FEMA Records
13
Low volume
Pennsylvania · FEMA + NOAA + National Risk Index
Mercer County, PA
13 FEMA disaster declarations (1972-2020), with a FEMA National Risk Index rating of Relatively Low. Most common hazard: Hurricane.
- 13
- FEMA declarations
- 8
- Major disasters
- 78
- NRI risk · Relatively Low
- Hurricane
- Top hazard
The verdict
Mercer County has a nationally busy FEMA history: 13 declarations, more than 17% of counties in this registry. But the state comparison tempers that reading: the total is 30% below the Pennsylvania county mean. FEMA's separate National Risk Index places the county in the riskiest 22%; that score models loss and vulnerability rather than counting declarations.
- Riskiest 22%
- of U.S. counties for FEMA National Risk Index score
- Relatively Low
- FEMA National Risk Index rating
- 13
- FEMA declarations vs 21 national county avg
- 120
- 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 Mercer County compare?
Mercer County vs. all counties in this dataset
FEMA disaster declarations, all-time
13 17th percentile higher than 17% 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
Mercer County's FEMA Risk Index score
FEMA National Risk Index composite score vs. the Pennsylvania county average
What does Mercer County's hazard record show?
Reading the federal records together
The NFIP claims register shows a middle-volume loss record here: 120 paid claims, totaling $880.0K. PlainHazard uses 50-499 claims for this descriptive band; FEMA does not publish it as a safety or coverage category. The $7.3K average describes payments on recorded claims only, leaving uninsured damage and properties without a claim outside the measure.
Start with the state benchmark: a Pennsylvania county averages 18.6 federal declaration records, while Mercer County has 13. 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 77.7/100 (Relatively Low). Expected Annual Loss is rated Relatively Low (roughly $34.1M in annualized losses). Social vulnerability reads Relatively Moderate and community resilience Relatively High, both critical modifiers of realized harm here. Among the 18 modeled hazards, Riverine Flooding carries the county's highest rating, a mid-range Relatively Moderate. FEMA's modeled frequency puts that hazard at an average of 2.5 times per year here, based on 70 historical events on record.
Declaration frequency
Nationally, Mercer County's 13 FEMA records form a high-volume history; within Pennsylvania, however, the count is 30% below the county mean. 8 entries carry the Major Disaster classification. The largest incident group is Hurricane, appearing 3 times. The full 48-year record averages 0.3 declarations annually. A DR label alone does not say whether Individual Assistance, Public Assistance, or both followed.
48 /100
Historical Activity Index
Moderate historical activity
Mercer County, PA · 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
9/30
13 OpenFEMA declarations, full ingest window (0.6x national county average)
County Disaster Density Moderate
9/25
13 declarations (0.7x state county average of 19)
Major Disaster Share High
15/25
8 of 13 declarations are major disasters (62%)
Hazard Diversity Very High
15/20
6 different disaster types declared in Mercer County
Historical Declaration Activity
Activity Band
High
vs. Pennsylvania Avg
-30%
State avg: 18.6
vs. National Avg
-37%
National avg: 20.7
Avg Per Year
0.3
Over 48 years
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
62%
Major-heavy
NRI risk score
78
Relatively 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 |
|---|---|---|
| Riverine Flooding | Relatively Moderate | an average of 2.5 times per year |
| Lightning | Relatively High | an average of 40 times per year |
| Winter Weather | Relatively Moderate | an average of 17 times per year |
| Hail | Relatively Moderate | an average of 3.8 times per year |
| Strong Wind | Relatively Moderate | an average of 2.3 times per year |
| Hurricane | Relatively Low | roughly once every 42 years |
| Tornado | Relatively Low | roughly once every 4 years |
| Earthquake | Very Low | roughly once every 1,672 years |
| Landslide | Very Low | roughly once every 5 years |
| Ice Storm | Relatively Low | roughly once every 2 years |
| Wildfire | Very Low | roughly once every 18,232 years |
| Heat Wave | Very Low | 1.1 modeled event-days per year |
| Cold Wave | Very Low | an average of 3.6 times per year |
Source: FEMA National Risk Index Modeled annualized frequency; drought and heat wave use event-days/year, December 2025 release
Disaster Types
Hurricane 3
Flood 3
Biological 2
Severe Storm 2
Snowstorm 2
Tornado 1
What Hurricane declarations mean here
Hurricane is the most frequent declaration type on Mercer County's federal record, 23% of its declarations. Atlantic tropical systems run on a defined season, 1 June to 30 November, with most activity concentrated between August and October; Pacific and territorial basins run on their own calendars. A single named storm routinely produces one declaration number covering a long corridor of counties at once, well inland as well as on the coast, which is why an affected county's count can jump by several in one year without several separate events having occurred.
