Norfolk County
Massachusetts — Natural Disaster Risk Assessment
MediumComposite Risk Score
National percentile: 92th
Norfolk County faces medium composite natural disaster risk (NRI Risk Index score 92.0, 92th national percentile), driven primarily by riverine flood and hurricane exposure. Expected annual loss across all 18 hazard types is $147M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Top Hazards
All 18 Hazard Risks
| Riverine Flood | High | 2.86 / yr | $103M |
| Hurricane | Medium | 0.18 / yr | $16M |
| Earthquake | Medium | 0.00 / yr | $9M |
| Ice Storm | High | 1.78 / yr | $1M |
| Heat Wave | Medium | 6.07 / yr | $4M |
| Lightning | High | 20.99 / yr | $1M |
| Coastal Flood | High | 7.92 / yr | $5M |
| Cold Wave | Medium | 1.30 / yr | $3M |
| Landslide | Low | 0.23 / yr | $9K |
| Tornado | Medium | 0.08 / yr | $3M |
| Strong Wind | Medium | 0.92 / yr | $1M |
| Wildfire | Very Low | 0.00 / yr | $61K |
| Winter Weather | Low | 12.98 / yr | $81K |
| Drought | Low | 5.77 / yr | $98K |
| Hail | Very Low | 1.84 / yr | $43K |
| Avalanche | Very Low | 0.00 / 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 Norfolk County?
Norfolk County has a composite FEMA National Risk Index score of 92.0 out of 100, placing it in the Medium category and the 92th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Norfolk County?
The three highest-rated hazards are Riverine Flood (High, $103M EAL), Hurricane (Medium, $16M EAL), Earthquake (Medium, $9M EAL). These account for most of the county's expected annual losses.
How does Norfolk County compare to other Massachusetts counties?
Norfolk County ranks #6 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. Norfolk County's $147M EAL is a statistical average, not a guarantee for any specific year or address.