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New Castle County, Delaware

Natural disaster risk, federal disaster history and flood insurance facts.

Relatively High overall risk
1st of 3highest risk in Delaware
$202Mexpected losses a year
15federal declarations
1 in 111homes with flood insurance
Photo: Quintin Soloviev, CC BY 4.0

New Castle County, Delaware 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 1st of 3 counties in Delaware. The costliest hazards here are inland flooding, cold waves and earthquakes. FEMA estimates about $202 million a year in expected losses, or roughly $355 per resident. Since 1965 it has been included in 15 federal disaster or emergency declarations for natural events (10 major disasters). The most recent was in October 2021 (remnants of hurricane ida). Fewer than 1 in 100 homes here carry federal flood insurance (1,599 policies). Since 1978, federal flood insurance has paid about $51 million on 1,575 claims here, including $18 million for floods in 2003.

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

Top risks in New Castle County

$150 million a yearExpected losses. Damaging events about 7 times a year.
  • Check the FEMA flood map for your address, and ask the seller or landlord about past flooding.
  • Price a flood policy now. Most new federal policies take 30 days to start.
$10.5 million a yearExpected losses. Damaging events about once a year.
  • Insulate pipes in outside walls, crawl spaces and garages.
  • Know how to shut off the main water valve.

Earthquake

Moderate
$9.2 million a yearExpected losses. Damaging events about once every 620 years.
  • Ask whether an older house is bolted to its foundation.
  • Consider separate earthquake insurance where risk is high.
HazardRatingScoreExpected loss a year
Inland floodingHigh97.6
$150M
Cold waveHigh93.4
$10M
EarthquakeModerate92.9
$9M
Heat waveModerate95.3
$7M
TornadoModerate88.1
$7M
HurricaneModerate88.4
$6M
Coastal floodingHigh83.8
$4M
Winter weatherVery High99.5
$2M
Strong windHigh88.3
$2M
DroughtModerate84.0
$1M
Ice stormHigh89.0
$913K
LightningModerate81.3
$847K
HailVery Low24.2
$97K
WildfireVery Low60.6
$95K
LandslideLow76.6
$12K

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 low and community resilience is very high in FEMA's measures.

Federal disaster history

Recent disasters nationwide ›

Declarations by decade

Federal declarations for natural events that included New Castle County. 2020s bar runs to November 2026.

By type

Hurricane9
Snowstorm4
Drought1
Severe Storm1

Most recent

Oct 24, 2021Remnants of Hurricane IdaMajor disaster
Oct 2, 2020Tropical Storm IsaiasMajor disaster
Nov 16, 2012Hurricane SandyMajor disaster
Oct 29, 2012Hurricane SandyEmergency
Aug 28, 2011Hurricane IreneEmergency
Mar 31, 2010Severe Winter Storms and SnowstormsMajor disaster
Sep 30, 2005Hurricane Katrina EvacuationEmergency
Nov 15, 2004Severe Storms, Tornadoes, and Flooding From the Remnants OfMajor disaster
Sep 23, 2003Tropical Storm HenriMajor disaster
Sep 20, 2003Hurricane IsabelMajor disaster
Show all 15
Mar 20, 2003SnowEmergency
Sep 21, 1999Hurricane Floyd Major Disaster DeclarationsMajor disaster
Jan 12, 1996Blizzard of 96 (Severe Snow Storm)Major disaster
Mar 18, 1993Severe Snowfall & Winter StormEmergency
Aug 18, 1965Water ShortageMajor disaster

Delaware also had 1 statewide declarations that did not name single counties.

Storm history since 1954

Tornado risk by county ›

The National Weather Service has logged 886 storm reports in New Castle County since 1954, with 6 deaths and 32 injuries and about $40.3 million in reported damage. The strongest on record here was an F3 tornado on April 28, 1961.

28tornadoes
73hail reports, largest 2.5 inches
454damaging thunderstorm winds
241floods and flash floods

Strongest tornadoes

DateStrengthNearHurt / killed
Apr 28, 1961F3–0 / 0
Jun 9, 1989F2–1 / 0
Sep 28, 2004F2Wilmington Arpt0 / 0
Sep 5, 1979F2–5 / 0
Oct 18, 1990F2–0 / 0

Most damaging storms

DateTypeNearDamage
Sep 15, 2003Flash FloodNorth Portion$16M
Sep 16, 1999Flash FloodCountywide$8M
Sep 1, 2021Flash FloodCoochs Bridge$4M
Jun 7, 1988Tornado–$3M
Jun 9, 1989Tornado–$3M
Sep 28, 2004TornadoWilmington Arpt$1M

Source: NOAA Storm Events Database, county-based reports through Jul 28, 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.

