Johnson County
Illinois — Natural Disaster Risk Assessment
LowComposite Risk Score
National percentile: 51th
Johnson County faces low composite natural disaster risk (NRI Risk Index score 51.1, 51th national percentile), driven primarily by earthquake and heat wave exposure. Expected annual loss across all 18 hazard types is $12M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Top Hazards
All 18 Hazard Risks
| Earthquake | Medium | 0.01 / yr | $4M |
| Heat Wave | Low | 10.47 / yr | $623K |
| Strong Wind | Medium | 4.04 / yr | $676K |
| Ice Storm | Medium | 0.91 / yr | $145K |
| Hail | Low | 3.20 / yr | $346K |
| Winter Weather | Medium | 7.47 / yr | $76K |
| Cold Wave | Low | 1.11 / yr | $1M |
| Tornado | Low | 0.30 / yr | $1M |
| Drought | Low | 4.02 / yr | $125K |
| Landslide | Very Low | 0.82 / yr | $636 |
| Hurricane | Very Low | 0.02 / yr | $19K |
| Riverine Flood | Low | 0.82 / yr | $3M |
| Lightning | Low | 55.10 / yr | $91K |
| Wildfire | Very Low | 0.00 / yr | $3K |
| 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 Johnson County?
Johnson County has a composite FEMA National Risk Index score of 51.1 out of 100, placing it in the Low category and the 51th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Johnson County?
The three highest-rated hazards are Earthquake (Medium, $4M EAL), Heat Wave (Low, $623K EAL), Strong Wind (Medium, $676K EAL). These account for most of the county's expected annual losses.
How does Johnson County compare to other Illinois counties?
Johnson County ranks #58 of 102 Illinois 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. Johnson County's $12M EAL is a statistical average, not a guarantee for any specific year or address.