Mercer County, New Jersey

Mercer County, New Jersey has a relatively high overall risk from natural hazards in FEMA's National Risk Index. Its risk score is higher than 95% of US counties. It ranks 9th of 21 counties in New Jersey. The costliest hazards here are inland flooding, hurricanes and strong wind. FEMA estimates about $176 million a year in expected losses, or roughly $456 per resident. Since 1965 it has been included in 25 federal disaster or emergency declarations for natural events (16 major disasters). The most recent was in September 2021 (remnants of hurricane ida). About 1 in 83 homes here carry federal flood insurance (1,294 policies). Since 1978, federal flood insurance has paid about $48 million on 2,432 claims here, including $15 million for floods in 2011.

FEMA National Risk Index December 2025; OpenFEMA declarations to Nov 6, 2026; NFIP records. Updated November 6, 2026.

Scores are percentiles: a score of 90 means higher risk than about 90% of US counties for that hazard. Hazards FEMA does not rate here are left out. Social vulnerability is relatively moderate and community resilience is relatively high in FEMA's measures.

The National Weather Service has logged 550 storm reports in Mercer County since 1955, with 4 deaths and 23 injuries and about $194 million in reported damage. The strongest on record here was an F2 tornado on August 17, 1988.

Source: NOAA Storm Events Database, county-based reports through Jul 27, 2026. Tornado records start in 1950, hail and wind in 1955, and floods and other storm types in 1996, so older decades undercount. Damage is in dollars of the year it happened and is often an estimate. Winter storms, heat and hurricanes are logged by forecast zone, not county, so they are not counted here.

Since 1861, 4 hurricanes and 20 tropical storms have passed within 65 miles of the center of Mercer County, 13 of them since 1950. The strongest was Hurricane Gloria (1985), with top winds near 90 mph about 60 miles away.

Source: NOAA National Hurricane Center best-track records (HURDAT2), 1851 to 2025 for the Atlantic and 1949 to 2025 for the eastern Pacific. A storm counts if its track passed within 65 miles of the county's center while it was a tropical storm or hurricane. Strength is the storm's top sustained wind at that point, not the wind measured in the county. Older storms over the open sea were sometimes missed.

National Flood Insurance Program (NFIP) records only; private flood policies are not included. Home counts as of Aug 3, 2026. Since 2021 NFIP prices each home separately under Risk Rating 2.0, so your price depends on the building, not the county. Ask an agent for a quote.

Older homes and mobile homes usually suffer more damage in storms, floods and earthquakes, and can cost more to insure. If you are buying, ask about roof age, foundation bolting and any retrofits. Source: US Census Bureau, American Community Survey 2020 to 2024 5-year estimates; 151,138 housing units.

Sources: FEMA National Risk Index (December 2025), OpenFEMA Disaster Declarations Summaries, and NFIP policy and claims data. Hazard Compass is independent and not affiliated with FEMA. These figures describe the whole county, not a single property, and are not insurance or safety advice. Report a problem.