156
Recorded events
4
Direct deaths
5
Direct injuries
$27.9M
Property damage
Flash Flood in New Castle County, Delaware: 156 recorded events between 1996 and 2025. The strongest on record measured 0. That places the county #65 nationally and #1 statewide for this hazard.
Decade by decade
Flash Flood in New Castle County, Delaware: events per decade
Reporting practice changed over time — early decades are undercounted, not calmer.
The busiest decade for flash flood in New Castle County is the 2010s, when 48 of the county's 156 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 New Castle County archive, flash flood makes up 17.9% of all recorded severe weather across 9 hazard types. Nationally the county sits at #65 for this hazard and #1 within Delaware, putting it in the 97.9 percentile of all U.S. counties.
Seasonality
Events by month
Aug is the peak month for flash flood in New Castle County with 39 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 |
|---|---|---|---|---|---|
| Sep 16, 1999 | COUNTYWIDE | 0 | 2 | 1 | $8.0M |
| Aug 28, 2011 | MILFORD XRDS | 0 | 2 | 0 | $0 |
| Jul 14, 2010 | HOLLY OAK | 0 | 0 | 1 | $50K |
| Jul 12, 2004 | COUNTYWIDE | 0 | 0 | 1 | $0 |
| Sep 15, 2003 | NORTH PORTION | 0 | 0 | 1 | $16.1M |
| Jan 18, 1999 | NORTH PORTION | 0 | 0 | 1 | $0 |
Most recent
Latest recorded events
| Date | Location | Magnitude | Damage |
|---|---|---|---|
| Jul 31, 2025 | EDGE MOOR | 0 | $10K |
| Jul 31, 2025 | ELSMERE JCT | 0 | $0 |
| Jul 31, 2025 | MONROE PARK | 0 | $10K |
| Jul 31, 2025 | CARPENTER | 0 | $0 |
| Jul 10, 2025 | MT CUBA | 0 | $0 |
| Jul 10, 2025 | YORKLYN | 0 | $0 |
| Jul 10, 2025 | DUROSS HGTS | 0 | $0 |
| Jul 9, 2025 | BELVIDERE | 0 | $50K |
| Jul 9, 2025 | MT CUBA | 0 | $0 |
| Jul 9, 2025 | TALLEYVILLE | 0 | $0 |
Other hazards here
More from New Castle County
- Thunderstorm Wind 444
- Hail 73
- Flood 70
- Lightning 49
From the record
What the reports say
Written by National Weather Service staff at the time of the event · public domain
Widespread flash flooding occurred in New Castle County with many road closures. Several rivers and creeks in the county overflowed their banks, including the Christina River, the Red Clay Creek and the White Clay Creek. More than 200 residences were affected by the flooding.
Thunderstorms with torrential downpours caused flash flooding in and around Wilmington. The flooding forced the safe evacuation of nearly three dozen infant and toddlers at an Elsmere day care center on Kirkwood Highway. The highway had up to four feet of water on it and was closed between Maple Avenue and Saunders Road. A bakery was also damaged by the flooding as were about 14 vehicles at the Veterans Affair Medical Center. In Wilmington, fire fighters made three water rescues. A man in his 50s was injured trying to rescue a woman stuck in flood waters. Three major roadways were closed including Governor Printz Boulevard. Elsewhere flooding along the Noneguch Creek near New Castle flooded Airport Road and several vehicles were stuck in high water in New Castle. The two day Doppler Radar storm total estimates reached 6 to 8 inches in the area.
Thunderstorms with torrential downpours caused small stream and considerable urban and poor drainage flash flooding in and around Wilmington. A couple of major roadways were flooded and closed including Old Airport Road and Lancaster Avenue. A woman's vehicle stalled while trying to pass through a parking lot lake in Edgemoor off the Governor Prinz Boulevard. Storm totals included 2.78 inches in Wilmington and 2.45 inches at the New Castle County Airport.
Quick answers
Frequently asked
How many flash flood events are on record in New Castle County, Delaware?
156 flash flood events are recorded in New Castle County between 1996 and 2025, causing 4 direct deaths.
What is the strongest flash flood recorded in New Castle County?
The strongest flash flood on record in New Castle County measured 0.
Where does the flash flood data for New Castle 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 New Castle County, Delaware.” Severe Weather History. severeweatherhistory.com/county/delaware/new-castle-county/flash-flood/ · Data: NOAA/NCEI, FEMA, U.S. Census — public domain.