FEMA Records
16
Below median
Tennessee · FEMA + NOAA + National Risk Index
Williamson County, TN
16 FEMA disaster declarations (1974-2026), with a FEMA National Risk Index rating of Relatively Moderate. Most common hazard: Severe Storm.
- 16
- FEMA declarations
- 12
- Major disasters
- 85
- NRI risk · Relatively Moderate
- Severe Storm
- Top hazard
The verdict
Williamson County has a nationally busy FEMA history: 16 declarations, more than 27% of counties in this registry. But the state comparison tempers that reading: the total is 25% below the Tennessee county mean. FEMA's separate National Risk Index places the county in the riskiest 15%; that score models loss and vulnerability rather than counting declarations.
- Riskiest 15%
- of U.S. counties for FEMA National Risk Index score
- Relatively Moderate
- FEMA National Risk Index rating
- 16
- FEMA declarations vs 21 national county avg
- 1,099
- 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.
FEMA OpenFEMA declaration desk
County FIPS 47187 · Williamson County 16 declarations · rank 2224/3,266
DECL-MID · MAJOR-MID · RANK-LOWER · PHOTO-FINISH · NRI-MID · ACT-HIGH · TYPE-LEAD · VS-ST-BELOW
- DECL-MID 16
- MAJOR-MID 75%
- RANK-LOWER #2,224
- PHOTO-FINISH Greene
- NRI-MID 85
- ACT-HIGH High
- TYPE-LEAD Severe Storm
- VS-ST-BELOW -25%
Nearest declaration peer: Greene, GA (0 declaration gap)
FEMA Disaster Declarations Summaries v2 filing stamps for this county register. Read with this county → · Tennessee state profile
Williamson County among counties with fewer federal records
FEMA declaration records among Williamson County and nearest peers by total count
- Los Angeles · largest
Los Angeles · largest
88 declarations
- Frontier · near 16
Frontier · near
16 declarations
- Greene · near 16
Greene · near
16 declarations
- Terrell · near 16
Terrell · near
16 declarations
- Williamson · this county 16
Williamson · this county
16 declarations
- Ujelang · smallest 1
Ujelang · smallest
1 declarations
What this shows Williamson County carries 16 FEMA declaration records, ranked 2224 of 3,266 counties in this registry.
Williamson County versus quieter counties in this dataset
Williamson County among lower-declaration counties nationally
FEMA disaster declarations, all-time · Williamson County
16 27th percentile higher than 27% 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 · 2026-08-25
Williamson County's FEMA Risk Index score
Which hazard drives modeled loss here?
FEMA's modeled annual dollar loss for Williamson County is led by Riverine Flooding (about $57.0M Expected Annual Loss, Historical Loss Ratio Relatively High), while Cold Wave carries the highest National Risk Index rating (Relatively 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
FEMA's NFIP table contains a substantial paid-claim history for this county: 1,099 claims and $31.0M in payments. PlainHazard labels 500 or more claims a heavy registry record; that is a reporting bucket, not an official FEMA risk grade. The average paid claim was $28.2K. NFIP totals exclude uninsured flood losses and do not measure how many properties currently carry a policy.
Start with the state benchmark: a Tennessee county averages 21.4 federal declaration records, while Williamson County has 16. The gap is 25% 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 85.1/100 (Relatively Moderate). Expected Annual Loss is rated Relatively Moderate (roughly $98.0M in annualized losses). Social vulnerability reads Very Low and community resilience Very High, both critical modifiers of realized harm here. Of the 18 hazards FEMA models, Cold Wave stands out as the sharpest exposure here, rated Relatively High. FEMA's modeled frequency puts that hazard at an average of 1.2 times per year here, based on 22 historical events on record.
