Hamilton County, Illinois Natural Disaster Risk
FEMA National Risk Index assessment · IL
Very LowComposite Risk Score
National percentile: 31th
Hamilton County faces very low composite natural disaster risk (NRI Risk Index score 30.8, 31th national percentile), driven primarily by earthquake and strong wind exposure. Expected annual loss across all 18 hazard types is $12M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
FEMA's National Risk Index rates Hamilton County at very low composite risk, with a National Risk Index score of 30.8 out of 100 — placing it in the 31st national percentile and among the lowest-risk counties in the country. The score blends Expected Annual Loss, Social Vulnerability, and Community Resilience across all 18 FEMA hazard types.
The county's risk is driven primarily by earthquake (ground shaking from sudden movement along geologic faults) at Medium risk — $7M in expected annual loss and about 0.01 events per year; strong wind (damaging straight-line winds outside of tornadoes and hurricanes) at Medium risk — $803K in expected annual loss and about 3.99 events per year; and winter weather (heavy snow, blizzards, and hazardous winter conditions) at Low risk — $88K in expected annual loss and about 7.89 events per year. Across all hazards, FEMA estimates $12M in expected annual loss for a population of 8K.
Beyond physical exposure, Hamilton County has a very low 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 federal record bears this out: Hamilton County has received 10 federal disaster declarations since 1989, including 4 for severe storm events and 2 for biological events. The most recent was Covid-19 Pandemic (biological), declared in March 2020.
Among 102 Illinois counties, Hamilton County ranks #79 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Earthquake | Medium | 0.01 / yr | $7M |
| Strong Wind | Medium | 3.99 / yr | $803K |
| Winter Weather | Low | 7.89 / yr | $88K |
| Drought | Low | 3.18 / yr | $218K |
| Landslide | Very Low | 0.26 / yr | $2K |
| Heat Wave | Low | 9.32 / yr | $345K |
| Tornado | Low | 0.32 / yr | $939K |
| Ice Storm | Low | 0.54 / yr | $55K |
| Hail | Low | 3.06 / yr | $180K |
| Cold Wave | Low | 1.16 / yr | $545K |
| Hurricane | Very Low | 0.01 / yr | $15K |
| Riverine Flood | Very Low | 1.39 / yr | $2M |
| Lightning | Very Low | 52.75 / yr | $52K |
| Wildfire | Very Low | 0.00 / yr | $598 |
| 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
Hamilton County has received 10 federal disaster declarations since 1989, most recently Covid-19 Pandemic in March 2020. Most frequent causes: Severe Storm (4), Biological (2), Tornado (2).
| Declared | Type | Disaster |
|---|---|---|
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| June 2011 | Severe Storm | Severe Storms and Flooding |
| July 2009 | Severe Storm | Severe Storms, Flooding, and Tornadoes |
| September 2005 | Hurricane | Hurricane Katrina Evacuation |
| February 2005 | Snowstorm | Record/Near Record Snow |
| May 2002 | Tornado | Severe Storms, Tornadoes and Flooding |
| May 1996 | Severe Storm | Severe Storms and Flooding |
| June 1990 | Severe Storm | Severe Storms, Tornadoes & Flooding |
| January 1989 | Tornado | Severe Storms & Tornadoes |
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Hamilton County?
Hamilton County has a composite FEMA National Risk Index score of 30.8 out of 100, placing it in the Very Low category and the 31th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Hamilton County?
The three highest-rated hazards are Earthquake (Medium, $7M EAL), Strong Wind (Medium, $803K EAL), Winter Weather (Low, $88K EAL). These account for most of the county's expected annual losses.
How does Hamilton County compare to other Illinois counties?
Hamilton County ranks #79 of 102 Illinois counties for overall natural disaster risk, with a very low rating.
How many federally declared disasters has Hamilton County had?
FEMA records 10 federal disaster declarations for Hamilton County since 1989, most often 4 for severe storm events and 2 for biological 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. Hamilton County's $12M EAL is a statistical average, not a guarantee for any specific year or address.