56
Recorded events
0
Direct deaths
1
Direct injuries
$7.2M
Property damage
Flash Flood in Warren County, New Jersey: 56 recorded events between 1996 and 2025. The strongest on record measured 0. That places the county #519 nationally and #16 statewide for this hazard.
Decade by decade
Flash Flood in Warren County, New Jersey: events per decade
Reporting practice changed over time — early decades are undercounted, not calmer.
The busiest decade for flash flood in Warren County is the 2000s, when 18 of the county's 56 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 Warren County archive, flash flood makes up 12.0% of all recorded severe weather across 8 hazard types. Nationally the county sits at #519 for this hazard and #16 within New Jersey, putting it in the 83.0 percentile of all U.S. counties.
Seasonality
Events by month
Jul is the peak month for flash flood in Warren County with 15 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.
Significant events
Deadliest on record
| Date | Location | Scale | Deaths | Injuries | Damage |
|---|---|---|---|---|---|
| Aug 4, 2003 | NORTHWEST PORTION | 0 | 0 | 1 | $0 |
Most recent
Latest recorded events
| Date | Location | Magnitude | Damage |
|---|---|---|---|
| Jul 14, 2025 | ALPHA | 0 | $0 |
| Jul 3, 2025 | PHILLIPSBURG | 0 | $0 |
| Aug 18, 2024 | BLAIRSTOWN | 0 | $0 |
| Jul 16, 2023 | MANUNKA CHUNK | 0 | $0 |
| Jul 16, 2023 | MARTINS CREEK STATION | 0 | $0 |
| Jul 16, 2023 | DELAWARE | 0 | $0 |
| Jul 15, 2023 | LOWER HARMONY | 0 | $0 |
| Jul 15, 2023 | HAZEN | 0 | $0 |
| Jun 26, 2023 | BLOOMSBURY | 0 | $0 |
| Jun 26, 2023 | BROADWAY | 0 | $0 |
Other hazards here
More from Warren County
From the record
What the reports say
Written by National Weather Service staff at the time of the event · public domain
Thunderstorms with heavy downpours caused flash flooding along smaller streams and roadways in eastern Warren County mainly in Allamuchy, Franklin, Hackettstown, Independence and Mansfield Townships. In Franklin Township, residents of the Pohatcong Creek Mobile Home Adult Community were rescued by boat after that creek flooded. Schools were closed in Mansfield Township. Homes along State Route 57 were flooded. In Hackettstown, the Trout Brook flooded U.S. Route 46 and Stiger Street. A half dozen roads were closed in the town and at least three cars were damaged. Some basements were also flooded. Both the Pequest and Musconetcong Rivers flooded again. The flooding rains also damaged the apple, corn and sod crops. Event precipitation totals included 4.91 inches in Blairstown, 4.77 inches in Hackettstown, 4.47 inches in Allamuchy and 4.21 inches in Mansfield.
Thunderstorms with heavy rain caused small stream and poor drainage flash flooding in northwest Warren County in Knowlton, Pahaquarry, and Hardwick Townships and affected the Worthington State Forest area the hardest. Doppler Radar storm total estimates nearly reached 5 inches in the northwest part of the county. Event precipitation totals included 2.90 inches in Hope and 1.94 inches in Pequest.
Runoff from the heavy rain caused flooding of streams and roadways in southern Warren County. A road was closed in Pohatcong Township because of the flooding. Event precipitation totals included 2.29 inches in Greenwich Township and 1.85 inches at the Belvidere Bridge.
Quick answers
Frequently asked
How many flash flood events are on record in Warren County, New Jersey?
56 flash flood events are recorded in Warren County between 1996 and 2025, causing 0 direct deaths.
What is the strongest flash flood recorded in Warren County?
The strongest flash flood on record in Warren County measured 0.
Where does the flash flood data for Warren 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 Warren County, New Jersey.” Severe Weather History. severeweatherhistory.com/county/new-jersey/warren-county/flash-flood/ · Data: NOAA/NCEI, FEMA, U.S. Census — public domain.