Buffalo County, South Dakota Natural Disaster Risk
FEMA National Risk Index assessment · SD
Very LowComposite Risk Score
National percentile: 14th
Buffalo County faces very low composite natural disaster risk (NRI Risk Index score 13.7, 14th national percentile), driven primarily by cold wave and wildfire exposure. Expected annual loss across all 18 hazard types is $4M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Buffalo County carries a very low composite natural disaster risk, with a National Risk Index score of 13.7 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 cold wave (prolonged spells of dangerously low temperatures) at Medium risk — $2M in expected annual loss and about 7.16 events per year; wildfire (uncontrolled fires that spread across wildland and into communities) at Low risk — $221K in expected annual loss and about 0.00 events per year; and winter weather (heavy snow, blizzards, and hazardous winter conditions) at Low risk — $49K in expected annual loss and about 16.63 events per year. Across all hazards, FEMA estimates $4M in expected annual loss for a population of 2K.
Beyond physical exposure, Buffalo 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.
History supports the rating: Buffalo County has received 20 federal disaster declarations since 1969, including 8 for flood events and 6 for severe storm events. The most recent was Severe Storms, Straight-Line Winds, and Flooding (flood), declared in August 2024.
Among 66 South Dakota counties, Buffalo County ranks #41 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Cold Wave | Medium | 7.16 / yr | $2M |
| Wildfire | Low | 0.00 / yr | $221K |
| Winter Weather | Low | 16.63 / yr | $49K |
| Drought | Low | 14.41 / yr | $54K |
| Ice Storm | Low | 0.38 / yr | $27K |
| Strong Wind | Low | 2.76 / yr | $220K |
| Hail | Very Low | 4.01 / yr | $72K |
| Tornado | Very Low | 0.19 / yr | $179K |
| Heat Wave | Very Low | 4.79 / yr | $27K |
| Earthquake | Very Low | 0.00 / yr | $10K |
| Riverine Flood | Very Low | 0.57 / yr | $1M |
| Landslide | Very Low | 0.10 / yr | $7 |
| Lightning | Very Low | 35.77 / yr | $10K |
| Avalanche | Very Low | 0.00 / yr | $0 |
| Coastal Flood | 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
Buffalo County has received 20 federal disaster declarations since 1969, most recently Severe Storms, Straight-Line Winds, and Flooding in August 2024. Most frequent causes: Flood (8), Severe Storm (6), Biological (2).
| Declared | Type | Disaster |
|---|---|---|
| August 2024 | Flood | Severe Storms, Straight-Line Winds, and Flooding |
| April 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| June 2019 | Flood | Severe Winter Storm, Snowstorm, and Flooding |
| July 2015 | Severe Storm | Severe Storms, Tornadoes, Straight-Line Winds, and Flooding |
| May 2011 | Flood | Flooding |
| May 2010 | Flood | Flooding |
| March 2010 | Severe Storm | Severe Winter Storm |
| July 2008 | Severe Storm | Severe Storms and Flooding |
| May 2007 | Severe Storm | Severe Storms, Tornadoes, and Flooding |
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 Buffalo County?
Buffalo County has a composite FEMA National Risk Index score of 13.7 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 Buffalo County?
The three highest-rated hazards are Cold Wave (Medium, $2M EAL), Wildfire (Low, $221K EAL), Winter Weather (Low, $49K EAL). These account for most of the county's expected annual losses.
How does Buffalo County compare to other South Dakota counties?
Buffalo County ranks #41 of 66 South Dakota counties for overall natural disaster risk, with a very low rating.
How many federally declared disasters has Buffalo County had?
FEMA records 20 federal disaster declarations for Buffalo County since 1969, most often 8 for flood events and 6 for severe storm events. The most recent was Severe Storms, Straight-Line Winds, and Flooding, declared in August 2024.
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. Buffalo County's $4M EAL is a statistical average, not a guarantee for any specific year or address.