Suffolk County
Massachusetts — Natural Disaster Risk Assessment
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
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 |
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.
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.