Adams County, Pennsylvania Natural Disaster Risk
FEMA National Risk Index assessment · PA
LowComposite Risk Score
National percentile: 68th
Adams County faces low composite natural disaster risk (NRI Risk Index score 67.5, 68th national percentile), driven primarily by drought and hurricane exposure. Expected annual loss across all 18 hazard types is $27M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
FEMA's National Risk Index rates Adams County at low composite risk, with a National Risk Index score of 67.5 out of 100 — placing it in the 68th 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.
Most of Adams County's expected losses come from drought (extended dry periods that stress water supplies and agriculture) at Medium risk — $1M in expected annual loss and about 3.26 events per year; hurricane (tropical cyclones bringing extreme wind, rain, and storm surge) at Medium risk — $3M in expected annual loss and about 0.08 events per year; and riverine flood (rivers and streams overflowing their banks after heavy rain or snowmelt) at Medium risk — $17M in expected annual loss and about 1.64 events per year. Across all hazards, FEMA estimates $27M in expected annual loss for a population of 104K.
Beyond physical exposure, Adams County has a low 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). A less vulnerable population paired with strong resilience helps the community absorb and recover from events.
The county's disaster history tells the same story: Adams County has received 20 federal disaster declarations since 1972, including 7 for flood events and 4 for snowstorm events. The most recent was Covid-19 Pandemic (biological), declared in March 2020.
Among 67 Pennsylvania counties, Adams County ranks #37 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Drought | Medium | 3.26 / yr | $1M |
| Hurricane | Medium | 0.08 / yr | $3M |
| Riverine Flood | Medium | 1.64 / yr | $17M |
| Strong Wind | Medium | 6.55 / yr | $1M |
| Earthquake | Low | 0.00 / yr | $977K |
| Winter Weather | Medium | 11.84 / yr | $141K |
| Heat Wave | Low | 4.79 / yr | $882K |
| Lightning | Low | 37.28 / yr | $301K |
| Ice Storm | Low | 0.92 / yr | $74K |
| Tornado | Low | 0.32 / yr | $1M |
| Wildfire | Very Low | 0.00 / yr | $34K |
| Landslide | Very Low | 0.22 / yr | $643 |
| Hail | Very Low | 3.08 / yr | $137K |
| Cold Wave | Low | 1.16 / yr | $363K |
| Avalanche | Very Low | 0.00 / yr | $0 |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
| Volcanic Activity | Very Low | 0.00 / yr | $0 |
Disaster History
Adams County has received 20 federal disaster declarations since 1972, most recently Covid-19 Pandemic in March 2020. Most frequent causes: Flood (7), Snowstorm (4), Severe Storm (4).
| Declared | Type | Disaster |
|---|---|---|
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| March 2016 | Snowstorm | Severe Winter Storm and Snowstorm |
| October 2012 | Hurricane | Hurricane Sandy |
| September 2011 | Flood | Tropical Storm Lee |
| September 2011 | Flood | Remnants of Tropical Storm Lee |
| April 2010 | Snowstorm | Severe Winter Storms and Snowstorms |
| June 2006 | Severe Storm | Severe Storms, Flooding, and Mudslides |
| September 2005 | Hurricane | Hurricane Katrina |
| September 2004 | Severe Storm | Severe Storms and Flooding Associated with Tropical Depression Frances |
Showing the 10 most recent of 20 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Adams County?
Adams County has a composite FEMA National Risk Index score of 67.5 out of 100, placing it in the Low category and the 68th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Adams County?
The three highest-rated hazards are Drought (Medium, $1M EAL), Hurricane (Medium, $3M EAL), Riverine Flood (Medium, $17M EAL). These account for most of the county's expected annual losses.
How does Adams County compare to other Pennsylvania counties?
Adams County ranks #37 of 67 Pennsylvania counties for overall natural disaster risk, with a low rating.
How many federally declared disasters has Adams County had?
FEMA records 20 federal disaster declarations for Adams County since 1972, most often 7 for flood events and 4 for snowstorm events. The most recent was Covid-19 Pandemic, declared in March 2020.
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. Adams County's $27M EAL is a statistical average, not a guarantee for any specific year or address.