Custer County
South Dakota — Natural Disaster Risk Assessment
Very LowComposite Risk Score
National percentile: 16th
Custer County faces very low composite natural disaster risk (NRI Risk Index score 16.3, 16th national percentile), driven primarily by wildfire and winter weather exposure. Expected annual loss across all 18 hazard types is $9M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Top Hazards
All 18 Hazard Risks
| Wildfire | Medium | 0.01 / yr | $4M |
| Winter Weather | Low | 15.06 / yr | $127K |
| Landslide | Very Low | 0.59 / yr | $2K |
| Hail | Low | 6.21 / yr | $292K |
| Earthquake | Very Low | 0.00 / yr | $63K |
| Lightning | Low | 45.32 / yr | $123K |
| Cold Wave | Very Low | 3.98 / yr | $399K |
| Tornado | Very Low | 0.37 / yr | $396K |
| Riverine Flood | Very Low | 1.18 / yr | $3M |
| Drought | Very Low | 62.71 / yr | $2K |
| Strong Wind | Very Low | 2.52 / yr | $185K |
| Heat Wave | Very Low | 0.38 / yr | $8K |
| Ice Storm | Very Low | 0.01 / yr | $2K |
| Avalanche | Very Low | 0.01 / yr | $1 |
| 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 |
Frequently Asked Questions
What is the overall natural disaster risk for Custer County?
Custer County has a composite FEMA National Risk Index score of 16.3 out of 100, placing it in the Very Low category and the 16th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Custer County?
The three highest-rated hazards are Wildfire (Medium, $4M EAL), Winter Weather (Low, $127K EAL), Landslide (Very Low, $2K EAL). These account for most of the county's expected annual losses.
How does Custer County compare to other South Dakota counties?
Custer County ranks #37 of 66 South Dakota counties for overall natural disaster risk, with a very low rating.
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. Custer County's $9M EAL is a statistical average, not a guarantee for any specific year or address.