Knox County, Illinois Natural Disaster Risk
FEMA National Risk Index assessment · IL
LowComposite Risk Score
National percentile: 57th
Knox County faces low composite natural disaster risk (NRI Risk Index score 57.2, 57th national percentile), driven primarily by strong wind and hail exposure. Expected annual loss across all 18 hazard types is $18M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
FEMA's National Risk Index rates Knox County at low composite risk, with a National Risk Index score of 57.2 out of 100 — placing it in the 57th national percentile and below the national average for natural-disaster risk. The score blends Expected Annual Loss, Social Vulnerability, and Community Resilience across all 18 FEMA hazard types.
Risk here concentrates in strong wind (damaging straight-line winds outside of tornadoes and hurricanes) at High risk — $3M in expected annual loss and about 5.87 events per year; hail (ice stones from severe thunderstorms that damage property and crops) at Medium risk — $1M in expected annual loss and about 3.95 events per year; and heat wave (prolonged periods of extreme heat that threaten health and infrastructure) at Medium risk — $1M in expected annual loss and about 6.42 events per year. Across all hazards, FEMA estimates $18M in expected annual loss for a population of 50K.
Beyond physical exposure, Knox County has a medium social vulnerability rating (how susceptible the population is to harm) and a high community resilience rating (its capacity to prepare for and recover from disasters). A less vulnerable population paired with strong resilience helps the community absorb and recover from events.
The county's disaster history tells the same story: Knox County has received 11 federal disaster declarations since 1974, including 4 for flood events and 3 for snowstorm events. The most recent was Covid-19 Pandemic (biological), declared in March 2020.
Among 102 Illinois counties, Knox County ranks #48 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Strong Wind | High | 5.87 / yr | $3M |
| Hail | Medium | 3.95 / yr | $1M |
| Heat Wave | Medium | 6.42 / yr | $1M |
| Cold Wave | Medium | 5.58 / yr | $3M |
| Drought | Medium | 8.88 / yr | $623K |
| Ice Storm | Medium | 0.91 / yr | $215K |
| Landslide | Low | 0.27 / yr | $6K |
| Tornado | Medium | 0.68 / yr | $2M |
| Lightning | Medium | 45.43 / yr | $401K |
| Earthquake | Very Low | 0.00 / yr | $388K |
| Winter Weather | Low | 11.11 / yr | $74K |
| Riverine Flood | Low | 1.36 / yr | $6M |
| Hurricane | Very Low | 0.01 / yr | $7K |
| Wildfire | Very Low | 0.00 / yr | $446 |
| 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 |
Disaster History
Knox County has received 11 federal disaster declarations since 1974, most recently Covid-19 Pandemic in March 2020. Most frequent causes: Flood (4), Snowstorm (3), Biological (2).
| Declared | Type | Disaster |
|---|---|---|
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| September 2019 | Flood | Severe Storms and Flooding |
| May 2013 | Flood | Severe Storms, Straight-Line Winds, and Flooding |
| March 2011 | Snowstorm | Severe Winter Storm and Snowstorm |
| September 2007 | Severe Storm | Severe Storms and Flooding |
| December 2006 | Snowstorm | Snow |
| September 2005 | Hurricane | Hurricane Katrina Evacuation |
| January 1999 | Snowstorm | Il-Winter Storm 1/1/99 |
| July 1993 | Flood | Severe Storms & Flooding |
Showing the 10 most recent of 11 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Knox County?
Knox County has a composite FEMA National Risk Index score of 57.2 out of 100, placing it in the Low category and the 57th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Knox County?
The three highest-rated hazards are Strong Wind (High, $3M EAL), Hail (Medium, $1M EAL), Heat Wave (Medium, $1M EAL). These account for most of the county's expected annual losses.
How does Knox County compare to other Illinois counties?
Knox County ranks #48 of 102 Illinois counties for overall natural disaster risk, with a low rating.
How many federally declared disasters has Knox County had?
FEMA records 11 federal disaster declarations for Knox County since 1974, most often 4 for flood events and 3 for snowstorm events. The most recent was Covid-19 Pandemic, declared in March 2020.
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. Knox County's $18M EAL is a statistical average, not a guarantee for any specific year or address.