Jefferson County, Illinois Natural Disaster Risk
FEMA National Risk Index assessment · IL
LowComposite Risk Score
National percentile: 77th
Jefferson County faces low composite natural disaster risk (NRI Risk Index score 77.2, 77th national percentile), driven primarily by earthquake and strong wind exposure. Expected annual loss across all 18 hazard types is $34M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Overall natural disaster risk in Jefferson County is low, with a National Risk Index score of 77.2 out of 100 — placing it in the 77th 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 earthquake (ground shaking from sudden movement along geologic faults) at Medium risk — $16M in expected annual loss and about 0.01 events per year; strong wind (damaging straight-line winds outside of tornadoes and hurricanes) at High risk — $2M in expected annual loss and about 4.40 events per year; and winter weather (heavy snow, blizzards, and hazardous winter conditions) at High risk — $284K in expected annual loss and about 8.26 events per year. Across all hazards, FEMA estimates $34M in expected annual loss for a population of 37K.
Beyond physical exposure, Jefferson 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.
History supports the rating: Jefferson County has received 5 federal disaster declarations since 2002, including 2 for biological events and 1 for severe storm events. The most recent was Covid-19 Pandemic (biological), declared in March 2020.
Among 102 Illinois counties, Jefferson County ranks #27 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Earthquake | Medium | 0.01 / yr | $16M |
| Strong Wind | High | 4.40 / yr | $2M |
| Winter Weather | High | 8.26 / yr | $284K |
| Heat Wave | Medium | 9.89 / yr | $1M |
| Tornado | Medium | 0.45 / yr | $3M |
| Hail | Medium | 3.37 / yr | $648K |
| Landslide | Low | 0.42 / yr | $6K |
| Cold Wave | Low | 1.21 / yr | $1M |
| Riverine Flood | Low | 1.54 / yr | $8M |
| Drought | Low | 1.66 / yr | $231K |
| Lightning | Low | 51.62 / yr | $186K |
| Ice Storm | Low | 0.48 / yr | $58K |
| Hurricane | Very Low | 0.02 / yr | $26K |
| 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 |
Disaster History
Jefferson County has received 5 federal disaster declarations since 2002, most recently Covid-19 Pandemic in March 2020. Most frequent causes: Biological (2), Severe Storm (1), Hurricane (1).
| Declared | Type | Disaster |
|---|---|---|
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| June 2011 | Severe Storm | Severe Storms and Flooding |
| September 2005 | Hurricane | Hurricane Katrina Evacuation |
| May 2002 | Tornado | Severe Storms, Tornadoes and Flooding |
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Jefferson County?
Jefferson County has a composite FEMA National Risk Index score of 77.2 out of 100, placing it in the Low category and the 77th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Jefferson County?
The three highest-rated hazards are Earthquake (Medium, $16M EAL), Strong Wind (High, $2M EAL), Winter Weather (High, $284K EAL). These account for most of the county's expected annual losses.
How does Jefferson County compare to other Illinois counties?
Jefferson County ranks #27 of 102 Illinois counties for overall natural disaster risk, with a low rating.
How many federally declared disasters has Jefferson County had?
FEMA records 5 federal disaster declarations for Jefferson County since 2002, most often 2 for biological events and 1 for severe storm 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. Jefferson County's $34M EAL is a statistical average, not a guarantee for any specific year or address.