Natural disaster risk in Williamson County, Illinois
Illinois · population 67,101 · FIPS 17199
Overall: relatively moderate risk
Williamson County has a composite risk score of 85.8 out of 100 — higher than 85% of US counties. It ranks 17 of 102 in Illinois (1 = highest risk). Its highest-rated hazards are strong wind, winter weather, earthquake.
Drought now: Yes: D1 Moderate Drought, 1 week
Yes. On the U.S. Drought Monitor map valid 13 October 2026, 100% of Williamson County is in D1 Moderate Drought. Some of it has been at D1 or worse for 1 week so far.
Drought in Williamson County: the last 52 weeks · droughtmonitor.unl.edu
The U.S. Drought Monitor is jointly produced by the National Drought Mitigation Center at the University of Nebraska-Lincoln, the United States Department of Agriculture, the National Oceanic and Atmospheric Administration and the National Aeronautics and Space Administration. Map courtesy of NDMC.
Risk, loss, vulnerability and resilience
| Measure | Rating and score |
|---|---|
| Overall risk Expected annual loss, adjusted for social vulnerability and community resilience. |
Relatively moderate 85.8 |
| Expected annual loss About $52.5 million a year, on average, across all 18 hazards. |
Relatively low 84.4 |
| Social vulnerability Higher means people may find it harder to prepare and recover. |
Relatively moderate 55.4 |
| Community resilience Higher means a stronger ability to prepare, adapt and recover. |
Relatively high 78.2 |
Risk by hazard
FEMA's risk rating for each of 18 natural hazards in Williamson County, highest first. "Not applicable" means the hazard is not modelled here.
| Hazard | Risk rating and score |
|---|---|
| Strong wind | Very high 99 |
| Winter weather | Relatively high 89 |
| Earthquake | Relatively moderate 96 |
| Heat wave | Relatively moderate 90 |
| Cold wave | Relatively moderate 86 |
| Ice storm | Relatively moderate 81 |
| Tornado | Relatively moderate 80 |
| Hail | Relatively moderate 78 |
| Lightning | Relatively moderate 67 |
| Landslide | Relatively low 79 |
| Inland (riverine) flooding | Relatively low 69 |
| Drought | Relatively low 54 |
| Hurricane | Very low 44 |
| Wildfire | Very low 14 |
| Avalanche | Not applicable |
| Coastal flooding | Not applicable |
| Tsunami | Not applicable |
| Volcanic activity | Not applicable |
FEMA disaster declarations for Williamson County
Federal declarations that designated Williamson County, since 1 Jan 2024 (the period this site keeps from OpenFEMA). Older declarations are in FEMA's own dataset.
Not since 1 Jan 2024: no FEMA disaster declaration in the records this site read names Williamson County.
All FEMA declarations in Illinois, with estimated apply-by dates · Open FEMA deadlines
This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s). Dataset: Disaster Declarations Summaries - v2.
How to read these ratings
- Ratings run in five steps: very low, relatively low, relatively moderate, relatively high and very high. They compare a county with every other US county; they are not a measure of danger on their own.
- Scores run from 0 to 100 and are national percentiles. The bar shows the score: a score of 80 means a higher value than 80% of US counties.
- Overall risk combines the expected annual loss with social vulnerability and community resilience.
- Expected annual loss is the average yearly loss to buildings, people and agriculture the model expects from all 18 hazards.
- Social vulnerability describes how hard it may be for people to prepare for and recover from a disaster. Higher is worse.
- Community resilience describes a community's ability to prepare, adapt and recover. Higher is better.
- "Not applicable" means FEMA does not model that hazard there (for example, hurricanes far inland).
About this data
Source: FEMA National Risk Index, version 1.20, released December 2025, published by the Federal Emergency Management Agency (US public domain). About the National Risk Index. The index is a model of relative risk built from historical hazard records, what is exposed and community factors. It is not a forecast, it does not describe any single property, and it is not insurance or financial advice. For decisions about a specific address, check FEMA's flood maps and your local emergency management office.
Questions
What is the natural disaster risk in Williamson County, Illinois?
FEMA's National Risk Index rates the overall risk in Williamson County as relatively moderate, with a score of 85.8 out of 100 (higher than 85% of US counties). That is a comparison with other US counties, not a forecast.
What are the biggest natural hazards in Williamson County?
The hazards rated highest for Williamson County are strong wind (very high), winter weather (relatively high), earthquake (relatively moderate).
What is the flood risk in Williamson County?
FEMA rates inland (river and rain) flooding risk in Williamson County as relatively low. For a specific property, check the FEMA flood map and your local floodplain office.
Has Williamson County had a FEMA disaster declaration?
Not since 1 Jan 2024: no FEMA disaster declaration in the records this site read names Williamson County.
Is Williamson County in a drought?
Yes. On the U.S. Drought Monitor map valid 13 October 2026, 100% of Williamson County is in D1 Moderate Drought. Some of it has been at D1 or worse for 1 week so far.
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