Delaware County
Pennsylvania — Natural Disaster Risk Assessment
MediumComposite Risk Score
National percentile: 93th
Delaware County faces medium composite natural disaster risk (NRI Risk Index score 92.9, 93th national percentile), driven primarily by winter weather and strong wind exposure. Expected annual loss across all 18 hazard types is $135M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Top Hazards
All 18 Hazard Risks
| Winter Weather | Very High | 10.49 / yr | $2M |
| Strong Wind | High | 6.94 / yr | $5M |
| Heat Wave | High | 11.06 / yr | $13M |
| Lightning | High | 35.98 / yr | $2M |
| Earthquake | Medium | 0.00 / yr | $13M |
| Riverine Flood | High | 4.64 / yr | $74M |
| Tornado | High | 0.10 / yr | $9M |
| Cold Wave | High | 0.79 / yr | $9M |
| Hurricane | Medium | 0.09 / yr | $6M |
| Ice Storm | High | 1.41 / yr | $750K |
| Coastal Flood | Medium | 3.69 / yr | $730K |
| Landslide | Very Low | 0.16 / yr | $3K |
| Drought | Low | 5.71 / yr | $209K |
| Wildfire | Very Low | 0.00 / yr | $13K |
| Hail | Very Low | 2.47 / yr | $46K |
| Avalanche | Very Low | 0.01 / yr | $11 |
| 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 Delaware County?
Delaware County has a composite FEMA National Risk Index score of 92.9 out of 100, placing it in the Medium category and the 93th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Delaware County?
The three highest-rated hazards are Winter Weather (Very High, $2M EAL), Strong Wind (High, $5M EAL), Heat Wave (High, $13M EAL). These account for most of the county's expected annual losses.
How does Delaware County compare to other Pennsylvania counties?
Delaware County ranks #7 of 67 Pennsylvania counties for overall natural disaster risk, with a medium 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. Delaware County's $135M EAL is a statistical average, not a guarantee for any specific year or address.