Hamilton County
Iowa — Natural Disaster Risk Assessment
LowComposite Risk Score
National percentile: 43th
Hamilton County faces low composite natural disaster risk (NRI Risk Index score 42.9, 43th national percentile), driven primarily by drought and hail exposure. Expected annual loss across all 18 hazard types is $16M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Top Hazards
All 18 Hazard Risks
| Drought | High | 11.19 / yr | $4M |
| Hail | Low | 5.70 / yr | $712K |
| Strong Wind | Medium | 5.37 / yr | $1M |
| Winter Weather | Medium | 16.63 / yr | $129K |
| Tornado | Low | 0.58 / yr | $2M |
| Cold Wave | Low | 9.32 / yr | $2M |
| Riverine Flood | Low | 2.18 / yr | $6M |
| Ice Storm | Low | 0.65 / yr | $58K |
| Landslide | Very Low | 0.07 / yr | $467 |
| Hurricane | Very Low | 0.01 / yr | $6K |
| Lightning | Very Low | 42.39 / yr | $69K |
| Earthquake | Very Low | 0.00 / yr | $25K |
| Wildfire | Very Low | 0.00 / yr | $5K |
| Heat Wave | Very Low | 4.16 / yr | $23K |
| Avalanche | Very Low | 0.00 / yr | $0 |
| Coastal Flood | 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 Hamilton County?
Hamilton County has a composite FEMA National Risk Index score of 42.9 out of 100, placing it in the Low category and the 43th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Hamilton County?
The three highest-rated hazards are Drought (High, $4M EAL), Hail (Low, $712K EAL), Strong Wind (Medium, $1M EAL). These account for most of the county's expected annual losses.
How does Hamilton County compare to other Iowa counties?
Hamilton County ranks #35 of 99 Iowa counties for overall natural disaster risk, with a 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. Hamilton County's $16M EAL is a statistical average, not a guarantee for any specific year or address.