Philadelphia County Disaster Risk
Philadelphia County, Pennsylvania
FEMA Risk Rating
Very High
National Percentile
100th
of 3,144 counties
State Rank
#1
of 67 (1 = highest risk)
Flood Risk
100th
percentile
Hazard Risk Breakdown
Flood
River, coastal, and surface flooding risk
Very High
Higher than 100% of US counties
Wildfire
Wildland and wildland-urban interface fire risk
Very Low
Higher than 29% of US counties
Tornado
Tornado and severe thunderstorm risk
Relatively High
Higher than 99% of US counties
Earthquake
Seismic activity and ground shaking risk
Relatively High
Higher than 98% of US counties
Hurricane
Tropical cyclone and hurricane risk
Moderate
Higher than 94% of US counties
Risk Overview
About Natural Disaster Risk in Philadelphia County, Pennsylvania
Philadelphia faces very high disaster risk nationally
Philadelphia County's composite risk score of 99.59 ranks it among the highest-risk counties in the United States, vastly exceeding Pennsylvania's state average of 67.45. The county faces extreme exposure across nearly every hazard category: floods (99.59), tornadoes (98.66), earthquakes (98.28), and hurricanes (94.28).
Pennsylvania's highest-risk county by far
Philadelphia County dramatically exceeds all other Pennsylvania counties in disaster risk, with a score nearly 32 points higher than the state average. No other county in Pennsylvania approaches Philadelphia's multifaceted hazard exposure, making it uniquely vulnerable on the state stage.
Vastly riskier than surrounding counties
Philadelphia's risk profile is incomparable to nearby Bucks, Chester, and Delaware counties, which all score significantly lower. The urban density, river systems, and coastal storm exposure that define Philadelphia create hazard conditions fundamentally different from its suburban and rural neighbors.
Floods, tornadoes, and quakes all major threats
Philadelphia faces an unprecedented convergence of hazards: flood risk (99.59) from the Delaware River and urban stormwater vulnerability, tornado risk (98.66) from Atlantic systems, and earthquake risk (98.28) from regional fault lines. Hurricane impacts (94.28) add an additional layer of coastal and inland wind damage exposure.
Comprehensive coverage is non-negotiable
Philadelphia residents must secure flood insurance immediately—it's essential given the 99.59 flood risk and not covered by standard homeowners policies. Additionally, ensure your policy includes robust wind and earthquake coverage, and consider umbrella liability insurance given the county's extreme multi-hazard exposure.
Source: FEMA National Risk Index · Narrative reviewed by Evan Brooks, Data Editor
Preparedness Guide
What to Prepare for in Philadelphia County
Top Hazards by Exposure
Source: FEMA National Risk Index v1.19.0 · Percentiles are national (3,144 counties)
Risk Advisory: Philadelphia County
Risk Verdict
Philadelphia County's composite risk score at the 100th percentile nationally reflects extreme multi-hazard exposure that demands active preparedness. Residents should prioritize a formal household emergency plan, including evacuation routes, insurance review, and a well-stocked emergency kit.
Hazard Breakdown
Flood risk is Philadelphia County's dominant natural hazard, ranked at the 100th percentile nationally under FEMA's National Risk Index. Tornado ranks second at the 99th percentile nationally. Additional tracked hazards include earthquake (98th percentile), hurricane (94th percentile), wildfire (29th percentile).
Preparedness Context
Flood risk is Philadelphia County's top hazard at the 100th percentile nationally. Households in or near designated flood zones face elevated financial exposure; flood insurance typically requires a 30-day waiting period before it takes effect, so applying before the season is advisable. Secondary tornado exposure at the 99th percentile adds a second preparedness layer; households should review coverage options and alert sign-up for both hazard types. Households across Philadelphia County should identify the nearest community shelter and keep a basic emergency kit — water, non-perishable food, medications, flashlight, and battery radio — in a location easy to grab quickly.
Regional Context
Philadelphia County is 32.1 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 Philadelphia County's hazards?
Review FEMA's county-specific preparedness checklists and emergency planning guides.
Frequently Asked Questions
What is the natural disaster risk in Philadelphia County, PA?
What types of natural hazards affect Philadelphia County?
How does Philadelphia County risk compare to the Pennsylvania average?
Is Philadelphia County at risk for flooding?
How is natural disaster risk measured?
Why is Philadelphia 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.