FEMA Records
14
Low volume
Ohio · FEMA + NOAA + National Risk Index
Mercer County, OH
14 FEMA disaster declarations (1965-2024), with a FEMA National Risk Index rating of Very Low. Most common hazard: Severe Storm.
- 14
- FEMA declarations
- 10
- Major disasters
- 32
- NRI risk · Very Low
- Severe Storm
- Top hazard
The verdict
Mercer County has a nationally busy FEMA history: 14 declarations, more than 20% of counties in this registry. But the state comparison tempers that reading: the total is 4% below the Ohio county mean. FEMA's separate National Risk Index places the county safer than 32%; that score models loss and vulnerability rather than counting declarations.
- Safer than 32%
- of U.S. counties for FEMA National Risk Index score
- Very Low
- FEMA National Risk Index rating
- 14
- FEMA declarations vs 21 national county avg
- 96
- 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 39107 · Mercer County 14 declarations · rank 2614/3,266
DECL-MID · MAJOR-MID · RANK-LOWER · PHOTO-FINISH · NRI-LOW · ACT-HIGH · TYPE-LEAD · VS-ST-BELOW
- DECL-MID 14
- MAJOR-MID 71%
- RANK-LOWER #2,614
- PHOTO-FINISH Pulaski
- NRI-LOW Very Low
- ACT-HIGH High
- TYPE-LEAD Severe Storm
- VS-ST-BELOW -4%
Nearest declaration peer: Pulaski, IL (0 declaration gap)
FEMA Disaster Declarations Summaries v2 filing stamps for this county register. Read with this county → · Ohio state profile
Mercer County among counties with fewer federal records
FEMA declaration records among Mercer County and nearest peers by total count
- Los Angeles · largest
Los Angeles · largest
88 declarations
- Franklin (city) · near 14
Franklin (city) · near
14 declarations
- Harris · near 14
Harris · near
14 declarations
- Mercer · this county 14
Mercer · this county
14 declarations
- Pulaski · near 14
Pulaski · near
14 declarations
- Ujelang · smallest 1
Ujelang · smallest
1 declarations
What this shows Mercer County carries 14 FEMA declaration records, ranked 2614 of 3,266 counties in this registry.
Mercer County versus quieter counties in this dataset
Mercer County among lower-declaration counties nationally
FEMA disaster declarations, all-time · Mercer County
14 20th percentile higher than 20% 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
Mercer County's FEMA Risk Index score
Which hazard drives modeled loss here?
FEMA's modeled annual dollar loss for Mercer County is led by Riverine Flooding (about $9.2M Expected Annual Loss, Historical Loss Ratio Relatively Moderate), while Earthquake carries the highest National Risk Index rating (Relatively Low). 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 Mercer County's hazard record show?
Reading the federal records together
The NFIP claims register shows a middle-volume loss record here: 96 paid claims, totaling $1.3M. PlainHazard uses 50-499 claims for this descriptive band; FEMA does not publish it as a safety or coverage category. The $14.0K average describes payments on recorded claims only, leaving uninsured damage and properties without a claim outside the measure.
Start with the state benchmark: a Ohio county averages 14.6 federal declaration records, while Mercer County has 14. The gap is 4% 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
FEMA's data shows an elevated National Risk Index composite of 31.6/100 for this county (Very Low rating). Expected Annual Loss comes in at Relatively Low (roughly $18.0M in annualized losses). Social vulnerability (Very Low) and community resilience (Very High) both factor into how that raw exposure plays out on the ground. Even the county's top-rated hazard, Earthquake, only reaches Relatively Low on FEMA's scale, none of the 18 modeled hazards stand out here. FEMA's modeled frequency puts that hazard at roughly once every 488 years here.
