Alcorn County, Mississippi Natural Disaster Risk
FEMA National Risk Index assessment · MS
LowComposite Risk Score
National percentile: 65th
Alcorn County faces low composite natural disaster risk (NRI Risk Index score 65.0, 65th national percentile), driven primarily by earthquake and tornado exposure. Expected annual loss across all 18 hazard types is $19M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
FEMA's National Risk Index rates Alcorn County at low composite risk, with a National Risk Index score of 65.0 out of 100 — placing it in the 65th 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.
The county's risk is driven primarily by earthquake (ground shaking from sudden movement along geologic faults) at Low risk — $4M in expected annual loss and about 0.00 events per year; tornado (violently rotating columns of air capable of catastrophic local damage) at Medium risk — $5M in expected annual loss and about 0.29 events per year; and cold wave (prolonged spells of dangerously low temperatures) at Medium risk — $3M in expected annual loss and about 1.26 events per year. Across all hazards, FEMA estimates $19M in expected annual loss for a population of 35K.
Beyond physical exposure, Alcorn County has a high social vulnerability rating (how susceptible the population is to harm) and a 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.
History supports the rating: Alcorn County has received 18 federal disaster declarations since 1973, including 9 for severe storm events and 4 for hurricane events. The most recent was Severe Winter Storm (winter storm), declared in February 2026.
Among 82 Mississippi counties, Alcorn County ranks #24 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Earthquake | Low | 0.00 / yr | $4M |
| Tornado | Medium | 0.29 / yr | $5M |
| Cold Wave | Medium | 1.26 / yr | $3M |
| Heat Wave | Low | 14.63 / yr | $877K |
| Landslide | Low | 0.58 / yr | $3K |
| Lightning | Medium | 61.48 / yr | $275K |
| Hurricane | Very Low | 0.04 / yr | $119K |
| Riverine Flood | Low | 1.39 / yr | $5M |
| Drought | Low | 13.24 / yr | $77K |
| Wildfire | Very Low | 0.00 / yr | $26K |
| Strong Wind | Low | 2.39 / yr | $345K |
| Ice Storm | Low | 0.71 / yr | $36K |
| Hail | Very Low | 3.50 / yr | $97K |
| Winter Weather | Very Low | 4.74 / yr | $11K |
| 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
Alcorn County has received 18 federal disaster declarations since 1973, most recently Severe Winter Storm in February 2026. Most frequent causes: Severe Storm (9), Hurricane (4), Winter Storm (2).
| Declared | Type | Disaster |
|---|---|---|
| February 2026 | Winter Storm | Severe Winter Storm |
| January 2026 | Winter Storm | Severe Winter Storm |
| October 2021 | Hurricane | Hurricane Ida |
| August 2021 | Hurricane | Hurricane Ida |
| April 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| December 2019 | Severe Storm | Severe Storm, Straight-Line Winds, and Flooding |
| April 2019 | Severe Storm | Severe Storms, Straight-Line Winds, Tornadoes, and Flooding |
| April 2011 | Severe Storm | Severe Storms, Tornadoes, Straight-Line Winds, and Associated Flooding |
| May 2010 | Severe Storm | Severe Storms, Tornadoes, and Flooding |
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 Alcorn County?
Alcorn County has a composite FEMA National Risk Index score of 65.0 out of 100, placing it in the Low category and the 65th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Alcorn County?
The three highest-rated hazards are Earthquake (Low, $4M EAL), Tornado (Medium, $5M EAL), Cold Wave (Medium, $3M EAL). These account for most of the county's expected annual losses.
How does Alcorn County compare to other Mississippi counties?
Alcorn County ranks #24 of 82 Mississippi counties for overall natural disaster risk, with a low rating.
How many federally declared disasters has Alcorn County had?
FEMA records 18 federal disaster declarations for Alcorn County since 1973, most often 9 for severe storm events and 4 for hurricane events. The most recent was Severe Winter Storm, declared in February 2026.
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. Alcorn County's $19M EAL is a statistical average, not a guarantee for any specific year or address.