Butte County, South Dakota Natural Disaster Risk
FEMA National Risk Index assessment · SD
Very LowComposite Risk Score
National percentile: 23th
Butte County faces very low composite natural disaster risk (NRI Risk Index score 23.3, 23th national percentile), driven primarily by wildfire and hail exposure. Expected annual loss across all 18 hazard types is $8M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Overall natural disaster risk in Butte County is very low, with a National Risk Index score of 23.3 out of 100 — placing it in the 23rd 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 wildfire (uncontrolled fires that spread across wildland and into communities) at Low risk — $865K in expected annual loss and about 0.00 events per year; hail (ice stones from severe thunderstorms that damage property and crops) at Medium risk — $686K in expected annual loss and about 4.62 events per year; and winter weather (heavy snow, blizzards, and hazardous winter conditions) at Medium risk — $125K in expected annual loss and about 16.48 events per year. Across all hazards, FEMA estimates $8M in expected annual loss for a population of 10K.
Beyond physical exposure, Butte County has a low 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). Both measures sit toward the lower end, indicating relatively modest population sensitivity.
History supports the rating: Butte County has received 21 federal disaster declarations since 1965, including 9 for severe storm events and 7 for flood events. The most recent was Severe Storm, Straight-Line Winds, Tornadoes, and Flooding (severe storm), declared in August 2022.
Among 66 South Dakota counties, Butte County ranks #31 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Wildfire | Low | 0.00 / yr | $865K |
| Hail | Medium | 4.62 / yr | $686K |
| Winter Weather | Medium | 16.48 / yr | $125K |
| Cold Wave | Low | 6.74 / yr | $1M |
| Strong Wind | Low | 2.45 / yr | $522K |
| Riverine Flood | Very Low | 0.71 / yr | $4M |
| Landslide | Very Low | 0.48 / yr | $391 |
| Lightning | Low | 36.46 / yr | $106K |
| Earthquake | Very Low | 0.00 / yr | $63K |
| Tornado | Very Low | 0.38 / yr | $318K |
| Ice Storm | Very Low | 0.18 / yr | $18K |
| Drought | Very Low | 48.76 / yr | $4K |
| Heat Wave | Very Low | 0.68 / yr | $30K |
| 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
Butte County has received 21 federal disaster declarations since 1965, most recently Severe Storm, Straight-Line Winds, Tornadoes, and Flooding in August 2022. Most frequent causes: Severe Storm (9), Flood (7), Biological (2).
| Declared | Type | Disaster |
|---|---|---|
| August 2022 | Severe Storm | Severe Storm, Straight-Line Winds, Tornadoes, and Flooding |
| April 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| October 2019 | Severe Storm | Severe Storms, Tornadoes, and Flooding |
| September 2019 | Flood | Severe Storms and Flooding |
| February 2017 | Severe Storm | Severe Winter Storm |
| July 2014 | Flood | Severe Storms, Tornadoes, and Flooding |
| November 2013 | Severe Storm | Severe Winter Storm, Snowstorm, and Flooding |
| May 2011 | Flood | Flooding |
| June 2009 | Severe Storm | Severe Storms and Flooding |
Showing the 10 most recent of 21 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Butte County?
Butte County has a composite FEMA National Risk Index score of 23.3 out of 100, placing it in the Very Low category and the 23th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Butte County?
The three highest-rated hazards are Wildfire (Low, $865K EAL), Hail (Medium, $686K EAL), Winter Weather (Medium, $125K EAL). These account for most of the county's expected annual losses.
How does Butte County compare to other South Dakota counties?
Butte County ranks #31 of 66 South Dakota counties for overall natural disaster risk, with a very low rating.
How many federally declared disasters has Butte County had?
FEMA records 21 federal disaster declarations for Butte County since 1965, most often 9 for severe storm events and 7 for flood events. The most recent was Severe Storm, Straight-Line Winds, Tornadoes, and Flooding, declared in August 2022.
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. Butte County's $8M EAL is a statistical average, not a guarantee for any specific year or address.