Somerset County, New Jersey Natural Disaster Risk
FEMA National Risk Index assessment · NJ
MediumComposite Risk Score
National percentile: 91th
Somerset County faces medium composite natural disaster risk (NRI Risk Index score 90.9, 91th national percentile), driven primarily by riverine flood and winter weather exposure. Expected annual loss across all 18 hazard types is $161M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Somerset County carries a medium composite natural disaster risk, with a National Risk Index score of 90.9 out of 100 — placing it in the 91st 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 riverine flood (rivers and streams overflowing their banks after heavy rain or snowmelt) at High risk — $126M in expected annual loss and about 6.29 events per year; winter weather (heavy snow, blizzards, and hazardous winter conditions) at High risk — $1M in expected annual loss and about 12.00 events per year; and strong wind (damaging straight-line winds outside of tornadoes and hurricanes) at High risk — $4M in expected annual loss and about 6.80 events per year. Across all hazards, FEMA estimates $161M in expected annual loss for a population of 345K.
Beyond physical exposure, Somerset County has a very low 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). A less vulnerable population paired with strong resilience helps the community absorb and recover from events.
History supports the rating: Somerset County has received 30 federal disaster declarations since 1965, including 9 for hurricane events and 6 for severe storm events. The most recent was Remnants of Hurricane Ida (hurricane), declared in September 2021.
Among 21 New Jersey counties, Somerset County ranks #15 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Riverine Flood | High | 6.29 / yr | $126M |
| Winter Weather | High | 12.00 / yr | $1M |
| Strong Wind | High | 6.80 / yr | $4M |
| Ice Storm | High | 0.95 / yr | $2M |
| Earthquake | Low | 0.00 / yr | $7M |
| Heat Wave | Medium | 7.42 / yr | $4M |
| Hurricane | Medium | 0.11 / yr | $5M |
| Lightning | High | 34.15 / yr | $1M |
| Cold Wave | Medium | 0.89 / yr | $4M |
| Tornado | Medium | 0.12 / yr | $5M |
| Drought | Low | 2.88 / yr | $432K |
| Wildfire | Very Low | 0.00 / yr | $33K |
| Coastal Flood | Very Low | 0.01 / yr | $7K |
| Landslide | Very Low | 0.14 / yr | $273 |
| Hail | Very Low | 2.43 / yr | $87K |
| Avalanche | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
| Volcanic Activity | Very Low | 0.00 / yr | $0 |
Disaster History
Somerset County has received 30 federal disaster declarations since 1965, most recently Remnants of Hurricane Ida in September 2021. Most frequent causes: Hurricane (9), Severe Storm (6), Flood (5).
| Declared | Type | Disaster |
|---|---|---|
| September 2021 | Hurricane | Remnants of Hurricane Ida |
| September 2021 | Hurricane | Remnants of Hurricane Ida |
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| June 2018 | Severe Storm | Severe Winter Storm and Snowstorm |
| March 2016 | Severe Storm | Severe Winter Storm and Snowstorm |
| October 2012 | Hurricane | Hurricane Sandy |
| October 2012 | Hurricane | Hurricane Sandy |
| November 2011 | Severe Storm | Severe Storm |
| August 2011 | Hurricane | Hurricane Irene |
Showing the 10 most recent of 30 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Somerset County?
Somerset County has a composite FEMA National Risk Index score of 90.9 out of 100, placing it in the Medium category and the 91th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Somerset County?
The three highest-rated hazards are Riverine Flood (High, $126M EAL), Winter Weather (High, $1M EAL), Strong Wind (High, $4M EAL). These account for most of the county's expected annual losses.
How does Somerset County compare to other New Jersey counties?
Somerset County ranks #15 of 21 New Jersey counties for overall natural disaster risk, with a medium rating.
How many federally declared disasters has Somerset County had?
FEMA records 30 federal disaster declarations for Somerset County since 1965, most often 9 for hurricane events and 6 for severe storm events. The most recent was Remnants of Hurricane Ida, declared in September 2021.
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. Somerset County's $161M EAL is a statistical average, not a guarantee for any specific year or address.