FEMA Records
1
Total declarations
Ohio · FEMA + NOAA + National Risk Index
Mercer County, OH
1 FEMA disaster declarations (2024–2024), with a FEMA National Risk Index rating of Very Low. Most common hazard: Tornado.
- 1
- FEMA declarations
- 1
- Major disasters
- 32
- NRI risk · Very Low
- Tornado
- Top hazard
The verdict
Mercer County ranks safer than 32% of U.S. counties for FEMA-modeled hazard risk, with more federally declared disasters than 0% of the 2,791 counties FEMA tracks. FEMA rates the county's overall risk as Very Low, based on 1 federal disaster declarations recorded since 2024, most often tornado, 74% below the national county average of 4.
- Safer than 32%
- of U.S. counties for FEMA National Risk Index score
- Very Low
- FEMA National Risk Index rating
- 1
- FEMA declarations vs 4 national county avg
- 1
- tornado declarations, the most common hazard here
FEMA's National Risk Index score reflects expected annual loss, social vulnerability, and community resilience; the declaration count above reflects only Presidentially declared disasters, not every hazard event.
How does Mercer County compare?
Mercer County vs. every U.S. county
FEMA disaster declarations, all-time
1 0th percentile higher than 0% of 2,791 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 · 2026-07-25
Mercer County's FEMA Risk Index score
FEMA National Risk Index composite score vs. the Ohio county average
How disaster-prone is Mercer County?
Declaration frequency
Mercer County, Ohio has recorded 1 FEMA disaster declarations between 2024 and 2024, of which 1 were classified as Major Disaster declarations (DR) requiring federal individual and public assistance. That puts the county's average at - declarations per year, or roughly 0% above the Ohio county average of 1.0 and 74% below the national county average of 3.8. The dominant disaster type on record is Tornado, with 1 of 1 declarations falling under this category.
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.
Flood exposure & the bottom line
Taken together, Mercer County's federal disaster history is about as quiet as U.S. counties get, a very low relative risk level on this measure.
Risk Assessment
Risk Level
Very Low
vs. Ohio Avg
+0%
State avg: 1.0
vs. National Avg
-74%
National avg: 3.8
Avg Per Year
-
-
FEMA NRI 8-hazard radar - Mercer County
How to read this radar
The radar plots Mercer County's relative exposure to the eight headline natural hazards used by the FEMA National Risk Index. Each axis is the qualitative NRI risk rating (Very Low through Very High) re-expressed on a 0-100 scale so that the polygon shape lets you compare a county against another at a glance. A rounder polygon means broad multi-hazard exposure; a spiky polygon means one or two dominant hazards drive most of the modeled risk.
NRI Source
FEMA 2023
Latest NRI release
County FIPS
39107
OH state code
Source: FEMA National Risk Index FEMA National Risk Index Per-county per-hazard ratings, 2023 release
Disaster Types
Tornado 1
Declaration Types
What DR / EM / FM mean
FEMA categorizes declarations as Major Disasters (DR), Emergencies (EM), or Fire Management Assistance (FM).
Major Disaster - 1 100.0%
of all 1 declarations
FEMA Declarations Timeline
| Year | Declarations | |
|---|---|---|
| 2024 | 1 | |
Disaster Declarations
| DR# | Title | Type | Incident | Date |
|---|---|---|---|---|
| 4777 | TORNADOES | DR | Tornado | 2024-05-02 |
Storm Events in Ohio
| Storm Type | Events | Fatalities | Injuries | Property Damage |
|---|---|---|---|---|
| Thunderstorm Wind | 8,363 | 6 | 41 | $67.6M |
| Winter Weather | 2,463 | 7 | 42 | $3.3M |
| Hail | 2,044 | 0 | 0 | $1.0M |
| Flood | 1,958 | 9 | 0 | $86.1M |
| Flash Flood | 1,267 | 10 | 7 | $121.0M |
Source: NOAA Storm Events Database NOAA Storm Events Database State-level aggregated data, 2015–2025
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
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) FEMA National Risk Index (NRI) Ratings reflect relative scores among all US counties. Data: hazards.fema.gov/nri
Counties with Similar Risk in Ohio
Disaster Preparedness Guides
Related
Frequently Asked Questions
How many natural disasters has Mercer County, Ohio had?
Mercer County, Ohio has received 1 FEMA disaster declarations from 2024 to 2024. Of these, 1 were major disaster declarations.
What is the most common disaster type in Mercer County?
The most common disaster type in Mercer County is Tornado, with 1 declaration.
How does Mercer County's disaster risk compare to the Ohio average?
Mercer County has 1 disaster declarations, which is 0% higher than the Ohio county average of 1.0 declarations. Compared to the national county average of 3.8, it is 74% lower.
How many major FEMA disaster declarations has Mercer County received?
Mercer County has received 1 major disaster declaration, representing 100% of all 1 disaster declarations. Major disaster declarations typically involve significant damage requiring federal assistance.
What types of storms are most common in Ohio?
The most common storm types in Ohio include Thunderstorm Wind (8,363 events), Winter Weather (2,463 events), Hail (2,044 events). NOAA storm event data covers severe weather from 2015 to 2025.
What is the overall disaster risk level for Mercer County?
Mercer County has just 1 FEMA disaster declaration on record, placing it in the very-low-risk band, among the quieter counties in FEMA's declaration history.
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?
Based on FEMA NRI data, the highest-risk natural hazard in Mercer County is Earthquake (risk rating: Relatively Low). Other significant hazards include Tornado (Relatively Moderate) and Hail (Relatively Low). 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.
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 Mercer County
Mercer County, OH runs 0% above the Ohio county average for federal disaster declarations (1 vs 1), a very low historical load overall.
- Its most common federal declaration type is major disaster (1 of 1) - know the hazards most likely here before they happen. Ohio overview
- See how this county ranks against the rest of the country for disaster frequency. Most-disaster rankings
- Read how to read FEMA declarations, NRI risk scores, and what they do and don't tell you. Disaster-data guide
Historical declaration counts describe past federal response, not a forecast. For current threats, follow the National Weather Service and local officials; in an emergency call 911.
According to the Federal Emergency Management Agency, this profile draws on 2,791 tracked U.S. counties in FEMA's Disaster Declarations Summaries dataset, refreshed as of 2026-07-25. 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. This page draws directly on FEMA federal disaster data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or national statistics report, or report a data error.