FEMA Records
9
Low volume
Illinois · FEMA + NOAA + National Risk Index
Williamson County, IL
9 FEMA disaster declarations (1982-2020), with a FEMA National Risk Index rating of Relatively Moderate. Most common hazard: Severe Storm.
- 9
- FEMA declarations
- 6
- Major disasters
- 86
- NRI risk · Relatively Moderate
- Severe Storm
- Top hazard
The verdict
Start with the local benchmark for Williamson County: 9 FEMA declaration records are 30% below the Illinois county mean, even though the count is higher than 8% of counties in the national registry. On FEMA's distinct National Risk Index model, which combines expected loss with vulnerability and resilience, the county ranks in the riskiest 14%.
- Riskiest 14%
- of U.S. counties for FEMA National Risk Index score
- Relatively Moderate
- FEMA National Risk Index rating
- 9
- FEMA declarations vs 21 national county avg
- 239
- NFIP flood insurance claims filed
FEMA's National Risk Index and its declaration registry are separate measures. This county's registry includes Major Disaster (DR) and Emergency (EM) records; an EM authorizes a narrower set of federal assistance than a DR.
How does Williamson County compare?
Williamson County vs. all counties in this dataset
FEMA disaster declarations, all-time
9 8th percentile higher than 8% of 3,266 counties
Each bar is a band; taller bars hold more counties. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.
Source FEMA Disaster Declarations Summaries v2 · 2026-08-03
Williamson County's FEMA Risk Index score
FEMA National Risk Index composite score vs. the Illinois county average
Which hazard drives modeled loss here?
FEMA's modeled annual dollar loss for Williamson County is led by Earthquake (about $19.6M Expected Annual Loss, Historical Loss Ratio Relatively High), while Strong Wind carries the highest National Risk Index rating (Very High). EAL and risk score use different inputs; they need not agree.
Source: FEMA National Risk Index (December 2025 release) - Expected Annual Loss vs composite risk rating by hazard.
What does Williamson County's hazard record show?
Reading the federal records together
The NFIP claims register shows a middle-volume loss record here: 239 paid claims, totaling $2.1M. PlainHazard uses 50-499 claims for this descriptive band; FEMA does not publish it as a safety or coverage category. The $8.8K average describes payments on recorded claims only, leaving uninsured damage and properties without a claim outside the measure.
Start with the state benchmark: a Illinois county averages 12.9 federal declaration records, while Williamson County has 9. The gap is 30% below that mean. Fewer entries indicate a quieter history of recorded federal actions, not immunity from a hazard and not a prediction about what happens next.
FEMA National Risk Index
This county sits among the highest-risk counties nationally on FEMA's National Risk Index, a composite score of 85.8/100 (Relatively Moderate). Expected Annual Loss is rated Relatively Low (roughly $52.5M in annualized losses). Social vulnerability reads Relatively Moderate and community resilience Relatively High, both critical modifiers of realized harm here. Of the 18 hazards FEMA models, Strong Wind stands out as the sharpest exposure here, rated Very High. FEMA's modeled frequency puts that hazard at an average of 4.1 times per year here, based on 156 historical events on record.
Declaration frequency
The state comparison is the clearest context for Williamson County's moderate federal record. Its 9 declarations sit 30% below the Illinois county mean, with 6 Major Disaster entries among them. 3 records concern Severe Storm, the file's most frequent incident type. Spread across 38 years, the registry rate is 0.2 per year. FEMA reports authorized programs separately from the DR, EM, and FM codes.
46 /100
Historical Activity Index
Moderate historical activity
Williamson County, IL · PlainHazard-derived composite from federal records
This 0–100 index is an explicit PlainHazard composite from FEMA declaration history only on the county surface (this DB has no county-level NOAA damage row) . It is not FEMA's National Risk Index, not a forecast, and not a safety, insurance, or preparedness rating. Open the calculator · Methodology
FEMA Declarations (1953–present) Low
7/30
9 OpenFEMA declarations, full ingest window (0.4x national county average)
County Disaster Density Moderate
9/25
9 declarations (0.7x state county average of 13)
Major Disaster Share High
17/25
6 of 9 declarations are major disasters (67%)
Hazard Diversity High
13/20
5 different disaster types declared in Williamson County
Historical Declaration Activity
Activity Band
Moderate
vs. Illinois Avg
-30%
State avg: 12.9
vs. National Avg
-57%
National avg: 20.7
Avg Per Year
0.2
Over 38 years
FEMA NRI 8-hazard radar - Williamson County
How to read this radar
Each axis: NRI risk rating (Very Low-Very High) on a 0-100 scale. Rounder = broad exposure; spiky = one or two hazards dominate.
