Delaware County, PA
FEMA National Risk Index scores, disaster declarations & hazard data
Delaware County has experienced 24 federally declared disasters since 1965, most recently Remnants Of Hurricane Ida in 2021. Its overall natural hazard risk is rated Relatively Moderate — near the middle compared to other US counties.
Delaware County's highest-rated hazards are winter weather, strong wind, and heat wave, with its top risk rated "Very High" by FEMA's National Risk Index. NOAA records 167 storm events in the county over the past decade.
Past disasters & FEMA designations
A federal disaster declaration officially designates a county for FEMA disaster assistance. Delaware County has been designated in 24 declarations since 1965, covering 7 disaster types including hurricane (7), flood (6), severe storm (4).
| Year | Type | Event name |
|---|---|---|
| 2021 | Hurricane | Remnants Of Hurricane Ida |
| 2020 | Biological | Covid-19 Pandemic |
| 2020 | Biological | Covid-19 |
| 2014 | Severe Ice Storm | Severe Winter Storm |
| 2013 | Hurricane | Hurricane Sandy |
| 2011 | Flood | Tropical Storm Lee |
| 2011 | Flood | Remnants Of Tropical Storm Lee |
| 2011 | Hurricane | Hurricane Irene |
| 2011 | Hurricane | Hurricane Irene |
| 2010 | Snowstorm | Severe Winter Storms And Snowstorms |
Showing the 10 most recent of 24 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 | 27.7 | 0 | 0 | — |
| Inland Flooding | Relatively High | 94.4 | 113 | 0 | $30.4M |
| Coastal Flooding | Relatively Moderate | 63.6 | 12 | 0 | — |
| Earthquake | Relatively Moderate | 94.5 | — | — | — |
| Heat Wave | Relatively High | 97.6 | 14 | 0 | — |
| Tornado | Relatively High | 92.5 | 1 | 0 | — |
| Hurricane | Relatively Moderate | 88.1 | 0 | 0 | — |
| Hail | Very Low | 13.3 | 26 | 0 | — |
| Strong Wind | Relatively High | 97.7 | 0 | 0 | — |
| Winter Weather | Very High | 99.2 | 0 | 0 | — |
| Ice Storm | Relatively High | 87 | — | — | — |
| Cold Wave | Relatively High | 91.5 | — | — | — |
| Lightning | Relatively High | 95.6 | 1 | 0 | $1K |
| Drought | Relatively Low | 54.2 | 0 | 0 | — |
| Landslide | Very Low | 59.4 | 0 | 0 | — |
| Avalanche | Very Low | 11.4 | — | — | — |
| 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
Delaware County ranks in the 57th 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 | 57th | Moderate |
| Socioeconomic status | 39th | Low |
| Household characteristics | 45th | Low |
| Racial & ethnic minority status | 73rd | Moderate |
| Housing type & transportation | 76th | High |
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 | 17th | Very Low |
| Risk to homes | 18th | Very Low |
| Buildings in direct exposure zone | 29.1% | — |
NOAA tracked 167 weather events in this county over 2016–2025: 81 in 2016–20 vs 86 in 2021–25 (+6% — relatively stable).
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 Delaware County?
According to the FEMA National Risk Index, the highest-risk hazards in Delaware County, Pennsylvania are winter weather, strong wind, and heat wave. The county's overall natural hazard risk is rated Relatively Moderate — near the middle compared to other US counties.
Has Delaware County received federal disaster declarations?
Yes. Delaware County has received 24 federal disaster declarations since 1965, including declarations in 2021. The most common disaster type on record is hurricane (7 declarations).
Has Delaware County had any FEMA disaster declarations in 2024, 2025, or 2026?
No federal disaster declarations have been recorded for Delaware County since the start of 2024. Its most recent declaration on record is Remnants Of Hurricane Ida in 2021.
How does Delaware County's natural hazard risk compare to nearby counties?
Among neighboring counties, Philadelphia County, PA has the highest overall natural hazard risk (Very High) and Salem County, NJ has the lowest (Relatively Low). Delaware County is rated Relatively Moderate overall.
How is Delaware County's composite disaster risk index calculated?
Delaware 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. Delaware County's composite score of 93 means its overall natural hazard risk is higher than 93% of US counties.