Philadelphia County
Pennsylvania — Natural Disaster Risk Assessment
Very HighComposite Risk Score
National percentile: 100th
Philadelphia County faces very high composite natural disaster risk (NRI Risk Index score 99.6, 100th national percentile), driven primarily by heat wave and cold wave exposure. Expected annual loss across all 18 hazard types is $667M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Top Hazards
All 18 Hazard Risks
| Heat Wave | Very High | 11.07 / yr | $256M |
| Cold Wave | Very High | 0.79 / yr | $57M |
| Winter Weather | Very High | 10.54 / yr | $2M |
| Riverine Flood | Very High | 5.82 / yr | $266M |
| Tornado | High | 0.07 / yr | $21M |
| Earthquake | High | 0.00 / yr | $42M |
| Strong Wind | High | 7.04 / yr | $4M |
| Lightning | High | 35.74 / yr | $2M |
| Hail | High | 2.51 / yr | $2M |
| Hurricane | High | 0.09 / yr | $12M |
| Ice Storm | High | 1.44 / yr | $989K |
| Coastal Flood | High | 3.69 / yr | $3M |
| Landslide | Low | 0.06 / yr | $7K |
| Wildfire | Very Low | 0.00 / yr | $9K |
| Drought | Very Low | 5.76 / yr | $4K |
| Avalanche | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
| Volcanic Activity | Very Low | 0.00 / yr | $0 |
Frequently Asked Questions
What is the overall natural disaster risk for Philadelphia County?
Philadelphia County has a composite FEMA National Risk Index score of 99.6 out of 100, placing it in the Very High category and the 100th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Philadelphia County?
The three highest-rated hazards are Heat Wave (Very High, $256M EAL), Cold Wave (Very High, $57M EAL), Winter Weather (Very High, $2M EAL). These account for most of the county's expected annual losses.
How does Philadelphia County compare to other Pennsylvania counties?
Philadelphia County ranks #1 of 67 Pennsylvania counties for overall natural disaster risk, with a very high rating.
What does Expected Annual Loss (EAL) mean?
EAL is FEMA's estimate of average annual dollar losses from natural hazards, calculated from historical event data and exposure models. Philadelphia County's $667M EAL is a statistical average, not a guarantee for any specific year or address.