One practical distinction matters when reading these records: a tropical declaration usually bundles wind, storm surge and inland rainfall flooding under a single incident, but the insurance behind them is split. Wind damage falls to property insurers, while flood and surge damage is covered only under a separate National Flood Insurance Program policy. That is why a county can show heavy declaration activity and a comparatively small NFIP claims record, or the reverse.
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 - 8 61.5%
of all 13 declarations
Emergency - 5 38.5%
of all 13 declarations
FEMA Declarations Timeline
| Year | Declarations | |
|---|---|---|
| 2020 | 2 | |
| 2013 | 1 | |
| 2005 | 1 | |
| 2004 | 2 | |
| 2003 | 1 | |
| 1996 | 1 | |
| 1993 | 1 | |
| 1985 | 1 | |
| 1981 | 1 | |
| 1977 | 1 | |
| 1972 | 1 | |
Disaster Declarations
How the 13 FEMA declarations break into federal action codes (DR / EM / FM). Same DISTINCT grain as the table below.
Download these 13 declarations as CSV . FEMA source data is public domain; our derived presentation is CC0.
| DR# | Title | Type | Incident | Date |
|---|---|---|---|---|
| 4506 | COVID-19 PANDEMIC | DR | Biological | 2020-03-30 |
| 3441 | COVID-19 | EM | Biological | 2020-03-13 |
| 3356 | HURRICANE SANDY | EM | Hurricane | 2012-10-29 |
| 3235 | HURRICANE KATRINA | EM | Hurricane | 2005-09-10 |
| 1555 | SEVERE STORMS AND FLOODING ASSOCIATED WITH TROPICAL DEPRESSION FRANCES | DR | Severe Storm | 2004-09-19 |
| 1557 | TROPICAL DEPRESSION IVAN | DR | Hurricane | 2004-09-19 |
| 1485 | SEVERE STORMS, TORNADOES, AND FLOODING | DR | Severe Storm | 2003-08-23 |
| 1093 | SEVERE STORMS AND FLOODING | DR | Flood | 1996-01-21 |
| 3105 | SEVERE SNOWFALL & WINTER STORM | EM | Snowstorm | 1993-03-16 |
| 737 | SEVERE STORMS, HIGH WINDS & TORNADOES | DR | Tornado | 1985-06-03 |
| 641 | SEVERE STORMS & FLOODING | DR | Flood | 1981-06-15 |
| 3026 | SNOWSTORMS | EM | Snowstorm | 1977-01-29 |
| 340 | TROPICAL STORM AGNES | DR | Flood | 1972-06-23 |
Storm Events in Pennsylvania
Statewide NOAA context only. PlainHazard does not currently attribute these state totals to Mercer County.
