Harrison County
Iowa — Natural Disaster Risk Assessment
Very LowComposite Risk Score
National percentile: 31th
Harrison County faces very low composite natural disaster risk (NRI Risk Index score 31.3, 31th national percentile), driven primarily by drought and hail exposure. Expected annual loss across all 18 hazard types is $10M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Top Hazards
All 18 Hazard Risks
| Drought | Medium | 19.03 / yr | $1M |
| Hail | Medium | 6.39 / yr | $1M |
| Landslide | Low | 0.44 / yr | $27K |
| Tornado | Low | 0.56 / yr | $2M |
| Wildfire | Very Low | 0.00 / yr | $80K |
| Strong Wind | Medium | 4.50 / yr | $627K |
| Ice Storm | Low | 0.89 / yr | $96K |
| Riverine Flood | Low | 0.89 / yr | $4M |
| Winter Weather | Low | 14.26 / yr | $37K |
| Cold Wave | Low | 5.63 / yr | $379K |
| Heat Wave | Very Low | 6.42 / yr | $56K |
| Lightning | Very Low | 44.16 / yr | $55K |
| Earthquake | Very Low | 0.00 / yr | $12K |
| 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 Harrison County?
Harrison County has a composite FEMA National Risk Index score of 31.3 out of 100, placing it in the Very Low category and the 31th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Harrison County?
The three highest-rated hazards are Drought (Medium, $1M EAL), Hail (Medium, $1M EAL), Landslide (Low, $27K EAL). These account for most of the county's expected annual losses.
How does Harrison County compare to other Iowa counties?
Harrison County ranks #61 of 99 Iowa 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. Harrison County's $10M EAL is a statistical average, not a guarantee for any specific year or address.