82
Recorded events
0
Direct deaths
0
Direct injuries
$767K
Property damage
Flash Flood in Mercer County, Pennsylvania: 82 recorded events between 1996 and 2025. The strongest on record measured 0. That places the county #258 nationally and #21 statewide for this hazard.
Decade by decade
Flash Flood in Mercer County, Pennsylvania: events per decade
Reporting practice changed over time — early decades are undercounted, not calmer.
The busiest decade for flash flood in Mercer County is the 2000s, when 33 of the county's 82 recorded events were logged. Comparing decades is useful for spotting active periods, but the earliest years are thin because systematic reporting for this hazard began later.
Within the Mercer County archive, flash flood makes up 10.1% of all recorded severe weather across 7 hazard types. Nationally the county sits at #258 for this hazard and #21 within Pennsylvania, putting it in the 91.5 percentile of all U.S. counties.
Seasonality
Events by month
Jul is the peak month for flash flood in Mercer County with 30 recorded events, while Feb is the quietest. Seasonality here is a property of the archive as much as the climate: reports cluster where population and spotter networks are densest.
Most recent
Latest recorded events
| Date | Location | Magnitude | Damage |
|---|---|---|---|
| Jul 16, 2025 | CENTERTOWN | 0 | $0 |
| Jul 21, 2023 | HENLEIN | 0 | $5K |
| Sep 5, 2022 | MILLBROOK | 0 | $0 |
| Aug 14, 2021 | HADLEY | 0 | $0 |
| Jul 17, 2021 | FREDONIA | 0 | $10K |
| Jul 16, 2021 | NEW HAMBURG | 0 | $10K |
| Jul 16, 2021 | NEW HAMBURG | 0 | $50K |
| Aug 18, 2019 | JAMESTOWN | 0 | $0 |
| Aug 18, 2019 | JAMESTOWN | 0 | $0 |
| Aug 5, 2019 | CHARLESTON | 0 | $0 |
Other hazards here
More from Mercer County
- Thunderstorm Wind 519
- Hail 160
From the record
What the reports say
Written by National Weather Service staff at the time of the event · public domain
Heavy thunderstorm rains of over 3 inches in only a few hours resulted in numerous reports of flooding across the downtown Sharon area. Several businesses reported flood damage. A 50-by-60 foot section of the roof of one business collapsed due to the weight of the rain water. Many homes reported flooded basements, while one home had its basement wall collapsed by the rushing waters. Several roadways across the Sharon area were impassible due to flooding.
In Sharon, basement and roadway flooding was reported with a few secondary roadways near Sharon partially washed away by the flooding. Minor roadway flooding was reported in the Greenville and Sugar Grove areas. Flooding was also reported along U.S. Route 62 from Charleston to Hermitage. Several roadways in the New Lebanon area were reported under water.
Heavy rains produced minor flooding along Lawongo Run, Mill Run, and several smaller creeks between Fredonia and Transfer. Spotters also reported minor flooding along other creeks across the county, which forced the temporary closure of several roads.
Quick answers
Frequently asked
How many flash flood events are on record in Mercer County, Pennsylvania?
82 flash flood events are recorded in Mercer County between 1996 and 2025, causing 0 direct deaths.
What is the strongest flash flood recorded in Mercer County?
The strongest flash flood on record in Mercer County measured 0.
Where does the flash flood data for Mercer County come from?
All events come from the NOAA/NCEI Storm Events Database, the federal public-domain archive of severe weather reports. Dates are UTC, damage is as reported and not inflation-adjusted, and the most recent entries may still be revised.
Cite this page
“Flash Flood in Mercer County, Pennsylvania.” Severe Weather History. severeweatherhistory.com/county/pennsylvania/mercer-county/flash-flood/ · Data: NOAA/NCEI, FEMA, U.S. Census — public domain.