Delaware County Disaster Risk
Delaware County, Pennsylvania
FEMA Risk Rating
Relatively Moderate
National Percentile
93th
of 3,144 counties
State Rank
#7
of 67 (1 = highest risk)
Flood Risk
94th
percentile
Hazard Risk Breakdown
Flood
River, coastal, and surface flooding risk
Relatively High
Higher than 94% of US counties
Wildfire
Wildland and wildland-urban interface fire risk
Very Low
Higher than 28% of US counties
Tornado
Tornado and severe thunderstorm risk
Moderate
Higher than 92% of US counties
Earthquake
Seismic activity and ground shaking risk
Relatively High
Higher than 94% of US counties
Hurricane
Tropical cyclone and hurricane risk
Moderate
Higher than 88% of US counties
Risk Overview
About Natural Disaster Risk in Delaware County, Pennsylvania
Delaware ranks among highest-risk U.S. counties
A composite risk score of 92.91 places Delaware in the national top percentile for natural disaster exposure, earning a Relatively Moderate rating. The county faces exceptionally high risk across flood (94.43), tornado (92.49), earthquake (94.47), and hurricane (88.11) categories.
Pennsylvania's most disaster-prone county
Delaware's 92.91 score represents the highest composite risk in Pennsylvania, substantially exceeding the state average of 67.45 and narrowly surpassing even Dauphin County. This distinction reflects the county's southeastern location, urban density, seismic zone proximity, and exposure to tropical systems and severe convection.
Risk tier above all surrounding counties
Delaware (92.91) dramatically exceeds neighboring counties like Dauphin (91.06) to the west and counties further north, establishing itself as Pennsylvania's premier disaster-risk zone. The county's high population density compounds these natural hazards, creating greater potential community impact from any single event.
Earthquakes, floods, and tornadoes converge
Earthquake risk of 94.47 and flood risk of 94.43 represent Delaware's two primary threats—both at critically elevated levels—while tornado risk of 92.49 adds severe convective danger. The county sits at a convergence of geological and meteorological hazard zones that few other Pennsylvania locations experience simultaneously.
Triple-layer disaster protection strategy required
Flood insurance is essential at 94.43 risk; pair it immediately with earthquake coverage given the 94.47 seismic exposure—these two hazards alone justify comprehensive coverage. Strengthen your home's structural integrity for tornadoes (92.49 risk), establish a family communication plan, and maintain a 30-day emergency supply kit given Delaware's highest-in-state hazard concentration.
Source: FEMA National Risk Index · Narrative reviewed by Evan Brooks, Data Editor
Preparedness Guide
What to Prepare for in Delaware County
Top Hazards by Exposure
Source: FEMA National Risk Index v1.19.0 · Percentiles are national (3,144 counties)
Risk Advisory: Delaware County
Risk Verdict
FEMA's National Risk Index rates Delaware County at the 93th percentile nationally — above average and worth proactive preparation. Residents should prioritize a formal household emergency plan, including evacuation routes, insurance review, and a well-stocked emergency kit.
Hazard Breakdown
Earthquake risk is Delaware County's dominant natural hazard, ranked at the 94th percentile nationally under FEMA's National Risk Index. Flood ranks second at the 94th percentile nationally. Additional tracked hazards include tornado (92th percentile), hurricane (88th percentile), wildfire (28th percentile).
Preparedness Context
Earthquake exposure at the 94th percentile nationally puts Delaware County in a zone where utilities — gas, water, electrical — are the most common post-quake hazard. Knowing how to shut off the main gas valve is an important household skill to develop before an event occurs. Alongside earthquake exposure, Delaware County's flood risk at the 94th percentile nationally reinforces the value of maintaining a household emergency supply cache usable for multiple hazard scenarios. Delaware County households benefit from keeping shoes and a flashlight near the bed — post-earthquake navigation through debris in the dark is a common cause of secondary injury. This low-cost step has outsized protective value.
Regional Context
Delaware County is 25.5 composite risk points above the Pennsylvania average, indicating that residents face greater natural hazard exposure than most of their in-state neighbors.
Is your household prepared for Delaware County's hazards?
Review FEMA's county-specific preparedness checklists and emergency planning guides.
Frequently Asked Questions
What is the natural disaster risk in Delaware County, PA?
What types of natural hazards affect Delaware County?
How does Delaware County risk compare to the Pennsylvania average?
Is Delaware County at risk for earthquake?
How is natural disaster risk measured?
Why is Delaware County higher risk than average?
Data Source
Risk data sourced from the FEMA National Risk Index (NRI). Risk scores are relative rankings (0–100) across all US counties — not absolute risk measures. Higher scores indicate higher relative risk compared to other counties.
Disclaimer: This data is informational only. It is not financial, insurance, or legal advice. Always consult a qualified professional before making insurance or real estate decisions.