Suffolk County Disaster Risk

Suffolk County has a FEMA National Risk Index rating of Relatively Moderate, placing it in the 94th 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.

Suffolk County is evaluated for five major natural hazard types: earthquake (95th percentile), flooding (95th percentile), hurricane (94th percentile), tornado (75th percentile), wildfire (9th percentile). The highest-risk hazard is earthquake 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.

Suffolk County's composite risk percentile is 94th, compared to the Massachusetts state average of 79th percentile. The state's overall risk rating is Relatively Low. This means Suffolk County faces higher natural disaster risk than the typical county in Massachusetts.

Yes, Suffolk County's earthquake risk is at the 95th percentile nationally. This places it in the top quartile for this hazard type. For flooding specifically, Suffolk County is at the 95th percentile.

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.

Suffolk County's composite risk score of 94th percentile is above the Massachusetts state average of 79th percentile. This elevated risk is driven by earthquake exposure (95th percentile), along with flooding and hurricane and tornado risk. Geographic location, terrain, climate patterns, and proximity to flood zones or fault lines all influence a county's risk profile.