55 /100
Historical Activity Index
High historical activity
Williamson County, TN · 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) Moderate
12/30
16 OpenFEMA declarations, full ingest window (0.8x national county average)
County Disaster Density Moderate
9/25
16 declarations (0.7x state county average of 21)
Major Disaster Share Very High
19/25
12 of 16 declarations are major disasters (75%)
Hazard Diversity Very High
15/20
6 different disaster types declared in Williamson County
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
75%
Mostly major
NRI risk score
85
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 |
|---|---|---|
| Cold Wave | Relatively High | an average of 1.2 times per year |
| Earthquake | Relatively Low | roughly once every 298 years |
| Strong Wind | Relatively High | an average of 6.1 times per year |
| Tornado | Relatively Moderate | roughly once every 2 years |
| Riverine Flooding | Relatively Moderate | an average of 2.2 times per year |
| Winter Weather | Relatively Moderate | an average of 5.2 times per year |
| Ice Storm | Relatively High | roughly once every 2 years |
| Heat Wave | Relatively Low | 4.9 modeled event-days per year |
| Landslide | Very Low | roughly once every 1 years |
| Lightning | Relatively Low | an average of 61 times per year |
| Hail | Relatively Low | an average of 3.5 times per year |
| Hurricane | Very Low | roughly once every 62 years |
| Wildfire | Very Low | roughly once every 21,258 years |
| Drought | Relatively Low | 9.6 modeled event-days per year |
Source: FEMA National Risk Index Modeled annualized frequency; drought and heat wave use event-days/year, December 2025 release
Disaster Types
Severe Storm 8
Winter Storm 2
Tornado 2
Biological 2
Hurricane 1
Flood 1
What Severe Storm declarations mean here
Severe Storm is the most frequent declaration type on Williamson County's record, 50% 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 - 12 75.0%
of all 16 declarations
Emergency - 4 25.0%
of all 16 declarations
FEMA Declarations Timeline
| Year | Declarations | |
|---|---|---|
| 2026 | 2 | |
| 2025 | 1 | |
| 2021 | 1 | |
| 2020 | 2 | |
| 2010 | 1 | |
| 2008 | 1 | |
| 2005 | 1 | |
| 2003 | 1 | |
| 1999 | 1 | |
| 1998 | 1 | |
| 1994 | 1 | |
| 1979 | 1 | |
| 1975 | 1 | |
| 1974 | 1 | |
Disaster Declarations
How the 16 FEMA declarations break into federal action codes (DR / EM / FM). Same DISTINCT grain as the table below.
Download these 16 declarations as CSV . FEMA source data is public domain; our derived presentation is CC0.
| DR# | Title | Type | Incident | Date |
|---|---|---|---|---|
| 4898 | SEVERE WINTER STORM | DR | Winter Storm | 2026-02-06 |
| 3635 | SEVERE WINTER STORM | EM | Winter Storm | 2026-01-24 |
| 3625 | SEVERE STORMS, STRAIGHT-LINE WINDS, TORNADOES, AND FLOODING | EM | Severe Storm | 2025-04-02 |
| 4601 | SEVERE STORMS, TORNADOES, AND FLOODING | DR | Tornado | 2021-05-08 |
| 4514 | COVID-19 PANDEMIC | DR | Biological | 2020-04-02 |
| 3473 | COVID-19 | EM | Biological | 2020-03-13 |
| 1909 | SEVERE STORMS, FLOODING, STRAIGHT-LINE WINDS, AND TORNADOES | DR | Severe Storm | 2010-05-04 |
| 1745 | SEVERE STORMS, TORNADOES, STRAIGHT-LINE WINDS, AND FLOODING | DR | Severe Storm | 2008-02-07 |
| 3217 | HURRICANE KATRINA EVACUATION | EM | Hurricane | 2005-09-05 |
| 1464 | SEVERE STORMS, TORNADOES, AND FLOODING | DR | Severe Storm | 2003-05-08 |
| 1275 | SEVERE STORMS, TORNADOES AND FLOODING | DR | Severe Storm | 1999-05-12 |
| 1215 | SEVERE STORMS, TORNADOES AND FLOODING | DR | Severe Storm | 1998-04-20 |
| 1010 | SEVERE WINTER ICE STORM,FLASH FLOODING | DR | Severe Storm | 1994-02-28 |
| 585 | SEVERE STORMS, TORNADOES & FLOODING | DR | Severe Storm | 1979-05-07 |
| 459 | SEVERE STORMS & FLOODING | DR | Flood | 1975-03-22 |
| 424 | TORNADOES | DR | Tornado | 1974-04-04 |
Storm Events in Tennessee
Statewide NOAA context only. PlainHazard does not currently attribute these state totals to Williamson County.
