Suffolk County, Massachusetts Natural Disaster Risk
FEMA National Risk Index assessment · MA
MediumComposite Risk Score
National percentile: 94th
Suffolk County faces medium composite natural disaster risk (NRI Risk Index score 93.5, 94th national percentile), driven primarily by lightning and heat wave exposure. Expected annual loss across all 18 hazard types is $115M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Overall natural disaster risk in Suffolk County is medium, with a National Risk Index score of 93.5 out of 100 — placing it in the 94th national percentile and near the national midpoint for natural-disaster risk. The score blends Expected Annual Loss, Social Vulnerability, and Community Resilience across all 18 FEMA hazard types.
Risk here concentrates in lightning (electrical discharges from storms that ignite fires and cause casualties) at Very High risk — $2M in expected annual loss and about 19.97 events per year; heat wave (prolonged periods of extreme heat that threaten health and infrastructure) at High risk — $9M in expected annual loss and about 5.25 events per year; and earthquake (ground shaking from sudden movement along geologic faults) at Medium risk — $12M in expected annual loss and about 0.00 events per year. Across all hazards, FEMA estimates $115M in expected annual loss for a population of 796K.
Beyond physical exposure, Suffolk County has a high social vulnerability rating (how susceptible the population is to harm) and a very high community resilience rating (its capacity to prepare for and recover from disasters). Higher vulnerability is partly offset by strong community resilience and recovery capacity.
History supports the rating: Suffolk County has received 38 federal disaster declarations since 1972, including 9 for snowstorm events and 8 for hurricane events. The most recent was Hurricane Lee (hurricane), declared in September 2023.
Among 14 Massachusetts counties, Suffolk County ranks #3 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Lightning | Very High | 19.97 / yr | $2M |
| Heat Wave | High | 5.25 / yr | $9M |
| Earthquake | Medium | 0.00 / yr | $12M |
| Riverine Flood | High | 1.68 / yr | $60M |
| Cold Wave | High | 1.19 / yr | $9M |
| Hurricane | High | 0.18 / yr | $13M |
| Coastal Flood | High | 7.40 / yr | $6M |
| Ice Storm | Medium | 1.01 / yr | $329K |
| Hail | Medium | 1.64 / yr | $615K |
| Tornado | Medium | 0.02 / yr | $3M |
| Strong Wind | Medium | 0.70 / yr | $480K |
| Winter Weather | Low | 12.22 / yr | $43K |
| Landslide | Very Low | 0.02 / yr | $406 |
| Wildfire | Very Low | 0.00 / yr | $2K |
| Avalanche | Very Low | 0.00 / yr | $0 |
| Drought | Very Low | 6.68 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
| Volcanic Activity | Very Low | 0.00 / yr | $0 |
Disaster History
Suffolk County has received 38 federal disaster declarations since 1972, most recently Hurricane Lee in September 2023. Most frequent causes: Snowstorm (9), Hurricane (8), Severe Storm (7).
| Declared | Type | Disaster |
|---|---|---|
| September 2023 | Hurricane | Hurricane Lee |
| April 2022 | Snowstorm | Severe Winter Storm and Snowstorm |
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| July 2018 | Snowstorm | Severe Winter Storm and Snowstorm |
| April 2015 | Severe Storm | Severe Winter Storm, Snowstorm, and Flooding |
| April 2013 | Severe Storm | Severe Winter Storm, Snowstorm, and Flooding |
| April 2013 | Terrorist | Explosions |
| December 2012 | Hurricane | Hurricane Sandy |
| October 2012 | Hurricane | Hurricane Sandy |
Showing the 10 most recent of 38 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Suffolk County?
Suffolk County has a composite FEMA National Risk Index score of 93.5 out of 100, placing it in the Medium category and the 94th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Suffolk County?
The three highest-rated hazards are Lightning (Very High, $2M EAL), Heat Wave (High, $9M EAL), Earthquake (Medium, $12M EAL). These account for most of the county's expected annual losses.
How does Suffolk County compare to other Massachusetts counties?
Suffolk County ranks #3 of 14 Massachusetts counties for overall natural disaster risk, with a medium rating.
How many federally declared disasters has Suffolk County had?
FEMA records 38 federal disaster declarations for Suffolk County since 1972, most often 9 for snowstorm events and 8 for hurricane events. The most recent was Hurricane Lee, declared in September 2023.
What does Expected Annual Loss (EAL) mean?
EAL is FEMA's estimate of average annual dollar losses from natural hazards, calculated from historical event data and exposure models. Suffolk County's $115M EAL is a statistical average, not a guarantee for any specific year or address.