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FEMA NRI 1.19.0Updated Nov 2023 · Coverage 2014–2023Methodology

Union County Disaster Risk

Union County, New Jersey

FEMA Risk Rating

Relatively High

National Percentile

95th

of 3,144 counties

State Rank

#8

of 21 (1 = highest risk)

Flood Risk

98th

percentile

Hazard Risk Breakdown

Flood

River, coastal, and surface flooding risk

Relatively High

Higher than 98% of US counties

Wildfire

Wildland and wildland-urban interface fire risk

Very Low

Higher than 16% of US counties

Tornado

Tornado and severe thunderstorm risk

Moderate

Higher than 87% of US counties

Earthquake

Seismic activity and ground shaking risk

Relatively High

Higher than 95% of US counties

Hurricane

Tropical cyclone and hurricane risk

Moderate

Higher than 89% of US counties

Risk Overview

About Natural Disaster Risk in Union County, New Jersey

Union County faces well-above-average natural hazards

Union County scores 95.48 on the composite risk scale, earning a relatively high risk rating that significantly exceeds national averages for disaster exposure. This elevated standing reflects Union's concentrated vulnerability to multiple major hazard types, particularly in urban and coastal contexts.

Union ranks as New Jersey's riskiest county

At 95.48, Union County leads all New Jersey counties in composite disaster risk, well above the state average of 90.81. Union's elevated rank reflects a dangerous convergence of flood, tornado, earthquake, and hurricane threats concentrated in one county.

Union significantly outranks all surrounding counties

Union (95.48) substantially exceeds risk levels in Somerset (90.94), Salem (76.53), Sussex (77.45), and Warren (80.76), making it distinctly the most hazard-exposed county in the region. No nearby county approaches Union's composite risk profile.

Flooding and tornadoes pose critical threats

Union's flood risk reaches 97.52—among the highest in the nation—while tornado risk climbs to 87.15, reflecting its vulnerable urban and coastal geography. Earthquake risk also spikes to 95.07, and hurricane exposure registers at 88.99, creating a perfect storm of overlapping hazards.

Flood insurance is non-negotiable in Union County

Given Union's exceptional 97.52 flood risk score, flood insurance is essential for all residents, even those outside designated FEMA flood zones. Homeowners should also invest in structural reinforcements against severe weather, keep emergency supplies stocked, and maintain a detailed disaster response plan for their family.

Source: FEMA National Risk Index · Narrative reviewed by Evan Brooks, Data Editor

Preparedness Guide

What to Prepare for in Union County

Top Hazards by Exposure

  1. #1
    FloodPrepare
    98th percentile
  2. #2
    EarthquakePrepare
    95th percentile
  3. #3
    HurricanePrepare
    89th percentile

Source: FEMA National Risk Index v1.19.0 · Percentiles are national (3,144 counties)

Local Resources

Risk Advisory: Union County

Risk Verdict

With a national rank of 95th percentile, Union County faces above-average natural disaster pressure across several hazard categories. High composite risk signals that multiple hazard types are elevated simultaneously; planning for more than one scenario is important in Union County.

Hazard Breakdown

Flood risk is Union County's dominant natural hazard, ranked at the 98th percentile nationally under FEMA's National Risk Index. Earthquake ranks second at the 95th percentile nationally. Additional tracked hazards include hurricane (89th percentile), tornado (87th percentile), wildfire (16th percentile).

Preparedness Context

Union County's dominant hazard is flooding, ranked at the 98th percentile nationally. In addition to flood insurance, residents should identify their nearest evacuation shelter and store key documents in waterproof containers. The county's second-ranked hazard, earthquake at the 95th percentile nationally, means Union County residents face compounding risks from multiple natural hazard types during peak seasons. Union County's county emergency management office publishes hazard-specific guidance tailored to local conditions; bookmarking that resource and the county's alert system is a practical first step for any household.

Regional Context

At 4.7 points from the New Jersey county mean, Union County's overall disaster risk profile is close to typical for this state, with no dramatic deviation in either direction.

Is your household prepared for Union County's hazards?

Review FEMA's county-specific preparedness checklists and emergency planning guides.

FEMA Ready Guide →

Frequently Asked Questions

What is the natural disaster risk in Union County, NJ?
Union County has a FEMA National Risk Index rating of Relatively High, placing it in the 95th 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.
What types of natural hazards affect Union County?
Union County is evaluated for five major natural hazard types: flooding (98th percentile), earthquake (95th percentile), hurricane (89th percentile), tornado (87th percentile), wildfire (16th percentile). The highest-risk hazard is flooding at the 98th 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.
How does Union County risk compare to the New Jersey average?
Union County's composite risk percentile is 95th, compared to the New Jersey state average of 91th percentile. The state's overall risk rating is Relatively Moderate. This means Union County faces higher natural disaster risk than the typical county in New Jersey.
Is Union County at risk for flooding?
Yes, Union County's flooding risk is at the 98th percentile nationally. This places it in the top quartile for this hazard type.
How is natural disaster risk measured?
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.
Why is Union County higher risk than average?
Union County's composite risk score of 95th percentile is above the New Jersey state average of 91th percentile. This elevated risk is driven by flooding exposure (98th percentile), along with earthquake 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.

Counties with Similar Risk

Mercer County

New Jersey

-0.1

Relatively High

95th percentile

Passaic County

New Jersey

+0.3

Relatively High

96th percentile

Ocean County

New Jersey

+0.7

Relatively High

96th percentile

By Evan Brooks, Data EditorUpdated Reviewed by Evan Brooks, Data Editor

Data Source

Risk data sourced from the FEMA National Risk Index (NRI). Risk scores are relative rankings (0–100) across all US counties — not absolute risk measures. Higher scores indicate higher relative risk compared to other counties.

Disclaimer: This data is informational only. It is not financial, insurance, or legal advice. Always consult a qualified professional before making insurance or real estate decisions.

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