Will County, Illinois Natural Disaster Risk
FEMA National Risk Index assessment · IL
HighComposite Risk Score
National percentile: 97th
Will County faces high composite natural disaster risk (NRI Risk Index score 97.3, 97th national percentile), driven primarily by cold wave and tornado exposure. Expected annual loss across all 18 hazard types is $348M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
FEMA's National Risk Index rates Will County at high composite risk, with a National Risk Index score of 97.3 out of 100 — placing it in the 97th national percentile and in the upper tier of natural-disaster risk nationally. 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 cold wave (prolonged spells of dangerously low temperatures) at Very High risk — $72M in expected annual loss and about 4.30 events per year; tornado (violently rotating columns of air capable of catastrophic local damage) at Very High risk — $63M in expected annual loss and about 0.62 events per year; and riverine flood (rivers and streams overflowing their banks after heavy rain or snowmelt) at High risk — $193M in expected annual loss and about 3.00 events per year. Across all hazards, FEMA estimates $348M in expected annual loss for a population of 696K.
Beyond physical exposure, Will County has a very 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 federal record bears this out: Will County has received 19 federal disaster declarations since 1967, including 5 for severe storm events and 4 for flood events. The most recent was Severe Storms, Tornadoes, Straight-Line Winds, and Floodng (flood), declared in September 2024.
Among 102 Illinois counties, Will County ranks #3 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Cold Wave | Very High | 4.30 / yr | $72M |
| Tornado | Very High | 0.62 / yr | $63M |
| Riverine Flood | High | 3.00 / yr | $193M |
| Heat Wave | Medium | 3.64 / yr | $9M |
| Winter Weather | High | 14.37 / yr | $617K |
| Earthquake | Medium | 0.00 / yr | $7M |
| Lightning | High | 44.55 / yr | $2M |
| Ice Storm | Medium | 0.93 / yr | $532K |
| Hail | Low | 3.89 / yr | $498K |
| Landslide | Very Low | 0.17 / yr | $3K |
| Wildfire | Very Low | 0.00 / yr | $88K |
| Strong Wind | Low | 5.62 / yr | $730K |
| Drought | Low | 1.65 / yr | $72K |
| Hurricane | Very Low | 0.01 / yr | $14K |
| 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
Will County has received 19 federal disaster declarations since 1967, most recently Severe Storms, Tornadoes, Straight-Line Winds, and Floodng in September 2024. Most frequent causes: Severe Storm (5), Flood (4), Snowstorm (4).
| Declared | Type | Disaster |
|---|---|---|
| September 2024 | Flood | Severe Storms, Tornadoes, Straight-Line Winds, and Floodng |
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| November 2013 | Tornado | Severe Storms, Straight-Line Winds, and Tornadoes |
| May 2013 | Flood | Severe Storms, Straight-Line Winds, and Flooding |
| March 2011 | Snowstorm | Severe Winter Storm and Snowstorm |
| October 2008 | Severe Storm | Severe Storms and Flooding |
| September 2007 | Severe Storm | Severe Storms and Flooding |
| September 2005 | Hurricane | Hurricane Katrina Evacuation |
| April 2004 | Severe Storm | Severe Storms and Tornadoes |
Showing the 10 most recent of 19 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Will County?
Will County has a composite FEMA National Risk Index score of 97.3 out of 100, placing it in the High category and the 97th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Will County?
The three highest-rated hazards are Cold Wave (Very High, $72M EAL), Tornado (Very High, $63M EAL), Riverine Flood (High, $193M EAL). These account for most of the county's expected annual losses.
How does Will County compare to other Illinois counties?
Will County ranks #3 of 102 Illinois counties for overall natural disaster risk, with a high rating.
How many federally declared disasters has Will County had?
FEMA records 19 federal disaster declarations for Will County since 1967, most often 5 for severe storm events and 4 for flood events. The most recent was Severe Storms, Tornadoes, Straight-Line Winds, and Floodng, declared in September 2024.
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. Will County's $348M EAL is a statistical average, not a guarantee for any specific year or address.