Brown County, Ohio Natural Disaster Risk
FEMA National Risk Index assessment · OH
LowComposite Risk Score
National percentile: 63th
Brown County faces low composite natural disaster risk (NRI Risk Index score 62.6, 63th national percentile), driven primarily by landslide and strong wind exposure. Expected annual loss across all 18 hazard types is $18M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Brown County carries a low composite natural disaster risk, with a National Risk Index score of 62.6 out of 100 — placing it in the 63rd 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 Brown County's expected losses come from landslide (downhill movement of rock, soil, and debris on unstable slopes) at Low risk — $26K in expected annual loss and about 0.25 events per year; strong wind (damaging straight-line winds outside of tornadoes and hurricanes) at High risk — $1M in expected annual loss and about 2.70 events per year; and lightning (electrical discharges from storms that ignite fires and cause casualties) at Medium risk — $472K in expected annual loss and about 49.52 events per year. Across all hazards, FEMA estimates $18M in expected annual loss for a population of 44K.
Beyond physical exposure, Brown 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 federal record bears this out: Brown County has received 19 federal disaster declarations since 1968, including 7 for severe storm events and 5 for flood events. The most recent was Covid-19 Pandemic (biological), declared in March 2020.
Among 88 Ohio counties, Brown County ranks #36 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Landslide | Low | 0.25 / yr | $26K |
| Strong Wind | High | 2.70 / yr | $1M |
| Lightning | Medium | 49.52 / yr | $472K |
| Riverine Flood | Medium | 2.50 / yr | $13M |
| Earthquake | Low | 0.00 / yr | $490K |
| Heat Wave | Low | 5.95 / yr | $564K |
| Ice Storm | Medium | 0.87 / yr | $129K |
| Wildfire | Very Low | 0.00 / yr | $68K |
| Tornado | Low | 0.26 / yr | $1M |
| Drought | Low | 2.25 / yr | $140K |
| Winter Weather | Low | 11.37 / yr | $53K |
| Cold Wave | Low | 1.84 / yr | $659K |
| Hail | Low | 3.19 / yr | $136K |
| Hurricane | Very Low | 0.01 / yr | $9K |
| 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
Brown County has received 19 federal disaster declarations since 1968, most recently Covid-19 Pandemic in March 2020. Most frequent causes: Severe Storm (7), Flood (5), Snowstorm (3).
| Declared | Type | Disaster |
|---|---|---|
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| April 2019 | Flood | Severe Storms, Flooding, and Landslides |
| April 2018 | Flood | Severe Storms, Landslides, and Mudslides |
| June 2012 | Severe Storm | Severe Storms |
| July 2011 | Severe Storm | Severe Storms and Flooding |
| 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 |
Showing the 10 most recent of 19 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Brown County?
Brown County has a composite FEMA National Risk Index score of 62.6 out of 100, placing it in the Low category and the 63th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Brown County?
The three highest-rated hazards are Landslide (Low, $26K EAL), Strong Wind (High, $1M EAL), Lightning (Medium, $472K EAL). These account for most of the county's expected annual losses.
How does Brown County compare to other Ohio counties?
Brown County ranks #36 of 88 Ohio counties for overall natural disaster risk, with a low rating.
How many federally declared disasters has Brown County had?
FEMA records 19 federal disaster declarations for Brown County since 1968, most often 7 for severe storm events and 5 for flood 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. Brown County's $18M EAL is a statistical average, not a guarantee for any specific year or address.