Mercer County
Illinois — Natural Disaster Risk Assessment
Very LowComposite Risk Score
National percentile: 9th
Mercer County faces very low composite natural disaster risk (NRI Risk Index score 8.8, 9th national percentile), driven primarily by drought and landslide exposure. Expected annual loss across all 18 hazard types is $7M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Top Hazards
All 18 Hazard Risks
| Drought | Medium | 8.21 / yr | $907K |
| Landslide | Low | 0.24 / yr | $8K |
| Ice Storm | Medium | 0.67 / yr | $285K |
| Strong Wind | Medium | 6.25 / yr | $1M |
| Lightning | Medium | 44.82 / yr | $492K |
| Heat Wave | Low | 8.16 / yr | $551K |
| Cold Wave | Low | 5.37 / yr | $777K |
| Hail | Very Low | 4.23 / yr | $182K |
| Winter Weather | Low | 14.16 / yr | $40K |
| Earthquake | Very Low | 0.00 / yr | $69K |
| Tornado | Very Low | 0.53 / yr | $467K |
| Hurricane | Very Low | 0.01 / yr | $4K |
| Riverine Flood | Very Low | 1.64 / yr | $2M |
| Wildfire | Very Low | 0.00 / yr | $719 |
| 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 Mercer County?
Mercer County has a composite FEMA National Risk Index score of 8.8 out of 100, placing it in the Very Low category and the 9th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Mercer County?
The three highest-rated hazards are Drought (Medium, $907K EAL), Landslide (Low, $8K EAL), Ice Storm (Medium, $285K EAL). These account for most of the county's expected annual losses.
How does Mercer County compare to other Illinois counties?
Mercer County ranks #97 of 102 Illinois 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. Mercer County's $7M EAL is a statistical average, not a guarantee for any specific year or address.