New Castle County, Delaware
Natural disaster risk, federal disaster history and flood insurance facts.
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
- 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.
- Insulate pipes in outside walls, crawl spaces and garages.
- Know how to shut off the main water valve.
- Ask whether an older house is bolted to its foundation.
- Consider separate earthquake insurance where risk is high.
All 18 hazards
What the ratings mean ›| Hazard | Rating | Score | Expected loss a year | |
|---|---|---|---|---|
| Inland flooding | 97.6 | $150M | ||
| Cold wave | 93.4 | $10M | ||
| Earthquake | 92.9 | $9M | ||
| Heat wave | 95.3 | $7M | ||
| Tornado | 88.1 | $7M | ||
| Hurricane | 88.4 | $6M | ||
| Coastal flooding | 83.8 | $4M | ||
| Winter weather | 99.5 | $2M | ||
| Strong wind | 88.3 | $2M | ||
| Drought | 84.0 | $1M | ||
| Ice storm | 89.0 | $913K | ||
| Lightning | 81.3 | $847K | ||
| Hail | 24.2 | $97K | ||
| Wildfire | 60.6 | $95K | ||
| Landslide | 76.6 | $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
Most recent
Show all 15
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.
Strongest tornadoes
| Date | Strength | Near | Hurt / killed |
|---|---|---|---|
| Apr 28, 1961 | F3 | – | 0 / 0 |
| Jun 9, 1989 | F2 | – | 1 / 0 |
| Sep 28, 2004 | F2 | Wilmington Arpt | 0 / 0 |
| Sep 5, 1979 | F2 | – | 5 / 0 |
| Oct 18, 1990 | F2 | – | 0 / 0 |
Most damaging storms
| Date | Type | Near | Damage |
|---|---|---|---|
| Sep 15, 2003 | Flash Flood | North Portion | $16M |
| Sep 16, 1999 | Flash Flood | Countywide | $8M |
| Sep 1, 2021 | Flash Flood | Coochs Bridge | $4M |
| Jun 7, 1988 | Tornado | – | $3M |
| Jun 9, 1989 | Tornado | – | $3M |
| Sep 28, 2004 | Tornado | Wilmington 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.
Strongest storms nearby
| Date | Storm | Strength | Closest |
|---|---|---|---|
| Oct 23, 1878 | Unnamed | Category 1, 90 mph | 54 mi |
| Sep 16, 1903 | Unnamed | Category 1, 80 mph | 60 mi |
| Jul 13, 1996 | Bertha | Tropical storm, 70 mph | 45 mi |
| Sep 27, 1861 | Unnamed | Tropical storm, 70 mph | 49 mi |
| Aug 4, 2020 | Isaias | Tropical storm, 65 mph | 64 mi |
| Aug 28, 1971 | Doria | Tropical storm, 65 mph | 49 mi |
Most recent storms
| Date | Storm | Strength | Closest |
|---|---|---|---|
| Jul 9, 2021 | Elsa | Tropical storm, 60 mph | 63 mi |
| Aug 4, 2020 | Isaias | Tropical storm, 65 mph | 64 mi |
| Sep 6, 2008 | Hanna | Tropical storm, 50 mph | 47 mi |
| Jul 13, 1996 | Bertha | Tropical storm, 70 mph | 45 mi |
| Sep 26, 1992 | Danielle | Tropical storm, 45 mph | 58 mi |
| Aug 28, 1971 | Doria | Tropical storm, 65 mph | 49 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 ›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
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 counties | Overall risk | Top hazard |
|---|---|---|
| New Castle County | Inland flooding | |
| Sussex County | Inland flooding | |
| Kent County | Inland flooding |
Neighboring counties
| County | Overall risk | Declarations |
|---|---|---|
| Delaware County, PA | 22 | |
| Chester County, PA | 24 | |
| Gloucester County, NJ | 25 | |
| Kent County | 15 | |
| Cecil County, MD | 19 | |
| Salem County, NJ | 23 | |
| Kent County, MD | 19 |
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.