Philadelphia County, PA
FEMA National Risk Index scores, disaster declarations & hazard data
Philadelphia County has experienced 25 federally declared disasters since 1965, most recently Remnants Of Hurricane Ida in 2021. Its overall natural hazard risk is rated Very High — among the most at-risk counties in the country.
Philadelphia County's highest-rated hazards are heat wave, cold wave, and winter weather, with its top risk rated "Very High" by FEMA's National Risk Index. Recorded storm events have increased 21% over the past five years compared to the prior five-year period. Community vulnerability is elevated (95th percentile nationally), suggesting residents may face greater difficulty recovering from major disasters.
Past disasters & FEMA designations
A federal disaster declaration officially designates a county for FEMA disaster assistance. Philadelphia County has been designated in 25 declarations since 1965, covering 7 disaster types including hurricane (8), flood (5), snowstorm (4).
| Year | Type | Event name |
|---|---|---|
| 2021 | Hurricane | Remnants Of Hurricane Ida |
| 2020 | Biological | Covid-19 Pandemic |
| 2020 | Biological | Covid-19 |
| 2016 | Snowstorm | Severe Winter Storm And Snowstorm |
| 2014 | Severe Ice Storm | Severe Winter Storm |
| 2013 | Hurricane | Hurricane Sandy |
| 2013 | Hurricane | Hurricane Sandy |
| 2011 | Flood | Tropical Storm Lee |
| 2011 | Flood | Remnants Of Tropical Storm Lee |
| 2011 | Hurricane | Hurricane Irene |
Showing the 10 most recent of 25 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 | 28.7 | 0 | 0 | — |
| Inland Flooding | Very High | 99.6 | 101 | 1 | $100.0M |
| Coastal Flooding | Relatively High | 85.4 | 15 | 0 | — |
| Earthquake | Relatively High | 98.3 | — | — | — |
| Heat Wave | Very High | 100 | 20 | 12 | — |
| Tornado | Relatively High | 98.7 | 3 | 0 | — |
| Hurricane | Relatively High | 94.3 | 0 | 0 | — |
| Hail | Relatively High | 95.1 | 16 | 0 | — |
| Strong Wind | Relatively High | 97.9 | 0 | 0 | — |
| Winter Weather | Very High | 99.8 | 0 | 0 | — |
| Ice Storm | Relatively High | 94.2 | — | — | — |
| Cold Wave | Very High | 99.8 | — | — | — |
| Lightning | Relatively High | 96.2 | 0 | 0 | — |
| Drought | Very Low | 21.7 | 0 | 0 | — |
| Landslide | Relatively Low | 76.3 | 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
Philadelphia County ranks in the 95th percentile (High) 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 | 95th | High |
| Socioeconomic status | 91st | High |
| Household characteristics | 84th | High |
| Racial & ethnic minority status | 95th | High |
| Housing type & transportation | 92nd | 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 | 20th | Relatively Low |
| Risk to homes | 20th | Relatively Low |
| Buildings in direct exposure zone | 2.8% | — |
NOAA tracked 155 weather events in this county over 2016–2025: 70 in 2016–20 vs 85 in 2021–25 (+21% — frequency increasing).
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 Philadelphia County?
According to the FEMA National Risk Index, the highest-risk hazards in Philadelphia County, Pennsylvania are heat wave, cold wave, and winter weather. The county's overall natural hazard risk is rated Very High — among the most at-risk counties in the country.
Has Philadelphia County received federal disaster declarations?
Yes. Philadelphia County has received 25 federal disaster declarations since 1965, including declarations in 2021. The most common disaster type on record is hurricane (8 declarations).
Has Philadelphia County had any FEMA disaster declarations in 2024, 2025, or 2026?
No federal disaster declarations have been recorded for Philadelphia County since the start of 2024. Its most recent declaration on record is Remnants Of Hurricane Ida in 2021.
How does Philadelphia County's natural hazard risk compare to nearby counties?
Among neighboring counties, Montgomery County, PA has the highest overall natural hazard risk (Relatively High) and Gloucester County, NJ has the lowest (Relatively Moderate). Philadelphia County is rated Very High overall.
How is Philadelphia County's composite disaster risk index calculated?
Philadelphia 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. Philadelphia County's composite score of 100 means its overall natural hazard risk is higher than 100% of US counties.