Harrison County, Ohio Natural Disaster Risk
FEMA National Risk Index assessment · OH
Very LowComposite Risk Score
National percentile: 11th
Harrison County faces very low composite natural disaster risk (NRI Risk Index score 11.4, 11th national percentile), driven primarily by landslide and strong wind exposure. Expected annual loss across all 18 hazard types is $4M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
FEMA's National Risk Index rates Harrison County at very low composite risk, with a National Risk Index score of 11.4 out of 100 — placing it in the 11th national percentile and among the lowest-risk counties in the country. The score blends Expected Annual Loss, Social Vulnerability, and Community Resilience across all 18 FEMA hazard types.
Most of Harrison County's expected losses come from landslide (downhill movement of rock, soil, and debris on unstable slopes) at Low risk — $19K in expected annual loss and about 0.88 events per year; strong wind (damaging straight-line winds outside of tornadoes and hurricanes) at Medium risk — $714K in expected annual loss and about 2.17 events per year; and drought (extended dry periods that stress water supplies and agriculture) at Low risk — $226K in expected annual loss and about 6.16 events per year. Across all hazards, FEMA estimates $4M in expected annual loss for a population of 14K.
Beyond physical exposure, Harrison County has a high social vulnerability rating (how susceptible the population is to harm) and a medium community resilience rating (its capacity to prepare for and recover from disasters). That combination — a more vulnerable population with limited resilience — can amplify the human cost of any given event.
The county's disaster history tells the same story: Harrison County has received 18 federal disaster declarations since 1965, including 10 for severe storm events and 2 for biological events. The most recent was Covid-19 Pandemic (biological), declared in March 2020.
Among 88 Ohio counties, Harrison County ranks #88 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Landslide | Low | 0.88 / yr | $19K |
| Strong Wind | Medium | 2.17 / yr | $714K |
| Drought | Low | 6.16 / yr | $226K |
| Hail | Low | 3.88 / yr | $133K |
| Lightning | Low | 42.05 / yr | $117K |
| Hurricane | Very Low | 0.01 / yr | $16K |
| Riverine Flood | Very Low | 1.36 / yr | $2M |
| Heat Wave | Very Low | 2.05 / yr | $87K |
| Earthquake | Very Low | 0.00 / yr | $31K |
| Ice Storm | Very Low | 0.27 / yr | $14K |
| Tornado | Very Low | 0.16 / yr | $163K |
| Wildfire | Very Low | 0.00 / yr | $5K |
| Winter Weather | Very Low | 9.68 / yr | $9K |
| Cold Wave | Very Low | 2.84 / yr | $40K |
| 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
Harrison County has received 18 federal disaster declarations since 1965, most recently Covid-19 Pandemic in March 2020. Most frequent causes: Severe Storm (10), Biological (2), Snowstorm (2).
| Declared | Type | Disaster |
|---|---|---|
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| April 2018 | Flood | Severe Storms, Landslides, and Mudslides |
| August 2012 | Severe Storm | Severe Storms and Straight-Line Winds |
| June 2012 | Severe Storm | Severe Storms |
| October 2008 | Severe Storm | Severe Wind Storm Associated with Tropical Depression Ike |
| September 2005 | Hurricane | Hurricane Katrina Evacuation |
| February 2005 | Severe Storm | Severe Winter Storms, Flooding, and Mudslides |
| September 2004 | Severe Storm | Severe Storms and Flooding |
| June 2004 | Severe Storm | Severe Storms and Flooding |
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 Harrison County?
Harrison County has a composite FEMA National Risk Index score of 11.4 out of 100, placing it in the Very Low category and the 11th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Harrison County?
The three highest-rated hazards are Landslide (Low, $19K EAL), Strong Wind (Medium, $714K EAL), Drought (Low, $226K EAL). These account for most of the county's expected annual losses.
How does Harrison County compare to other Ohio counties?
Harrison County ranks #88 of 88 Ohio counties for overall natural disaster risk, with a very low rating.
How many federally declared disasters has Harrison County had?
FEMA records 18 federal disaster declarations for Harrison County since 1965, most often 10 for severe storm events and 2 for biological 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. Harrison County's $4M EAL is a statistical average, not a guarantee for any specific year or address.