Major Disaster share
67%
Major-heavy
NRI risk score
86
Relatively Moderate
Source: FEMA National Risk Index Per-county per-hazard ratings, December 2025 release
How often does each hazard strike Williamson County?
FEMA's National Risk Index models a historical event count and an annualized frequency for each hazard type. Most hazards are expressed as modeled occurrences per year; FEMA expresses drought and heat-wave frequency as event-days per year. These modeled frequencies are not forecasts.
| Hazard | NRI Risk Rating | Recurrence |
|---|---|---|
| Strong Wind | Very High | an average of 4.1 times per year |
| Earthquake | Relatively Moderate | roughly once every 120 years |
| Heat Wave | Relatively Moderate | 10 modeled event-days per year |
| Winter Weather | Relatively High | an average of 7.6 times per year |
| Cold Wave | Relatively Moderate | an average of 1.2 times per year |
| Ice Storm | Relatively Moderate | roughly once every 1 years |
| Tornado | Relatively Moderate | roughly once every 3 years |
| Landslide | Relatively Low | roughly once every 2 years |
| Hail | Relatively Moderate | an average of 3.3 times per year |
| Riverine Flooding | Relatively Low | an average of 2 times per year |
| Lightning | Relatively Moderate | an average of 53 times per year |
| Drought | Relatively Low | 3.2 modeled event-days per year |
| Hurricane | Very Low | roughly once every 45 years |
| Wildfire | Very Low | roughly once every 3,645 years |
Source: FEMA National Risk Index Modeled annualized frequency; drought and heat wave use event-days/year, December 2025 release
Disaster Types
Severe Storm 3
Biological 2
Tornado 2
Hurricane 1
Snowstorm 1
What Severe Storm declarations mean here
Severe Storm is the most frequent declaration type on Williamson County's record, 33% of its declarations. In FEMA's vocabulary this covers convective weather: thunderstorm straight-line winds, large hail, and the multi-day outbreaks that often carry embedded tornadoes. Activity is heaviest in spring and summer, though the season varies by region.
These events behave differently from a hurricane on paper. Damage tends to be distributed along a storm track rather than concentrated on a coastline, and a declaration typically follows an outbreak that crossed several counties over a few days, not a single point of impact. Because the qualifying threshold is the cost of uninsured public and individual losses rather than storm intensity, two similar storms can produce a declaration in one year and none in another.
Declaration counts describe past federal action. They are a record of what was declared, not a forecast of future hazard probability.
Declaration Types
What DR / EM / FM mean
FEMA categorizes declarations as Major Disasters (DR), Emergencies (EM), or Fire Management Assistance (FM).
Major Disaster - 6 66.7%
of all 9 declarations
Emergency - 3 33.3%
of all 9 declarations
FEMA Declarations Timeline
| Year | Declarations | |
|---|---|---|
| 2020 | 2 | |
| 2011 | 1 | |
| 2009 | 1 | |
| 2005 | 2 | |
| 2002 | 1 | |
| 1996 | 1 | |
| 1982 | 1 | |
Disaster Declarations
How the 9 FEMA declarations break into federal action codes (DR / EM / FM). Same DISTINCT grain as the table below.
Download these 9 declarations as CSV . FEMA source data is public domain; our derived presentation is CC0.
| DR# | Title | Type | Incident | Date |
|---|---|---|---|---|
| 4489 | COVID-19 PANDEMIC | DR | Biological | 2020-03-26 |
| 3435 | COVID-19 | EM | Biological | 2020-03-13 |
| 1991 | SEVERE STORMS AND FLOODING | DR | Severe Storm | 2011-06-07 |
| 1850 | SEVERE STORMS, FLOODING, AND TORNADOES | DR | Severe Storm | 2009-07-02 |
| 3230 | HURRICANE KATRINA EVACUATION | EM | Hurricane | 2005-09-07 |
| 3199 | RECORD/NEAR RECORD SNOW | EM | Snowstorm | 2005-02-01 |
| 1416 | SEVERE STORMS, TORNADOES AND FLOODING | DR | Tornado | 2002-05-21 |
| 1112 | SEVERE STORMS AND FLOODING | DR | Severe Storm | 1996-05-06 |
| 660 | SEVERE STORMS & TORNADOES | DR | Tornado | 1982-06-05 |
Storm Events in Illinois
Statewide NOAA context only. PlainHazard does not currently attribute these state totals to Williamson County.
