New Castle County, DE
FEMA National Risk Index scores, disaster declarations & hazard data
New Castle County has experienced 17 federally declared disasters since 1965, most recently Remnants Of Hurricane Ida in 2022. Its overall natural hazard risk is rated Relatively High — higher risk than most US counties.
New Castle County's highest-rated hazards are winter weather, inland flooding, and heat wave, with its top risk rated "Very High" by FEMA's National Risk Index. Recorded storm events have decreased 28% over the past five years compared to the prior five-year period.
Past disasters & FEMA designations
A federal disaster declaration officially designates a county for FEMA disaster assistance. New Castle County has been designated in 17 declarations since 1965, covering 5 disaster types including hurricane (9), snowstorm (4), biological (2).
| Year | Type | Event name |
|---|---|---|
| 2022 | Hurricane | Remnants Of Hurricane Ida |
| 2021 | Hurricane | Tropical Storm Isaias |
| 2020 | Biological | Covid-19 Pandemic |
| 2020 | Biological | Covid-19 |
| 2013 | Hurricane | Hurricane Sandy |
| 2013 | Hurricane | Hurricane Sandy |
| 2011 | Hurricane | Hurricane Irene |
| 2010 | Snowstorm | Severe Winter Storms And Snowstorms |
| 2005 | Severe Storm | Severe Storms, Tornadoes, And Flooding From The Remnants Of |
| 2005 | Hurricane | Hurricane Katrina Evacuation |
Showing the 10 most recent of 17 total declarations since 1965.
Source: FEMA OpenFEMA Disaster Declarations Summaries. A single disaster can produce more than one record per county. Data current through September 2026.
Risk by hazard type
| Hazard | Risk rating | Risk score | Recorded events | Deaths | Prop. damage |
|---|---|---|---|---|---|
| Wildfire | Very Low | 60.6 | 0 | 0 | — |
| Inland Flooding | Relatively High | 97.6 | 88 | 0 | $3.7M |
| Coastal Flooding | Relatively High | 83.8 | 9 | 0 | — |
| Earthquake | Relatively Moderate | 92.9 | — | — | — |
| Heat Wave | Relatively Moderate | 95.3 | 17 | 0 | — |
| Tornado | Relatively Moderate | 88.1 | 4 | 0 | — |
| Hurricane | Relatively Moderate | 88.4 | 0 | 0 | — |
| Hail | Very Low | 24.2 | 19 | 0 | — |
| Strong Wind | Relatively High | 88.3 | 0 | 0 | — |
| Winter Weather | Very High | 99.5 | 0 | 0 | — |
| Ice Storm | Relatively High | 89 | — | — | — |
| Cold Wave | Relatively High | 93.4 | — | — | — |
| Lightning | Relatively Moderate | 81.3 | 11 | 0 | $37K |
| Drought | Relatively Moderate | 84 | 0 | 0 | — |
| Landslide | Relatively Low | 76.6 | 0 | 0 | — |
| Avalanche | Not Applicable | — | — | — | — |
| Tsunami | Insufficient Data | — | — | — | — |
| Volcanic Activity | Not Applicable | — | — | — | — |
Scores are 0–100 percentiles relative to all US counties — higher means more exposed, not that a disaster is likely this year. Event counts: NOAA Storm Events 2016–2026; earthquake counts from USGS ComCat (M3.0+, 1996–2026). See the methodology page for details.
Community vulnerability
New Castle County ranks in the 51st percentile (Moderate) for community vulnerability — a measure of how hard disaster impacts tend to hit residents. Higher vulnerability means more displacement, worse health outcomes, and slower recovery after a disaster.
| SVI theme | Percentile | Vulnerability level |
|---|---|---|
| Overall | 51st | Moderate |
| Socioeconomic status | 34th | Low |
| Household characteristics | 40th | Low |
| Racial & ethnic minority status | 84th | High |
| Housing type & transportation | 66th | Moderate |
Source: CDC/ATSDR Social Vulnerability Index 2022. Percentiles compare counties nationally — higher means more vulnerable relative to other counties. See CDC SVI for full methodology.
Future risk outlook
| Wildfire metric | National percentile | Level |
|---|---|---|
| Burn probability | 32nd | Relatively Low |
| Risk to homes | 33rd | Relatively Low |
| Buildings in direct exposure zone | 30.3% | — |
NOAA tracked 148 weather events in this county over 2016–2025: 86 in 2016–20 vs 62 in 2021–25 (-28% — frequency decreasing).
Wildfire: USDA Forest Service Wildfire Risk to Communities (RDS-2020-0016-2) — modeled values, not annual forecasts. See wildfirerisk.org. Inland flood and heat projections pending data availability; coastal sea-level projections are available for select coastal counties below — see the data page.
Nearby counties
Frequently asked questions
What natural hazards pose the greatest risk in New Castle County?
According to the FEMA National Risk Index, the highest-risk hazards in New Castle County, Delaware are winter weather, inland flooding, and heat wave. The county's overall natural hazard risk is rated Relatively High — higher risk than most US counties.
Has New Castle County received federal disaster declarations?
Yes. New Castle County has received 17 federal disaster declarations since 1965, including declarations in 2022. The most common disaster type on record is hurricane (9 declarations).
Has New Castle County had any FEMA disaster declarations in 2024, 2025, or 2026?
No federal disaster declarations have been recorded for New Castle County since the start of 2024. Its most recent declaration on record is Remnants Of Hurricane Ida in 2022.
How does New Castle County's natural hazard risk compare to nearby counties?
Among neighboring counties, Delaware County, PA has the highest overall natural hazard risk (Relatively Moderate) and Cecil County, MD has the lowest (Relatively Low). New Castle County is rated Relatively High overall.
How is New Castle County's composite disaster risk index calculated?
New Castle County's composite disaster risk index — officially FEMA's National Risk Index (NRI) — scores every US county on a 0–100 percentile scale across 18 natural hazard types, factoring in expected annual loss, social vulnerability, and community resilience. New Castle County's composite score of 95 means its overall natural hazard risk is higher than 95% of US counties.