Minnehaha County
South Dakota — Natural Disaster Risk Assessment
MediumComposite Risk Score
National percentile: 90th
Minnehaha County faces medium composite natural disaster risk (NRI Risk Index score 89.5, 90th national percentile), driven primarily by ice storm and tornado exposure. Expected annual loss across all 18 hazard types is $104M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Top Hazards
All 18 Hazard Risks
| Ice Storm | Very High | 1.11 / yr | $5M |
| Tornado | High | 0.67 / yr | $36M |
| Winter Weather | High | 17.63 / yr | $1M |
| Cold Wave | High | 8.53 / yr | $17M |
| Hail | Medium | 5.93 / yr | $3M |
| Strong Wind | High | 3.96 / yr | $3M |
| Heat Wave | Medium | 5.58 / yr | $3M |
| Riverine Flood | Medium | 4.50 / yr | $34M |
| Drought | Medium | 15.19 / yr | $807K |
| Wildfire | Low | 0.00 / yr | $243K |
| Lightning | Low | 37.73 / yr | $359K |
| Landslide | Very Low | 0.11 / yr | $2K |
| Earthquake | Very Low | 0.00 / yr | $162K |
| 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 |
Frequently Asked Questions
What is the overall natural disaster risk for Minnehaha County?
Minnehaha County has a composite FEMA National Risk Index score of 89.5 out of 100, placing it in the Medium category and the 90th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Minnehaha County?
The three highest-rated hazards are Ice Storm (Very High, $5M EAL), Tornado (High, $36M EAL), Winter Weather (High, $1M EAL). These account for most of the county's expected annual losses.
How does Minnehaha County compare to other South Dakota counties?
Minnehaha County ranks #1 of 66 South Dakota counties for overall natural disaster risk, with a medium 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. Minnehaha County's $104M EAL is a statistical average, not a guarantee for any specific year or address.