Mercer County, Missouri Natural Disaster Risk
FEMA National Risk Index assessment · MO
Very LowComposite Risk Score
National percentile: 12th
Mercer County faces very low composite natural disaster risk (NRI Risk Index score 12.3, 12th national percentile), driven primarily by landslide and drought exposure. Expected annual loss across all 18 hazard types is $4M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Overall natural disaster risk in Mercer County is very low, with a National Risk Index score of 12.3 out of 100 — placing it in the 12th 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 Mercer County's expected losses come from landslide (downhill movement of rock, soil, and debris on unstable slopes) at Low risk — $11K in expected annual loss and about 0.41 events per year; drought (extended dry periods that stress water supplies and agriculture) at Medium risk — $587K in expected annual loss and about 12.42 events per year; and wildfire (uncontrolled fires that spread across wildland and into communities) at Very Low risk — $32K in expected annual loss and about 0.00 events per year. Across all hazards, FEMA estimates $4M in expected annual loss for a population of 4K.
Beyond physical exposure, Mercer County has a high social vulnerability rating (how susceptible the population is to harm) and a very low 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: Mercer County has received 19 federal disaster declarations since 1973, including 10 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, Mercer County ranks #111 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Landslide | Low | 0.41 / yr | $11K |
| Drought | Medium | 12.42 / yr | $587K |
| Wildfire | Very Low | 0.00 / yr | $32K |
| Heat Wave | Low | 8.53 / yr | $230K |
| Tornado | Low | 0.24 / yr | $755K |
| Hail | Low | 4.08 / yr | $145K |
| Cold Wave | Low | 4.68 / yr | $389K |
| Strong Wind | Low | 3.41 / yr | $138K |
| Riverine Flood | Very Low | 0.39 / yr | $2M |
| Earthquake | Very Low | 0.00 / yr | $16K |
| Winter Weather | Very Low | 10.89 / yr | $11K |
| Hurricane | Very Low | 0.01 / yr | $2K |
| Lightning | Very Low | 46.67 / yr | $23K |
| Ice Storm | Very Low | 0.22 / 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
Mercer County has received 19 federal disaster declarations since 1973, most recently Covid-19 Pandemic in March 2020. Most frequent causes: Severe Storm (10), 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 |
| 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 |
| December 2007 | Severe Ice Storm | Severe Winter Storms |
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 Mercer County?
Mercer County has a composite FEMA National Risk Index score of 12.3 out of 100, placing it in the Very Low category and the 12th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Mercer County?
The three highest-rated hazards are Landslide (Low, $11K EAL), Drought (Medium, $587K EAL), Wildfire (Very Low, $32K EAL). These account for most of the county's expected annual losses.
How does Mercer County compare to other Missouri counties?
Mercer County ranks #111 of 115 Missouri counties for overall natural disaster risk, with a very low rating.
How many federally declared disasters has Mercer County had?
FEMA records 19 federal disaster declarations for Mercer County since 1973, most often 10 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. Mercer County's $4M EAL is a statistical average, not a guarantee for any specific year or address.