55 /100
Historical Activity Index
High historical activity
Mercer County, OH · 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
10/30
14 OpenFEMA declarations, full ingest window (0.7x national county average)
County Disaster Density Moderate
12/25
14 declarations (1.0x state county average of 15)
Major Disaster Share High
18/25
10 of 14 declarations are major disasters (71%)
Hazard Diversity Very High
15/20
6 different disaster types declared in Mercer County
FEMA NRI 8-hazard radar - Mercer 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
71%
Major-heavy
NRI risk score
32
Very Low
Source: FEMA National Risk Index Per-county per-hazard ratings, December 2025 release
How often does each hazard strike Mercer 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 |
|---|---|---|
| Earthquake | Relatively Low | roughly once every 488 years |
| Tornado | Relatively Moderate | roughly once every 3 years |
| Hail | Relatively Low | an average of 3.5 times per year |
| Strong Wind | Relatively Low | an average of 3.5 times per year |
| Ice Storm | Relatively Low | roughly once every 1 years |
| Riverine Flooding | Relatively Low | an average of 2.3 times per year |
| Hurricane | Very Low | roughly once every 87 years |
| Cold Wave | Relatively Low | an average of 4.8 times per year |
| Winter Weather | Relatively Low | an average of 12 times per year |
| Lightning | Relatively Low | an average of 43 times per year |
| Landslide | Very Low | roughly once every 13 years |
| Heat Wave | Very Low | 4 modeled event-days per year |
| Wildfire | Very Low | roughly once every 99,079 years |
Source: FEMA National Risk Index Modeled annualized frequency; drought and heat wave use event-days/year, December 2025 release
Disaster Types
Severe Storm 6
Tornado 3
Biological 2
Hurricane 1
Flood 1
Snowstorm 1
What Severe Storm declarations mean here
Severe Storm is the most frequent declaration type on Mercer County's record, 43% 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 - 10 71.4%
of all 14 declarations
Emergency - 4 28.6%
of all 14 declarations
FEMA Declarations Timeline
| Year | Declarations | |
|---|---|---|
| 2024 | 1 | |
| 2020 | 2 | |
| 2019 | 1 | |
| 2012 | 1 | |
| 2005 | 2 | |
| 2004 | 1 | |
| 2003 | 1 | |
| 1995 | 1 | |
| 1992 | 1 | |
| 1989 | 1 | |
| 1978 | 1 | |
| 1965 | 1 | |
Disaster Declarations
How the 14 FEMA declarations break into federal action codes (DR / EM / FM). Same DISTINCT grain as the table below.
Download these 14 declarations as CSV . FEMA source data is public domain; our derived presentation is CC0.
| DR# | Title | Type | Incident | Date |
|---|---|---|---|---|
| 4777 | TORNADOES | DR | Tornado | 2024-05-02 |
| 4507 | COVID-19 PANDEMIC | DR | Biological | 2020-03-31 |
| 3457 | COVID-19 | EM | Biological | 2020-03-13 |
| 4447 | SEVERE STORMS, STRAIGHT-LINE WINDS, TORNADOES, FLOODING, LANDSLIDES, AND MUDSLIDE | DR | Tornado | 2019-06-18 |
| 3346 | SEVERE STORMS | EM | Severe Storm | 2012-06-30 |
| 3250 | HURRICANE KATRINA EVACUATION | EM | Hurricane | 2005-09-13 |
| 1580 | SEVERE WINTER STORMS, FLOODING, AND MUDSLIDES | DR | Severe Storm | 2005-02-15 |
| 1556 | SEVERE STORMS AND FLOODING | DR | Severe Storm | 2004-09-19 |
| 1478 | SEVERE STORMS AND FLOODING | DR | Severe Storm | 2003-07-15 |
| 1065 | SEVERE STORMS AND FLOODING | DR | Severe Storm | 1995-08-25 |
| 951 | SEVERE STORMS, TORNADOES & FLOODING | DR | Severe Storm | 1992-08-04 |
| 831 | SEVERE STORMS & FLOODING | DR | Flood | 1989-06-10 |
| 3055 | BLIZZARDS & SNOWSTORMS | EM | Snowstorm | 1978-01-26 |
| 191 | TORNADOES & SEVERE STORMS | DR | Tornado | 1965-04-14 |
Storm Events in Ohio
Statewide NOAA context only. PlainHazard does not currently attribute these state totals to Mercer County.