Hurricanes and tropical storms

Hurricane risk by county ›

Since 1861, 2 hurricanes and 20 tropical storms have passed within 65 miles of the center of New Castle County, 11 of them since 1950. The strongest was an unnamed hurricane in 1878, with top winds near 90 mph about 54 miles away.

2hurricanes
0major hurricanes (Category 3+)
20tropical storms
2021most recent: Elsa

Strongest storms nearby

DateStormStrengthClosest
Oct 23, 1878UnnamedCategory 1, 90 mph54 mi
Sep 16, 1903UnnamedCategory 1, 80 mph60 mi
Jul 13, 1996BerthaTropical storm, 70 mph45 mi
Sep 27, 1861UnnamedTropical storm, 70 mph49 mi
Aug 4, 2020IsaiasTropical storm, 65 mph64 mi
Aug 28, 1971DoriaTropical storm, 65 mph49 mi

Most recent storms

DateStormStrengthClosest
Jul 9, 2021ElsaTropical storm, 60 mph63 mi
Aug 4, 2020IsaiasTropical storm, 65 mph64 mi
Sep 6, 2008HannaTropical storm, 50 mph47 mi
Jul 13, 1996BerthaTropical storm, 70 mph45 mi
Sep 26, 1992DanielleTropical storm, 45 mph58 mi
Aug 28, 1971DoriaTropical storm, 65 mph49 mi

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.

Flood insurance in New Castle County

Check your address flood zone ›
0.9%of homes have federal flood insurance (1,599 policies)
44.5%of homes in mapped high-risk flood zones are insured
$51.4 millionpaid on 1,575 flood claims since 1978
2003costliest year, with $18.1 million paid

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.

Homes in New Castle County

$352,200median home value (Delaware $352,000, US $332,700)
1975median year homes were built (Delaware 1987, US 1980)
56%of homes built before 1980, before many modern wind, quake and flood building rules
2%of homes are mobile homes, which are the least safe in tornadoes and high winds

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; 236,079 housing units.

Compare in Delaware

All 3 ›
Largest countiesOverall riskTop hazard
New Castle CountyHighInland flooding
Sussex CountyModerateInland flooding
Kent CountyModerateInland flooding

Neighboring counties

CountyOverall riskDeclarations
Delaware County, PAModerate22
Chester County, PAModerate24
Gloucester County, NJModerate25
Kent CountyModerate15
Cecil County, MDLow19
Salem County, NJLow23
Kent County, MDVery Low19

Cities in New Castle County

Common questions about New Castle County

What is the biggest natural hazard in New Castle County?

Inland flooding has the highest expected yearly losses in New Castle County, about $150 million a year in FEMA's estimate. Cold wave is second at $10.5 million.

How many federal disasters has New Castle County had?

New Castle County has been included in 15 federal disaster or emergency declarations for natural events since 1965, including 10 major disasters. The most recent was Remnants of Hurricane Ida in October 2021.

Is New Castle County a high-risk place to live?

Its overall rating is Relatively High, 1st highest of 3 in Delaware. A county rating covers the whole area. Risk at one address can be much higher or lower, so check the FEMA flood map and ask about the home's history.

Do I need flood insurance in New Castle County?

Standard home insurance does not cover flooding. About 1 in 111 homes in New Castle County has federal flood insurance. Lenders require it in mapped high-risk zones, but many flood claims come from outside those zones.

How many tornadoes has New Castle County had?

NOAA records list 28 tornadoes in New Castle County since 1950. The strongest was an F3 tornado on April 28, 1961. The weather service has also logged 73 hail reports and 241 floods here.

How many hurricanes have hit New Castle County?

NOAA's hurricane records show 2 hurricanes and 20 tropical storms passing within 65 miles of the center of New Castle County. The strongest was an unnamed hurricane in 1878, with winds near 90 mph.

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.