Marshall County, South Dakota Natural Disaster Risk
FEMA National Risk Index assessment · SD
Very LowComposite Risk Score
National percentile: 14th
Marshall County faces very low composite natural disaster risk (NRI Risk Index score 14.5, 14th national percentile), driven primarily by winter weather and wildfire exposure. Expected annual loss across all 18 hazard types is $6M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Overall natural disaster risk in Marshall County is very low, with a National Risk Index score of 14.5 out of 100 — placing it in the 14th 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 winter weather (heavy snow, blizzards, and hazardous winter conditions) at Medium risk — $216K in expected annual loss and about 22.58 events per year; wildfire (uncontrolled fires that spread across wildland and into communities) at Low risk — $309K in expected annual loss and about 0.00 events per year; and hail (ice stones from severe thunderstorms that damage property and crops) at Low risk — $624K in expected annual loss and about 3.87 events per year. Across all hazards, FEMA estimates $6M in expected annual loss for a population of 4K.
Beyond physical exposure, Marshall County has a low 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). Both measures sit toward the lower end, indicating relatively modest population sensitivity.
History supports the rating: Marshall County has received 20 federal disaster declarations since 1976, including 8 for flood events and 8 for severe storm events. The most recent was Flooding (flood), declared in July 2023.
Among 66 South Dakota counties, Marshall County ranks #40 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Winter Weather | Medium | 22.58 / yr | $216K |
| Wildfire | Low | 0.00 / yr | $309K |
| Hail | Low | 3.87 / yr | $624K |
| Cold Wave | Medium | 14.26 / yr | $2M |
| Ice Storm | Low | 0.35 / yr | $108K |
| Landslide | Very Low | 0.15 / yr | $1K |
| Strong Wind | Low | 2.76 / yr | $509K |
| Tornado | Low | 0.49 / yr | $591K |
| Heat Wave | Very Low | 2.53 / yr | $44K |
| Riverine Flood | Very Low | 0.93 / yr | $1M |
| Earthquake | Very Low | 0.00 / yr | $8K |
| Lightning | Very Low | 31.69 / yr | $8K |
| Avalanche | Very Low | 0.00 / yr | $0 |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Drought | Very Low | 0.00 / yr | $0 |
| Hurricane | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
| Volcanic Activity | Very Low | 0.00 / yr | $0 |
Disaster History
Marshall County has received 20 federal disaster declarations since 1976, most recently Flooding in July 2023. Most frequent causes: Flood (8), Severe Storm (8), Biological (2).
| Declared | Type | Disaster |
|---|---|---|
| July 2023 | Flood | Flooding |
| April 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| June 2019 | Flood | Severe Winter Storm, Snowstorm, and Flooding |
| February 2017 | Severe Storm | Severe Winter Storm |
| May 2011 | Flood | Flooding |
| May 2010 | Flood | Flooding |
| June 2009 | Severe Storm | Severe Storms and Flooding |
| May 2007 | Severe Storm | Severe Storms, Tornadoes, and Flooding |
| December 2005 | Severe Storm | Severe Winter Storm |
Showing the 10 most recent of 20 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Marshall County?
Marshall County has a composite FEMA National Risk Index score of 14.5 out of 100, placing it in the Very Low category and the 14th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Marshall County?
The three highest-rated hazards are Winter Weather (Medium, $216K EAL), Wildfire (Low, $309K EAL), Hail (Low, $624K EAL). These account for most of the county's expected annual losses.
How does Marshall County compare to other South Dakota counties?
Marshall County ranks #40 of 66 South Dakota counties for overall natural disaster risk, with a very low rating.
How many federally declared disasters has Marshall County had?
FEMA records 20 federal disaster declarations for Marshall County since 1976, most often 8 for flood events and 8 for severe storm events. The most recent was Flooding, declared in July 2023.
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. Marshall County's $6M EAL is a statistical average, not a guarantee for any specific year or address.