Decatur County
Iowa — Natural Disaster Risk Assessment
Very LowComposite Risk Score
National percentile: 24th
Decatur County faces very low composite natural disaster risk (NRI Risk Index score 23.6, 24th national percentile), driven primarily by drought and landslide exposure. Expected annual loss across all 18 hazard types is $8M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Top Hazards
All 18 Hazard Risks
| Drought | High | 12.39 / yr | $2M |
| Landslide | Low | 0.39 / yr | $7K |
| Heat Wave | Low | 7.74 / yr | $660K |
| Cold Wave | Low | 4.42 / yr | $1M |
| Wildfire | Very Low | 0.00 / yr | $51K |
| Tornado | Low | 0.38 / yr | $1M |
| Hail | Low | 5.38 / yr | $229K |
| Strong Wind | Low | 4.61 / yr | $413K |
| Ice Storm | Very Low | 0.39 / yr | $20K |
| Earthquake | Very Low | 0.00 / yr | $24K |
| Lightning | Very Low | 45.63 / yr | $55K |
| Winter Weather | Very Low | 11.53 / yr | $13K |
| Riverine Flood | Very Low | 1.82 / yr | $2M |
| Hurricane | Very Low | 0.01 / yr | $1K |
| 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 Decatur County?
Decatur County has a composite FEMA National Risk Index score of 23.6 out of 100, placing it in the Very Low category and the 24th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Decatur County?
The three highest-rated hazards are Drought (High, $2M EAL), Landslide (Low, $7K EAL), Heat Wave (Low, $660K EAL). These account for most of the county's expected annual losses.
How does Decatur County compare to other Iowa counties?
Decatur County ranks #79 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. Decatur County's $8M EAL is a statistical average, not a guarantee for any specific year or address.