Defiance County, Ohio Natural Disaster Risk
FEMA National Risk Index assessment · OH
Very LowComposite Risk Score
National percentile: 42th
Defiance County faces very low composite natural disaster risk (NRI Risk Index score 41.9, 42th national percentile), driven primarily by hail and tornado exposure. Expected annual loss across all 18 hazard types is $16M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Defiance County carries a very low composite natural disaster risk, with a National Risk Index score of 41.9 out of 100 — placing it in the 42nd 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 hail (ice stones from severe thunderstorms that damage property and crops) at Low risk — $537K in expected annual loss and about 3.35 events per year; tornado (violently rotating columns of air capable of catastrophic local damage) at Low risk — $2M in expected annual loss and about 0.22 events per year; and riverine flood (rivers and streams overflowing their banks after heavy rain or snowmelt) at Low risk — $11M in expected annual loss and about 0.50 events per year. Across all hazards, FEMA estimates $16M in expected annual loss for a population of 38K.
Beyond physical exposure, Defiance 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.
The federal record bears this out: Defiance County has received 8 federal disaster declarations since 1977, including 2 for biological events and 2 for severe storm events. The most recent was Covid-19 Pandemic (biological), declared in March 2020.
Among 88 Ohio counties, Defiance County ranks #63 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Hail | Low | 3.35 / yr | $537K |
| Tornado | Low | 0.22 / yr | $2M |
| Riverine Flood | Low | 0.50 / yr | $11M |
| Ice Storm | Low | 1.44 / yr | $125K |
| Strong Wind | Medium | 4.36 / yr | $730K |
| Earthquake | Very Low | 0.00 / yr | $378K |
| Landslide | Very Low | 0.07 / yr | $837 |
| Cold Wave | Low | 3.32 / yr | $544K |
| Lightning | Low | 39.20 / yr | $136K |
| Winter Weather | Low | 10.00 / yr | $37K |
| Drought | Very Low | 0.41 / yr | $21K |
| Heat Wave | Very Low | 4.32 / yr | $138K |
| Hurricane | Very Low | 0.01 / yr | $13K |
| Wildfire | Very Low | 0.00 / yr | $3K |
| 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
Defiance County has received 8 federal disaster declarations since 1977, most recently Covid-19 Pandemic in March 2020. Most frequent causes: Biological (2), Severe Storm (2), Snowstorm (2).
| Declared | Type | Disaster |
|---|---|---|
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| June 2012 | Severe Storm | Severe Storms |
| September 2005 | Hurricane | Hurricane Katrina Evacuation |
| September 2004 | Severe Storm | Severe Storms and Flooding |
| March 1982 | Flood | Severe Storms & Flooding |
| January 1978 | Snowstorm | Blizzards & Snowstorms |
| February 1977 | Snowstorm | Snowstorms |
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Defiance County?
Defiance County has a composite FEMA National Risk Index score of 41.9 out of 100, placing it in the Very Low category and the 42th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Defiance County?
The three highest-rated hazards are Hail (Low, $537K EAL), Tornado (Low, $2M EAL), Riverine Flood (Low, $11M EAL). These account for most of the county's expected annual losses.
How does Defiance County compare to other Ohio counties?
Defiance County ranks #63 of 88 Ohio counties for overall natural disaster risk, with a very low rating.
How many federally declared disasters has Defiance County had?
FEMA records 8 federal disaster declarations for Defiance County since 1977, most often 2 for biological events and 2 for severe storm 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. Defiance County's $16M EAL is a statistical average, not a guarantee for any specific year or address.