| Storm Type | Events | Fatalities | Injuries | Property Damage |
|---|---|---|---|---|
| Thunderstorm Wind | 7,218 | 9 | 67 | $46.0M |
| Hail | 3,195 | 0 | 0 | $27.1M |
| Winter Weather | 1,363 | 14 | 49 | $1.8M |
| Flood | 1,221 | 14 | 11 | $84.3M |
| Flash Flood | 1,133 | 11 | 3 | $1.1B |
Source: NOAA Storm Events Database State-level aggregated data, 2015-2025
NFIP Flood Insurance Claims
Total Claims
239
Total Paid
$2.1M
Avg Per Claim
$8.8K
Source: FEMA National Flood Insurance Program (NFIP) OpenFEMA Claims Data
FEMA National Risk Index
Overall Risk
Relatively Moderate
Score: 85.8/100
Expected Annual Loss
Relatively Low
$52.5M/year
Social Vulnerability
Relatively Moderate
Community Resilience
Relatively High
Hazard Risk Breakdown
Strong Wind Very High
Earthquake Relatively Moderate
Heat Wave Relatively Moderate
Winter Weather Relatively High
Cold Wave Relatively Moderate
Ice Storm Relatively Moderate
Tornado Relatively Moderate
Landslide Relatively Low
Hail Relatively Moderate
Riverine Flooding Relatively Low
Lightning Relatively Moderate
Drought Relatively Low
Hurricane Very Low
Wildfire Very Low
Source: FEMA National Risk Index (NRI) Ratings reflect relative scores among all US counties. Data: hazards.fema.gov/nri
The model's sharpest exposure here: Strong Wind
Strong Wind covers damaging non-thunderstorm, non-tornadic wind, the kind produced by steep pressure gradients and downslope events. It is a broad, frequent, low-drama hazard: roofs, signage, power lines and high-profile vehicles, spread across a wide area rather than concentrated on a path.
For Williamson County the two measures on this page point the same way: Strong Wind is the county's highest-rated modeled hazard (Very High), and Severe Storm declarations also lead its federal record. Where the model and the declaration history agree, the reading is comparatively straightforward, the hazard is both expected and repeatedly realised.
National Risk Index ratings are modeled estimates of expected annual loss, not predictions of what will happen in any given year.
Data-matched county comparisons
Williamson County's closest FEMA peer: Boone County, MO
Comparisons use published FEMA declaration fields plus the National Risk Index composite for Williamson County. Record similarity, not a safety rating.
Similar modeled NRI score
Williamson County: NRI composite 85.8 (Relatively Moderate).
Similar Major-disaster share
Williamson County: 6 of 9 of its declarations are Major.
Closest declaration profiles
Williamson County shows 9 FEMA declarations, led by Severe Storm.
How these peers are chosen
Cohort: Published U.S. county equivalents outside the source state or territory. Each metric keeps six ETL candidates; three unique destinations are shown after de-duplicating across axes. Declaration-volume ranking combines count and Major-disaster share and prefers a different leading incident type; Major-share ranks the Major fraction adjusted for volume; NRI ranks the modeled composite score only.
Retained FEMA snapshot feed for Williamson County - capture-dated entries only.
Further reading for this county
Understanding disaster data
Williamson County's NFIP claims file (239 claims) and FEMA declaration history measure different federal records - this guide separates them from modeled NRI risk.
More PlainHazard guides
- Most disaster-prone counties - U.S. counties ranked by FEMA declaration totals.
- Understanding disaster data - declarations vs storm events vs NRI scores.
- Preparing for natural disasters - household checklist (not county-specific advice).
Related
Frequently Asked Questions
What is the most common disaster type in Williamson County?
The most common disaster type in Williamson County is Severe Storm, with 3 declarations. Other disaster types include Biological (2), Tornado (2), Hurricane (1).
