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Delaware Environment & Hazard Risk

1 county rated high or very high risk. 4,605 storm events since 1996, #50 among states.

Expected yearly loss
$377M
$381 per person
Storm events since 1996
4,605
Most often thunderstorm wind
Flood insurance policies
17,547
$90.98M in claims paid
Superfund sites
26
51 toxic release facilities

Risk by county

FEMA National Risk Index rating, highest risk first

CountyOverall riskTop hazardFlood policiesFlood claims paid
New Castle CountyHighWinter weather1,599$51.68M
Sussex CountyModerateCold wave15,126$35.73M
Kent CountyModerateCold wave822$3.57M

Costliest hazards

Expected annual loss in Delaware, all counties combined

  • Hurricane$51.81M/yr · 1 county high
  • Cold wave$37.63M/yr · 3 counties high
  • Coastal flooding$19.03M/yr · 2 counties high
  • Earthquake$12.6M/yr
  • Heat wave$12M/yr
  • Tornado$11.08M/yr
  • Strong wind$4.11M/yr · 2 counties high
  • Winter weather$3.75M/yr · 3 counties high
  • Drought$3.64M/yr
  • Lightning$2.1M/yr · 1 county high

Storm events by type

Since 1996: 38 deaths, $179M in property and crop damage

  • Thunderstorm Wind939 · 1 death
  • Strong Wind505 · 4 deaths
  • Winter Weather425 · 3 deaths
  • Heavy Rain359
  • Flash Flood270 · 4 deaths
  • Heat216 · 8 deaths
  • High Wind216
  • Drought207
  • Coastal Flood193
  • Flood167
  • Lightning146
  • Dense Fog145

Events per year

Storm events per year in Delaware

Most damaging storms

Since 2017, ranked by deaths, injuries and damage

  • Thunderstorm Wind50 kt wind07/01/2025

    Silverbrook, New Castle County

    1 death, 1 injured

    What happened

    A tree was blown down onto a vehicle traveling in the right westbound lane of Lancaster Pike approaching Hedgerow Place in Wilmington. There were two occupants in the vehicle.

  • Rip Current09/04/2023

    Delaware Beaches

    1 death

    What happened

    Broadcast media reports a man went missing while swimming in Rehoboth Beach. Rip currents were the most likely cause of death. The body was found 1 day later.

  • TornadoEF3, 14.3 mi path, 700 yd wide04/01/2023

    Dublin Hill, Sussex County

    1 death

    What happened

    The Bridgeville-Ellendale Tornado began around 5:59 PM EDT near the intersection of Polk Road and Dublin Hill Road where a section of a small barn roof was blown off. The tornado continued east-northeast crossing Seashore Highway. Along this section of the |damage path, a couple wooden power poles were blown down along with several trees uprooted or snapped. On tree fell onto a house causing significant collateral roof damage. The tornado continued eastward paralleling Newton Road where a farmstead sustain significant tree damage. About a half dozen parked semi-trailers were blow over along a driveway. Farther east, more tree damage and snapped power poles were observed. Near the intersection of Precious Lane and Newton Road, a 2 story house was collapsed after appearing to have slid off its foundation. A small outbuilding was also severely damaged nearby. Debris from this area was blown several hundred yards east into nearby fields. Another farmstead was struck by the tornado as it continued east on Dale Farm Road. A large barn had 2 exterior walls blown out and a smaller shed was blown over. Several trees were also snapped or uprooted on the |property.||The tornado continued...

  • Winter Storm01/07/2017

    Kent

    5 injured

    What happened

    Snow began during the early morning hours on the 7th, then continued, heavy at times through the late afternoon hours, ending by sunset. Generally 3 to 6 inches of snow fell in Kent County during the storm, with the highest totals in the south. Some representative snowfall reports include 6.5 inches in Dover, 4.8 inches in Woodside, 3.3 inches in Felton, and 3.0 inches in Hazlettville.||DELDOT reported five personal injury accidents during the storm.

  • Flash Flood09/01/2021

    Coochs Bridge, New Castle County

    $3.6M damage

    What happened

    Widespread flash flooding occurred in New Castle County with many road closures. Several rivers and creeks in the county overflowed their banks, including the Christina River, the Red Clay Creek and the White Clay Creek. More than 200 residences were affected by the flooding.

  • Thunderstorm Wind50 kt wind07/17/2024

    Monroe Park, New Castle County

    2 injured

    What happened

    Live local news coverage report of 2 people rushed to hospital after tree fell onto a home in Wilmington. Time estimated. Exact location not known.

Hurricanes and tropical storms

Storms whose track crossed the state, newest first

Flood insurance

National Flood Insurance Program policies and claims

17,547 homes in Delaware have flood insurance, about 4.8% of residential buildings. In high-risk flood zones, 12,108 of 20,853 homes (58%) are insured.

Flood claims paid per year in Delaware
  • Hurricane Sandy$17.43M · 1,495 claims
  • Flooding$9.8M · 1,282 claims
  • Hurricane Ida$7.81M · 91 claims
  • Hurricane Floyd$7.13M · 218 claims
  • Hurricane Irene$4.04M · 205 claims
  • Hurricane Isabel$1.28M · 62 claims

Drinking water

204 community water systems serve about 1,025,658 people

Since 2021, 13 systems reported 24 health-based violations. 6 systems had a violation of any kind still open at last report. These had the most:

Select a county above to see every system that serves it.

Climate in the largest cities

1991-2020 normals from the nearest NOAA weather station

CityJuly highJan lowRainSnow
Wilmington84°F24°F50.3 in12.0 in
Dover87°F28°F47.6 in13.2 in
Newark89°F25°F47.0 in-
Hockessin84°F23°F47.1 in-
Milford87°F25°F46.3 in12.8 in
Claymont89°F27°F41.6 in-
Wilmington Manor87°F26°F45.3 in20.2 in
Georgetown88°F29°F43.9 in-

Pollution sites

26 Superfund sites and 51 toxic release facilities

Superfund sites

All 26 in Delaware

Largest toxic releases

All 51 in Delaware

Facilities in Delaware reported 5.6 million lbs of toxic releases in 2024, 512,464 lbs of it into the air.

Frequently asked questions

What is the biggest natural hazard in Delaware?
By expected annual loss, hurricane costs the most in Delaware ($51.81M a year), according to FEMA's National Risk Index.
How many storms hit Delaware each year?
NOAA recorded 4,605 storm events in Delaware since 1996, about 149 a year. The most common type is thunderstorm wind.
How many homes in Delaware have flood insurance?
17,547 residential flood insurance policies are in force in Delaware. Since 1978 the National Flood Insurance Program has paid $90.98M on 6,258 claims here.
How many Superfund sites are in Delaware?
Delaware has 26 Superfund sites on or deleted from EPA's National Priorities List.

Source: FEMA, NOAA, EPA · Last updated 08/01/2026 · Storm counts include events in forecast zones that touch each county. This product uses the FEMA OpenFEMA API, but is not endorsed by FEMA.