Union County, Pennsylvania Natural Disaster Risk
FEMA National Risk Index assessment · PA
LowComposite Risk Score
National percentile: 55th
Union County faces low composite natural disaster risk (NRI Risk Index score 55.2, 55th national percentile), driven primarily by strong wind and winter weather exposure. Expected annual loss across all 18 hazard types is $14M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Overall natural disaster risk in Union County is low, with a National Risk Index score of 55.2 out of 100 — placing it in the 55th national percentile and below the national average for natural-disaster risk. The score blends Expected Annual Loss, Social Vulnerability, and Community Resilience across all 18 FEMA hazard types.
Risk here concentrates in strong wind (damaging straight-line winds outside of tornadoes and hurricanes) at Medium risk — $1M in expected annual loss and about 3.10 events per year; winter weather (heavy snow, blizzards, and hazardous winter conditions) at Medium risk — $165K in expected annual loss and about 12.81 events per year; and hurricane (tropical cyclones bringing extreme wind, rain, and storm surge) at Low risk — $706K in expected annual loss and about 0.05 events per year. Across all hazards, FEMA estimates $14M in expected annual loss for a population of 43K.
Beyond physical exposure, Union County has a high social vulnerability rating (how susceptible the population is to harm) and a high community resilience rating (its capacity to prepare for and recover from disasters). Higher vulnerability is partly offset by strong community resilience and recovery capacity.
History supports the rating: Union County has received 18 federal disaster declarations since 1972, including 6 for flood events and 3 for hurricane events. The most recent was Tropical Storm Debby (tropical storm), declared in September 2024.
Among 67 Pennsylvania counties, Union County ranks #50 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Strong Wind | Medium | 3.10 / yr | $1M |
| Winter Weather | Medium | 12.81 / yr | $165K |
| Hurricane | Low | 0.05 / yr | $706K |
| Riverine Flood | Low | 1.32 / yr | $11M |
| Landslide | Low | 0.28 / yr | $3K |
| Lightning | Low | 33.70 / yr | $208K |
| Heat Wave | Low | 2.79 / yr | $225K |
| Earthquake | Very Low | 0.00 / yr | $149K |
| Tornado | Low | 0.12 / yr | $499K |
| Avalanche | Very Low | 0.01 / yr | $108 |
| Cold Wave | Very Low | 1.42 / yr | $188K |
| Ice Storm | Very Low | 0.10 / yr | $13K |
| Wildfire | Very Low | 0.00 / yr | $3K |
| Hail | Very Low | 1.57 / yr | $24K |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Drought | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
| Volcanic Activity | Very Low | 0.00 / yr | $0 |
Disaster History
Union County has received 18 federal disaster declarations since 1972, most recently Tropical Storm Debby in September 2024. Most frequent causes: Flood (6), Hurricane (3), Severe Storm (3).
| Declared | Type | Disaster |
|---|---|---|
| September 2024 | Tropical Storm | Tropical Storm Debby |
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| October 2012 | Hurricane | Hurricane Sandy |
| September 2011 | Flood | Tropical Storm Lee |
| September 2011 | Flood | Remnants of Tropical Storm Lee |
| September 2005 | Hurricane | Hurricane Katrina |
| September 2004 | Hurricane | Tropical Depression Ivan |
| September 2004 | Severe Storm | Severe Storms and Flooding Associated with Tropical Depression Frances |
| March 2003 | Severe Storm | Snow |
Showing the 10 most recent of 18 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Union County?
Union County has a composite FEMA National Risk Index score of 55.2 out of 100, placing it in the Low category and the 55th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Union County?
The three highest-rated hazards are Strong Wind (Medium, $1M EAL), Winter Weather (Medium, $165K EAL), Hurricane (Low, $706K EAL). These account for most of the county's expected annual losses.
How does Union County compare to other Pennsylvania counties?
Union County ranks #50 of 67 Pennsylvania counties for overall natural disaster risk, with a low rating.
How many federally declared disasters has Union County had?
FEMA records 18 federal disaster declarations for Union County since 1972, most often 6 for flood events and 3 for hurricane events. The most recent was Tropical Storm Debby, declared in September 2024.
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. Union County's $14M EAL is a statistical average, not a guarantee for any specific year or address.