How does Williamson County's FEMA declaration record compare with the Illinois average?
The typical Illinois county has 12.9 FEMA declaration records; Williamson County has 9, or 30% fewer. Against the national county mean of 20.7, this county's total is 57% lower. The comparison is historical and says nothing about the probability of a future event.
How many major FEMA disaster declarations has Williamson County received?
Williamson County has received 6 major disaster declarations, representing 67% of all 9 disaster declarations.
How many flood insurance claims has Williamson County filed?
Williamson County has 239 National Flood Insurance Program (NFIP) claims totaling $2.1M in payments, with an average of $8.8K per claim.
Does FEMA's top risk-rated hazard match the highest Expected Annual Loss in Williamson County?
No. In Williamson County, Strong Wind has the highest National Risk Index rating (Very High), while Earthquake leads Expected Annual Loss at about $19.6M. FEMA's risk score and dollar-loss model use different inputs, so the leaders often differ.
What was the worst year for disasters in Williamson County?
The most active year for disaster declarations in Williamson County was 2005, with 2 declarations. The county has FEMA disaster data spanning 1982 to 2020.
What is the FEMA National Risk Index score for Williamson County?
According to the FEMA National Risk Index, Williamson County, Illinois has an overall risk score of 85.8 out of 100 (Relatively Moderate). On social vulnerability the county rates Relatively Moderate; on community resilience, Relatively High. The Expected Annual Loss (EAL) score is Relatively Low, representing $52.5M in annualized losses.
Which natural hazard poses the greatest risk to Williamson County?
The top hazard flagged by FEMA's NRI for Williamson County is Strong Wind (risk rating: Very High). Other significant hazards include Earthquake (Relatively Moderate) and Heat Wave (Relatively Moderate). FEMA's modeled event frequency puts strong wind here at an average of 4.1 times per year, drawn from 156 historical events on record. The underlying methodology weighs historical event frequency against exposed assets and community vulnerability.
Data Sources & Methodology
Disaster declaration data comes from the FEMA OpenFEMA Disaster Declarations Summaries v2 API, which includes all federally declared disasters, emergencies, and fire management assistance grants.
Storm event data is sourced from the NOAA Storm Events Database (2015-2025), which tracks significant weather events including thunderstorms, tornadoes, floods, and winter storms.
Flood insurance data comes from the FEMA National Flood Insurance Program (NFIP) OpenFEMA claims dataset.
This data is provided for informational purposes only. FEMA disaster declarations represent federal response actions and may not capture all local emergencies or weather events.
What this means for Williamson County
Against a Illinois county mean of 13 declarations, Williamson County, IL records 9, or 30% fewer. PlainHazard classifies that historical total as moderate activity.
- Major Disaster is the largest group (6 of 9) in a declaration history that remains below its state benchmark; frequency here is not a forecast. Illinois overview
- Nationally the county exceeds 8% of recorded county totals, but its own Illinois benchmark is higher. The ranking keeps those two contexts separate. Most-disaster rankings
- Use the data guide to separate this mid-volume insurance-claims file from declaration counts and modeled NRI risk. Disaster-data guide
A below-average federal record is not a safety guarantee. Use National Weather Service alerts and local emergency-management notices for present conditions, not this historical comparison.
PlainHazard derives this profile from FEMA's Disaster Declarations Summaries and National Risk Index data. The declaration comparison covers 3,266 U.S. counties and county equivalents in this database, refreshed as of 2026-08-03. Read our methodology - how this data is sourced, computed, and verified.
All federal data sources used on this page
- FEMA OpenFEMA, Disaster Declarations Summaries v2 - all federally-declared disasters for this county. fema.gov/openfema/disaster-declarations
- FEMA National Risk Index (NRI) - per-county per-hazard risk ratings and expected annual loss. hazards.fema.gov/nri
- NOAA NCEI Storm Events Database - state-level storm/severe-weather event records, 2015-2025. ncdc.noaa.gov/stormevents
Data sourced from official public datasets. See our methodology for details. Retrieved and formatted by PlainHazard Editorial
Verify with FEMA → · Verify with FEMA NRI → · Verify with NOAA →
Every figure on PlainHazard is rendered directly from FEMA federal disaster data, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or national statistics report, the data & editorial changelog, or report a data error.