McHenry County
Illinois — Natural Disaster Risk Assessment
MediumComposite Risk Score
National percentile: 91th
McHenry County faces medium composite natural disaster risk (NRI Risk Index score 90.8, 91th national percentile), driven primarily by cold wave and tornado exposure. Expected annual loss across all 18 hazard types is $142M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Top Hazards
All 18 Hazard Risks
| Cold Wave | High | 5.69 / yr | $23M |
| Tornado | High | 0.44 / yr | $25M |
| Riverine Flood | Medium | 1.11 / yr | $85M |
| Strong Wind | High | 6.27 / yr | $3M |
| Hail | Medium | 4.84 / yr | $1M |
| Winter Weather | Medium | 14.59 / yr | $310K |
| Heat Wave | Low | 2.79 / yr | $2M |
| Earthquake | Low | 0.00 / yr | $2M |
| Lightning | Medium | 39.18 / yr | $871K |
| Drought | Low | 8.59 / yr | $420K |
| Landslide | Very Low | 0.11 / yr | $3K |
| Ice Storm | Low | 0.61 / yr | $171K |
| Wildfire | Very Low | 0.00 / yr | $25K |
| Hurricane | Very Low | 0.01 / 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 McHenry County?
McHenry County has a composite FEMA National Risk Index score of 90.8 out of 100, placing it in the Medium category and the 91th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in McHenry County?
The three highest-rated hazards are Cold Wave (High, $23M EAL), Tornado (High, $25M EAL), Riverine Flood (Medium, $85M EAL). These account for most of the county's expected annual losses.
How does McHenry County compare to other Illinois counties?
McHenry County ranks #10 of 102 Illinois counties for overall natural disaster risk, with a medium 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. McHenry County's $142M EAL is a statistical average, not a guarantee for any specific year or address.