Harrison County, Missouri Natural Disaster Risk
FEMA National Risk Index assessment · MO
Very LowComposite Risk Score
National percentile: 29th
Harrison County faces very low composite natural disaster risk (NRI Risk Index score 29.3, 29th national percentile), driven primarily by drought and landslide exposure. Expected annual loss across all 18 hazard types is $7M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Overall natural disaster risk in Harrison County is very low, with a National Risk Index score of 29.3 out of 100 — placing it in the 29th 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 drought (extended dry periods that stress water supplies and agriculture) at High risk — $1M in expected annual loss and about 17.41 events per year; landslide (downhill movement of rock, soil, and debris on unstable slopes) at Low risk — $7K in expected annual loss and about 0.40 events per year; and heat wave (prolonged periods of extreme heat that threaten health and infrastructure) at Low risk — $592K in expected annual loss and about 8.79 events per year. Across all hazards, FEMA estimates $7M in expected annual loss for a population of 8K.
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 federal record bears this out: Harrison County has received 18 federal disaster declarations since 1973, including 9 for severe storm events and 3 for severe ice storm events. The most recent was Covid-19 Pandemic (biological), declared in March 2020.
Among 115 Missouri counties, Harrison County ranks #86 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Drought | High | 17.41 / yr | $1M |
| Landslide | Low | 0.40 / yr | $7K |
| Heat Wave | Low | 8.79 / yr | $592K |
| Wildfire | Very Low | 0.00 / yr | $63K |
| Tornado | Low | 0.43 / yr | $1M |
| Hail | Low | 4.65 / yr | $249K |
| Cold Wave | Low | 4.74 / yr | $803K |
| Strong Wind | Low | 3.50 / yr | $354K |
| Winter Weather | Low | 11.74 / yr | $26K |
| Riverine Flood | Very Low | 0.50 / yr | $2M |
| Earthquake | Very Low | 0.00 / yr | $36K |
| Lightning | Very Low | 46.60 / yr | $54K |
| Ice Storm | Very Low | 0.30 / yr | $11K |
| Hurricane | Very Low | 0.01 / 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
Harrison County has received 18 federal disaster declarations since 1973, most recently Covid-19 Pandemic in March 2020. Most frequent causes: Severe Storm (9), Severe Ice Storm (3), Biological (2).
| Declared | Type | Disaster |
|---|---|---|
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| July 2019 | Severe Storm | Severe Storms, Tornadoes, and Flooding |
| August 2015 | Severe Storm | Severe Storms, Tornadoes, Straight-Line Winds, and Flooding |
| October 2014 | Severe Storm | Severe Storms, Tornadoes, Straight-Line Winds, and Flooding |
| February 2011 | Severe Storm | Severe Winter Storm |
| August 2010 | Severe Storm | Severe Storms, Flooding, and Tornadoes |
| January 2009 | Severe Ice Storm | Severe Winter Storm |
| June 2008 | Severe Storm | Severe Storms and Flooding |
| December 2007 | Severe Ice Storm | Severe Winter Storms |
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 29.3 out of 100, placing it in the Very Low category and the 29th 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 Drought (High, $1M EAL), Landslide (Low, $7K EAL), Heat Wave (Low, $592K EAL). These account for most of the county's expected annual losses.
How does Harrison County compare to other Missouri counties?
Harrison County ranks #86 of 115 Missouri 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 1973, most often 9 for severe storm events and 3 for severe ice 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. Harrison County's $7M EAL is a statistical average, not a guarantee for any specific year or address.