68
Recorded events
0
Direct deaths
1
Direct injuries
$2.9M
Property damage
Flash Flood in Sussex County, Delaware: 68 recorded events between 1999 and 2025. The strongest on record measured 0. That places the county #357 nationally and #2 statewide for this hazard.
Decade by decade
Flash Flood in Sussex County, Delaware: events per decade
Reporting practice changed over time — early decades are undercounted, not calmer.
The busiest decade for flash flood in Sussex County is the 2010s, when 34 of the county's 68 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 Sussex County archive, flash flood makes up 8.0% of all recorded severe weather across 11 hazard types. Nationally the county sits at #357 for this hazard and #2 within Delaware, putting it in the 88.3 percentile of all U.S. counties.
Seasonality
Events by month
Jul is the peak month for flash flood in Sussex County with 26 recorded events, while Jan 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 |
|---|---|---|---|---|---|
| Sep 16, 1999 | COUNTYWIDE | 0 | 0 | 1 | $150K |
Most recent
Latest recorded events
| Date | Location | Magnitude | Damage |
|---|---|---|---|
| Jul 10, 2025 | BETHANY BEACH | 0 | $0 |
| Jul 10, 2025 | OCEAN VIEW | 0 | $0 |
| Jun 29, 2025 | BETHANY BEACH | 0 | $0 |
| Jun 29, 2025 | MILLVILLE | 0 | $0 |
| Jul 16, 2023 | GREENWOOD | 0 | $0 |
| Jul 16, 2023 | REDDEN | 0 | $0 |
| Jul 10, 2020 | FENWICK IS | 0 | $0 |
| Jul 10, 2020 | BELLTOWN | 0 | $0 |
| Jul 10, 2020 | OAK ORCHARD | 0 | $0 |
| Jul 10, 2020 | BETHANY BEACH | 0 | $0 |
Other hazards here
More from Sussex County
- Thunderstorm Wind 367
- Heavy Rain 192
- Lightning 80
- Hail 48
From the record
What the reports say
Written by National Weather Service staff at the time of the event · public domain
Thunderstorms with torrential downpours caused flash flooding in Eastern Sussex County. The hardest hit area was in and around Long Neck. Many roadways were flooded and closed. One road collapsed in Oak Orchard. In Oak Orchard, River Road was under water and the bulkhead of one home was damaged at the Riverwinds Development. Holly Lake Road was also closed Flooding was also reported along Beaver Dam Road and Delaware State Ropute 5. Along the coast, Delaware State Route 1 in Dewey Beach and Delaware State Route 26 leading into Bethany Beach were flooded. Event precipitation totals included 7.21 in Rehoboth Beach, 6.83 inches in Harbeson, 6.39 inches in Bethany Beach and 5.76 inches in Indian River Inlet.
Thunderstorms with torrential downpours caused roadway flash flooding in Rehoboth Beach. First Street was under two feet of water and at least one resort garage was flooded. Over two dozen vehicles were damaged. Event precipitation total was 7.21 inches.
Thunderstorms with very heavy rain led to flash flooding from Selbyville east in southern Sussex County. A few roads were closed and sections of Lighthouse and Sand Cove Roads collapsed. Event precipitation totals included 5.50 inches in Selbyville.
Quick answers
Frequently asked
How many flash flood events are on record in Sussex County, Delaware?
68 flash flood events are recorded in Sussex County between 1999 and 2025, causing 0 direct deaths.
What is the strongest flash flood recorded in Sussex County?
The strongest flash flood on record in Sussex County measured 0.
Where does the flash flood data for Sussex 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 Sussex County, Delaware.” Severe Weather History. severeweatherhistory.com/county/delaware/sussex-county/flash-flood/ · Data: NOAA/NCEI, FEMA, U.S. Census — public domain.