Warren County, Illinois Natural Disaster Risk
FEMA National Risk Index assessment · IL
Very LowComposite Risk Score
National percentile: 15th
Warren County faces very low composite natural disaster risk (NRI Risk Index score 15.5, 15th national percentile), driven primarily by drought and heat wave exposure. Expected annual loss across all 18 hazard types is $7M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Warren County carries a very low composite natural disaster risk, with a National Risk Index score of 15.5 out of 100 — placing it in the 15th 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.
Most of Warren County's expected losses come from drought (extended dry periods that stress water supplies and agriculture) at Medium risk — $1M in expected annual loss and about 8.87 events per year; heat wave (prolonged periods of extreme heat that threaten health and infrastructure) at Low risk — $864K in expected annual loss and about 8.84 events per year; and hail (ice stones from severe thunderstorms that damage property and crops) at Low risk — $526K in expected annual loss and about 3.97 events per year. Across all hazards, FEMA estimates $7M in expected annual loss for a population of 17K.
Beyond physical exposure, Warren County has a low social vulnerability rating (how susceptible the population is to harm) and a very 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: Warren County has received 9 federal disaster declarations since 1993, including 2 for severe storm events and 2 for biological events. The most recent was Severe Storms and Flooding (severe storm), declared in August 2023.
Among 102 Illinois counties, Warren County ranks #92 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Drought | Medium | 8.87 / yr | $1M |
| Heat Wave | Low | 8.84 / yr | $864K |
| Hail | Low | 3.97 / yr | $526K |
| Ice Storm | Low | 0.84 / yr | $123K |
| Cold Wave | Low | 4.63 / yr | $1M |
| Landslide | Very Low | 0.14 / yr | $2K |
| Strong Wind | Low | 5.79 / yr | $564K |
| Lightning | Low | 45.57 / yr | $164K |
| Earthquake | Very Low | 0.00 / yr | $122K |
| Winter Weather | Low | 12.84 / yr | $39K |
| Tornado | Low | 0.49 / yr | $529K |
| Hurricane | Very Low | 0.01 / yr | $6K |
| Riverine Flood | Very Low | 0.79 / yr | $2M |
| Wildfire | Very Low | 0.00 / yr | $91 |
| 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
Warren County has received 9 federal disaster declarations since 1993, most recently Severe Storms and Flooding in August 2023. Most frequent causes: Severe Storm (2), Biological (2), Flood (2).
| Declared | Type | Disaster |
|---|---|---|
| August 2023 | Severe Storm | Severe Storms and Flooding |
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| 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 |
| September 2005 | Hurricane | Hurricane Katrina Evacuation |
| January 1999 | Snowstorm | Il-Winter Storm 1/1/99 |
| July 1993 | Flood | Severe Storms & Flooding |
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Warren County?
Warren County has a composite FEMA National Risk Index score of 15.5 out of 100, placing it in the Very Low category and the 15th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Warren County?
The three highest-rated hazards are Drought (Medium, $1M EAL), Heat Wave (Low, $864K EAL), Hail (Low, $526K EAL). These account for most of the county's expected annual losses.
How does Warren County compare to other Illinois counties?
Warren County ranks #92 of 102 Illinois counties for overall natural disaster risk, with a very low rating.
How many federally declared disasters has Warren County had?
FEMA records 9 federal disaster declarations for Warren County since 1993, most often 2 for severe storm events and 2 for biological events. The most recent was Severe Storms and Flooding, declared in August 2023.
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. Warren County's $7M EAL is a statistical average, not a guarantee for any specific year or address.