McHenry County Disaster Risk
McHenry County, Illinois
FEMA Risk Rating
Relatively Moderate
National Percentile
91th
of 3,144 counties
State Rank
#10
of 102 (1 = highest risk)
Flood Risk
93th
percentile
Hazard Risk Breakdown
Flood
River, coastal, and surface flooding risk
Moderate
Higher than 93% of US counties
Wildfire
Wildland and wildland-urban interface fire risk
Very Low
Higher than 32% of US counties
Tornado
Tornado and severe thunderstorm risk
Relatively High
Higher than 96% of US counties
Earthquake
Seismic activity and ground shaking risk
Relatively Low
Higher than 75% of US counties
Hurricane
Tropical cyclone and hurricane risk
Very Low
Higher than 10% of US counties
Risk Overview
About Natural Disaster Risk in McHenry County, Illinois
McHenry faces above-average risk
McHenry County's composite risk score of 90.78 places it in the Relatively Moderate category, well above Illinois's state average of 54.46. This elevated profile makes McHenry one of the state's higher-risk counties overall.
Among Illinois's riskiest counties
McHenry County ranks as one of the highest-risk counties in Illinois, with exceptionally high tornado (96.34) and flood (93.10) risks. Its wildfire risk of 31.62 is notably elevated compared to most Illinois counties.
Riskier than most surrounding areas
McHenry County's composite score of 90.78 is comparable to Madison County (93.42) and McLean County (86.90), placing it among the state's most vulnerable regions. It significantly exceeds the risk profiles of most other northern Illinois counties.
Flooding and tornadoes are paramount
McHenry County faces a flood risk of 93.10 and tornado risk of 96.34—both extraordinarily high and among the state's worst. These dual threats make comprehensive preparedness and proper insurance coverage essential for all residents.
Flood and wind coverage are critical
McHenry County's extreme flood (93.10) and tornado (96.34) risks mean flood insurance and wind damage coverage are not optional. Consider reinforcing your home's structural integrity and maintaining a well-supplied emergency shelter space.
Source: FEMA National Risk Index · Narrative reviewed by Evan Brooks, Data Editor
Preparedness Guide
What to Prepare for in McHenry County
Top Hazards by Exposure
Source: FEMA National Risk Index v1.19.0 · Percentiles are national (3,144 counties)
Risk Advisory: McHenry County
Risk Verdict
FEMA's National Risk Index rates McHenry County at the 91th percentile nationally — above average and worth proactive preparation. Residents should prioritize a formal household emergency plan, including evacuation routes, insurance review, and a well-stocked emergency kit.
Hazard Breakdown
Tornado risk is McHenry County's dominant natural hazard, ranked at the 96th percentile nationally under FEMA's National Risk Index. Flood ranks second at the 93th percentile nationally. Additional tracked hazards include earthquake (75th percentile), wildfire (32th percentile), hurricane (10th percentile).
Preparedness Context
With tornado ranked at the 96th percentile nationally, McHenry County sits in a high-exposure zone where the difference between outcomes often comes down to proximity to a reinforced interior shelter and seconds of warning time. Flood is the second hazard driver for McHenry County at the 93th percentile nationally, meaning households should maintain awareness of both severe-weather and flood-specific warning systems. For McHenry County households, safe rooms certified to FEMA 320/361 standards offer the highest protection during a direct tornado hit; households without a safe room should locate the innermost lowest-floor room in their building and practice the route to it before storm season.
Regional Context
McHenry County is 36.3 composite risk points above the Illinois average, indicating that residents face greater natural hazard exposure than most of their in-state neighbors.
Is your household prepared for McHenry County's hazards?
Review FEMA's county-specific preparedness checklists and emergency planning guides.
Frequently Asked Questions
What is the natural disaster risk in McHenry County, IL?
What types of natural hazards affect McHenry County?
How does McHenry County risk compare to the Illinois average?
Is McHenry County at risk for tornado?
How is natural disaster risk measured?
Why is McHenry County higher risk than average?
Data Source
Risk data sourced from the FEMA National Risk Index (NRI). Risk scores are relative rankings (0–100) across all US counties — not absolute risk measures. Higher scores indicate higher relative risk compared to other counties.
Disclaimer: This data is informational only. It is not financial, insurance, or legal advice. Always consult a qualified professional before making insurance or real estate decisions.