| Storm Type | Events | Fatalities | Injuries | Property Damage |
|---|---|---|---|---|
| Thunderstorm Wind | 9,976 | 18 | 114 | $115.5M |
| Flash Flood | 2,288 | 23 | 8 | $463.2M |
| Winter Weather | 1,670 | 23 | 268 | $566.0K |
| Hail | 1,400 | 0 | 0 | $2.6M |
| Winter Storm | 881 | 14 | 17 | $2.9M |
Source: NOAA Storm Events Database State-level aggregated data, 2015-2025
NFIP Flood Insurance Claims
Total Claims
120
Total Paid
$880.0K
Avg Per Claim
$7.3K
Source: FEMA National Flood Insurance Program (NFIP) OpenFEMA Claims Data
FEMA National Risk Index
Overall Risk
Relatively Low
Score: 77.7/100
Expected Annual Loss
Relatively Low
$34.1M/year
Social Vulnerability
Relatively Moderate
Community Resilience
Relatively High
Hazard Risk Breakdown
Riverine Flooding Relatively Moderate
Lightning Relatively High
Winter Weather Relatively Moderate
Hail Relatively Moderate
Strong Wind Relatively Moderate
Hurricane Relatively Low
Tornado Relatively Low
Earthquake Very Low
Landslide Very Low
Ice Storm Relatively Low
Wildfire Very Low
Heat Wave Very Low
Cold Wave 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: Riverine Flooding
Riverine Flooding is the model's measure of a watershed draining more water than its channel can carry. Unlike flash flooding it usually builds over days and is forecast in advance, which makes it the hazard where warning time most reliably converts into reduced harm.
Worth noting for Mercer County: the model and the federal record do NOT point at the same hazard. Riverine Flooding carries the highest modeled rating (Relatively Moderate), while the county's declaration history is led by Hurricane. 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: Harrison County, TX
Comparisons use published FEMA declaration fields plus the National Risk Index composite for Mercer County. Record similarity, not a safety rating.
Similar modeled NRI score
Mercer County: NRI composite 77.7 (Relatively Low).
Similar Major-disaster share
Mercer County: 8 of 13 of its declarations are Major.
Closest declaration profiles
Mercer County shows 13 FEMA declarations, led by Hurricane.
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.
Further reading for this county
Understanding disaster data
Mercer County's NFIP claims file (120 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 Mercer County?
The most common disaster type in Mercer County is Hurricane, with 3 declarations. Other disaster types include Flood (3), Biological (2), Severe Storm (2).
How does Mercer County's FEMA declaration record compare with the Pennsylvania average?
The typical Pennsylvania county has 18.6 FEMA declaration records; Mercer County has 13, or 30% fewer. Against the national county mean of 20.7, this county's total is 37% 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 8 major disaster declarations, representing 62% of all 13 disaster declarations.
How many flood insurance claims has Mercer County filed?
Mercer County has 120 National Flood Insurance Program (NFIP) claims totaling $880.0K in payments, with an average of $7.3K per claim.
What was the worst year for disasters in Mercer County?
The most active year for disaster declarations in Mercer County was 2004, with 2 declarations. The county has FEMA disaster data spanning 1972 to 2020.
What is the FEMA National Risk Index score for Mercer County?
According to the FEMA National Risk Index, Mercer County, Pennsylvania has an overall risk score of 77.7 out of 100 (Relatively Low). Social vulnerability here rates Relatively Moderate, while community resilience comes in at Relatively High. The Expected Annual Loss (EAL) score is Relatively Low, representing $34.1M 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 Riverine Flooding (risk rating: Relatively Moderate). Other significant hazards include Lightning (Relatively High) and Winter Weather (Relatively Moderate). FEMA's modeled event frequency puts riverine flooding here at an average of 2.5 times per year, drawn from 70 historical events on record. 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.
What this means for Mercer County
Against a Pennsylvania county mean of 19 declarations, Mercer County, PA records 13, or 30% fewer. PlainHazard classifies that historical total as high activity.
- Major Disaster is the largest group (8 of 13) in a declaration history that remains below its state benchmark; frequency here is not a forecast. Pennsylvania overview
- Nationally the county exceeds 17% of recorded county totals, but its own Pennsylvania 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.