| Storm Type | Events | Fatalities | Injuries | Property Damage |
|---|---|---|---|---|
| Thunderstorm Wind | 6,558 | 22 | 58 | $107.0M |
| Hail | 1,690 | 0 | 0 | $545.5K |
| Heat | 1,343 | 9 | 15 | $0 |
| Flash Flood | 1,264 | 55 | 3 | $334.4M |
| Winter Weather | 1,088 | 5 | 0 | $261.0K |
Source: NOAA Storm Events Database State-level aggregated data, 2015-2025
NFIP Flood Insurance Claims
Total Claims
1,099
Total Paid
$31.0M
Avg Per Claim
$28.2K
Source: FEMA National Flood Insurance Program (NFIP) OpenFEMA Claims Data
FEMA National Risk Index
Overall Risk
Relatively Moderate
Score: 85.1/100
Expected Annual Loss
Relatively Moderate
$98.0M/year
Social Vulnerability
Very Low
Community Resilience
Very High
Hazard Risk Breakdown
Cold Wave Relatively High
Earthquake Relatively Low
Strong Wind Relatively High
Tornado Relatively Moderate
Riverine Flooding Relatively Moderate
Winter Weather Relatively Moderate
Ice Storm Relatively High
Heat Wave Relatively Low
Landslide Very Low
Lightning Relatively Low
Hail Relatively Low
Hurricane Very Low
Wildfire Very Low
Drought Relatively 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: Cold Wave
Cold Wave measures exposure to extreme cold rather than to snow. Its harm is concentrated in health effects, burst infrastructure and energy demand spikes, and it falls hardest where the building stock and the grid were not built with sustained cold in mind.
Worth noting for Williamson County: the model and the federal record do NOT point at the same hazard. Cold Wave carries the highest modeled rating (Relatively High), while the county's declaration history is led by Severe Storm. That is not a contradiction, the two measure genuinely different things. Declarations record federal ACTION, which requires damage costly enough to exceed state and local capacity; the Risk Index models EXPECTED annual loss across all 18 hazards whether or not any declaration ever followed. A hazard can be the county's largest modeled exposure and never once have driven a declaration.
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: Jefferson County, AR
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 85.1 (Relatively Moderate).
Similar Major-disaster share
Williamson County: 12 of 16 of its declarations are Major.
Closest declaration profiles
Williamson County shows 16 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.
Compare beyond this state
Nationwide peers by NRI score & FEMA declaration volume
Two PlainHazard-derived comparison paths for Williamson County: nearest out-of-state National Risk Index composite and nearest FEMA declaration count (floor ≥5 records). Record similarity only, not a forecast of the next hazard.
Similar NRI composite
Nearest out-of-state counties by FEMA NRI score. This county: 85.1 (Relatively Moderate).
Similar declaration volume
Nearest out-of-state counties by FEMA declaration count. This county: 16. NRI peers are excluded so the two link sets stay distinct.
Further reading for this county
Understanding disaster data
Williamson County's NFIP claims file (1,099 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).
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 8 declarations. Other disaster types include Winter Storm (2), Tornado (2), Biological (2).
How does Williamson County's FEMA declaration record compare with the Tennessee average?
The typical Tennessee county has 21.4 FEMA declaration records; Williamson County has 16, or 25% fewer. Against the national county mean of 20.7, this county's total is 23% 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 12 major disaster declarations, representing 75% of all 16 disaster declarations.
How many flood insurance claims has Williamson County filed?
Williamson County has 1,099 National Flood Insurance Program (NFIP) claims totaling $31.0M in payments, with an average of $28.2K per claim.
Does FEMA's top risk-rated hazard match the highest Expected Annual Loss in Williamson County?
No. In Williamson County, Cold Wave has the highest National Risk Index rating (Relatively High), while Riverine Flooding leads Expected Annual Loss at about $57.0M. 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 2020, with 2 declarations. The county has FEMA disaster data spanning 1974 to 2026.
What is the FEMA National Risk Index score for Williamson County?
According to the FEMA National Risk Index, Williamson County, Tennessee has an overall risk score of 85.1 out of 100 (Relatively Moderate). Social vulnerability here rates Very Low, while community resilience comes in at Very High. The Expected Annual Loss (EAL) score is Relatively Moderate, representing $98.0M in annualized losses.
Which natural hazard poses the greatest risk to Williamson County?
The top hazard flagged by FEMA's NRI for Williamson County as of the latest release is Cold Wave (risk rating: Relatively High). Other significant hazards include Earthquake (Relatively Low) and Strong Wind (Relatively High). FEMA's modeled event frequency puts cold wave here at an average of 1.2 times per year, drawn from 22 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.
FEMA OpenFEMA declarations + NRI for Williamson County · vintage 2026-08-25 · Methodology · Tennessee profile · Verify with FEMA OpenFEMA · Verify with NOAA Storm Events