documents (insurance policies, ID, prescriptions) and a clear household communication plan for when phone networks are congested are the two highest-value low-cost preparedness steps for Middlesex County households.

Regional Context

A composite score 18.1 points above the Massachusetts state average puts Middlesex County in a higher-risk category than most counties in the state.

Is your household prepared for Middlesex 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 Middlesex County, MA?
Middlesex County has a FEMA National Risk Index rating of Relatively High, placing it in the 97th 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 Middlesex County?
Middlesex County is evaluated for five major natural hazard types: flooding (99th percentile), earthquake (96th percentile), hurricane (95th percentile), tornado (90th percentile), wildfire (73th percentile). The highest-risk hazard is flooding at the 99th 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 Middlesex County risk compare to the Massachusetts average?
Middlesex County's composite risk percentile is 97th, compared to the Massachusetts state average of 79th percentile. The state's overall risk rating is Relatively Low. This means Middlesex County faces higher natural disaster risk than the typical county in Massachusetts.
Is Middlesex County at risk for flooding?
Yes, Middlesex County's flooding risk is at the 99th 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 Middlesex County higher risk than average?
Middlesex County's composite risk score of 97th percentile is above the Massachusetts state average of 79th percentile. This elevated risk is driven by flooding exposure (99th percentile), along with earthquake and hurricane and tornado and wildfire 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.