| Storm Type | Events | Fatalities | Injuries | Property Damage |
|---|---|---|---|---|
| Thunderstorm Wind | 6,938 | 6 | 39 | $60.4M |
| Winter Weather | 2,101 | 7 | 42 | $3.3M |
| Hail | 1,749 | 0 | 0 | $673.5K |
| Flood | 1,607 | 9 | 0 | $84.5M |
| Flash Flood | 1,089 | 9 | 7 | $112.2M |
Source: NOAA Storm Events Database State-level aggregated data, 2015-2025
NFIP Flood Insurance Claims
Total Claims
96
Total Paid
$1.3M
Avg Per Claim
$14.0K
Source: FEMA National Flood Insurance Program (NFIP) OpenFEMA Claims Data
FEMA National Risk Index
Overall Risk
Very Low
Score: 31.6/100
Expected Annual Loss
Relatively Low
$18.0M/year
Social Vulnerability
Very Low
Community Resilience
Very High
Hazard Risk Breakdown
Earthquake Relatively Low
Tornado Relatively Moderate
Hail Relatively Low
Strong Wind Relatively Low
Ice Storm Relatively Low
Riverine Flooding Relatively Low
Hurricane Very Low
Cold Wave Relatively Low
Winter Weather Relatively Low
Lightning Relatively Low
Landslide Very Low
Heat Wave Very Low
Wildfire Very Low
Drought No Rating
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: Earthquake
Earthquake is the model's clearest example of a hazard with no season and no warning. Its expected loss is driven less by how often shaking occurs than by how much of the building stock predates modern seismic codes, so exposure can be high in places where nothing has happened for a long time.
Worth noting for Mercer County: the model and the federal record do NOT point at the same hazard. Earthquake carries the highest modeled rating (Relatively Low), 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
Mercer County's closest FEMA peer: Washington County, WI
Comparisons use published FEMA declaration fields plus the National Risk Index composite for Mercer County. Record similarity, not a safety rating.
Closest declaration profiles
Mercer County shows 14 FEMA declarations, led by Severe Storm.
Similar Major-disaster share
Mercer County: 10 of 14 of its declarations are Major.
Similar modeled NRI score
Mercer County: NRI composite 31.6 (Very Low).
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 Mercer County - capture-dated entries only.
Compare beyond this state
Nationwide peers by NRI score & FEMA declaration volume
Two PlainHazard-derived comparison paths for Mercer 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: 31.6 (Very Low).
Similar declaration volume
Nearest out-of-state counties by FEMA declaration count. This county: 14. NRI peers are excluded so the two link sets stay distinct.
Further reading for this county
Understanding disaster data
Mercer County's NFIP claims file (96 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 Mercer County?
The most common disaster type in Mercer County is Severe Storm, with 6 declarations. Other disaster types include Tornado (3), Biological (2), Hurricane (1).
How does Mercer County's FEMA declaration record compare with the Ohio average?
The typical Ohio county has 14.6 FEMA declaration records; Mercer County has 14, or 4% fewer. Against the national county mean of 20.7, this county's total is 32% lower. The comparison is historical and says nothing about the probability of a future event.
How many major FEMA disaster declarations has Mercer County received?
Mercer County has received 10 major disaster declarations, representing 71% of all 14 disaster declarations.
How many flood insurance claims has Mercer County filed?
Mercer County has 96 National Flood Insurance Program (NFIP) claims totaling $1.3M in payments, with an average of $14.0K per claim.
Does FEMA's top risk-rated hazard match the highest Expected Annual Loss in Mercer County?
No. In Mercer County, Earthquake has the highest National Risk Index rating (Relatively Low), while Riverine Flooding leads Expected Annual Loss at about $9.2M. FEMA's risk score and dollar-loss model use different inputs, so the leaders often differ.
What was the worst year for disasters in Mercer County?
The most active year for disaster declarations in Mercer County was 2005, with 2 declarations. The county has FEMA disaster data spanning 1965 to 2024.
What is the FEMA National Risk Index score for Mercer County?
According to the FEMA National Risk Index, Mercer County, Ohio has an overall risk score of 31.6 out of 100 (Very Low). The county's social vulnerability rating is Very Low and community resilience is Very High. The Expected Annual Loss (EAL) score is Relatively Low, representing $18.0M in annualized losses.
Which natural hazard poses the greatest risk to Mercer County?
FEMA's NRI data points to Mercer County as of the latest release is Earthquake (risk rating: Relatively Low). Other significant hazards include Tornado (Relatively Moderate) and Hail (Relatively Low). FEMA's modeled event frequency puts earthquake here at roughly once every 488 years. These scores are based on FEMA's analysis of historical event frequency, 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 Mercer County · vintage 2026-08-25 · Methodology · Ohio profile · Verify with FEMA OpenFEMA · Verify with NOAA Storm Events