Union County, Ohio Natural Disaster Risk
FEMA National Risk Index assessment · OH
Very LowComposite Risk Score
National percentile: 33th
Union County faces very low composite natural disaster risk (NRI Risk Index score 32.7, 33th national percentile), driven primarily by ice storm and hail exposure. Expected annual loss across all 18 hazard types is $19M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Union County carries a very low composite natural disaster risk, with a National Risk Index score of 32.7 out of 100 — placing it in the 33rd 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.
The county's risk is driven primarily by ice storm (freezing rain that coats surfaces in heavy, damaging ice) at Medium risk — $524K in expected annual loss and about 0.69 events per year; hail (ice stones from severe thunderstorms that damage property and crops) at Low risk — $722K in expected annual loss and about 3.48 events per year; and winter weather (heavy snow, blizzards, and hazardous winter conditions) at Low risk — $155K in expected annual loss and about 11.63 events per year. Across all hazards, FEMA estimates $19M in expected annual loss for a population of 62K.
Beyond physical exposure, Union County has a very low social vulnerability rating (how susceptible the population is to harm) and a very 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.
History supports the rating: Union County has received 13 federal disaster declarations since 1978, including 6 for severe storm events and 3 for snowstorm events. The most recent was Tornadoes (tornado), declared in May 2024.
Among 88 Ohio counties, Union County ranks #72 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Ice Storm | Medium | 0.69 / yr | $524K |
| Hail | Low | 3.48 / yr | $722K |
| Winter Weather | Low | 11.63 / yr | $155K |
| Riverine Flood | Low | 1.50 / yr | $13M |
| Tornado | Low | 0.28 / yr | $2M |
| Heat Wave | Low | 3.58 / yr | $647K |
| Earthquake | Very Low | 0.00 / yr | $459K |
| Lightning | Low | 44.66 / yr | $255K |
| Drought | Low | 0.34 / yr | $78K |
| Strong Wind | Low | 2.39 / yr | $588K |
| Landslide | Very Low | 0.07 / yr | $364 |
| Hurricane | Very Low | 0.01 / yr | $14K |
| Cold Wave | Very Low | 4.79 / yr | $467K |
| Wildfire | Very Low | 0.00 / yr | $2K |
| 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
Union County has received 13 federal disaster declarations since 1978, most recently Tornadoes in May 2024. Most frequent causes: Severe Storm (6), Snowstorm (3), Biological (2).
| Declared | Type | Disaster |
|---|---|---|
| May 2024 | Tornado | Tornadoes |
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| June 2012 | Severe Storm | Severe Storms |
| October 2008 | Severe Storm | Severe Wind Storm Associated with Tropical Depression Ike |
| April 2008 | Snowstorm | Record Snow and Near Record Snow |
| September 2005 | Hurricane | Hurricane Katrina Evacuation |
| February 2005 | Severe Storm | Severe Winter Storms, Flooding, and Mudslides |
| January 2005 | Snowstorm | Snow |
| September 2004 | Severe Storm | Severe Storms and Flooding |
Showing the 10 most recent of 13 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 32.7 out of 100, placing it in the Very Low category and the 33th 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 Ice Storm (Medium, $524K EAL), Hail (Low, $722K EAL), Winter Weather (Low, $155K EAL). These account for most of the county's expected annual losses.
How does Union County compare to other Ohio counties?
Union County ranks #72 of 88 Ohio counties for overall natural disaster risk, with a very low rating.
How many federally declared disasters has Union County had?
FEMA records 13 federal disaster declarations for Union County since 1978, most often 6 for severe storm events and 3 for snowstorm events. The most recent was Tornadoes, declared in May 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 $19M EAL is a statistical average, not a guarantee for any specific year or address.