241
Recorded events
1
Direct deaths
4
Direct injuries
$3.4M
Property damage
Flash Flood in Montgomery County, Maryland: 241 recorded events between 1996 and 2025. The strongest on record measured 0. That places the county #23 nationally and #2 statewide for this hazard.
Decade by decade
Flash Flood in Montgomery County, Maryland: events per decade
Reporting practice changed over time — early decades are undercounted, not calmer.
The busiest decade for flash flood in Montgomery County is the 2010s, when 111 of the county's 241 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 Montgomery County archive, flash flood makes up 15.1% of all recorded severe weather across 8 hazard types. Nationally the county sits at #23 for this hazard and #2 within Maryland, putting it in the 99.3 percentile of all U.S. counties.
Seasonality
Events by month
Jul is the peak month for flash flood in Montgomery County with 93 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 1, 2021 | AUTREY PARK | 0 | 1 | 3 | $1.0M |
| Jan 19, 1996 | ALL | 0 | 0 | 1 | $0 |
Most recent
Latest recorded events
| Date | Location | Magnitude | Damage |
|---|---|---|---|
| Jul 31, 2025 | PARKWOOD | 0 | $0 |
| Jul 31, 2025 | CARDEROCK SPGS | 0 | $0 |
| Jul 31, 2025 | CARDEROCK SPGS | 0 | $0 |
| Jul 31, 2025 | POTOMAC | 0 | $0 |
| Jul 20, 2025 | GEORGETOWN JCT | 0 | $0 |
| Jul 19, 2025 | CARDEROCK SPGS | 0 | $0 |
| Jul 19, 2025 | KEMP MILL | 0 | $0 |
| Jul 19, 2025 | GEORGETOWN JCT | 0 | $0 |
| Jul 19, 2025 | KEMP MILL | 0 | $0 |
| Jul 19, 2025 | CARDEROCK SPGS | 0 | $0 |
Other hazards here
More from Montgomery County
- Thunderstorm Wind 880
- Hail 191
- Flood 186
- Lightning 42
From the record
What the reports say
Written by National Weather Service staff at the time of the event · public domain
Floodwaters rushed into the Rock Creek Woods Apartments shortly before 3 AM EST according to Montgomery County Police and Fire Officials. The water rose almost to the ceilings in some cases. A 19 year old male was deceased due to the floodwaters. ||Three people were hospitalized due to injuries that were not life threatening, and one firefighter suffered minor injuries.
Numerous county roads closed in the southeastern part of the county near the Washington DC line. There were 147 reports of flooded basements. Twenty five swift water rescues occurred. In Chevy Chase, firefighters used boats to rescue 30 people trapped inside a recreational center. The Chevy Chase Village area off Wisconsin Ave had knee-deep water. There were 45 individual rescues Meadowbrook Park. Water reached the window of a stalled car on a bridge over great Seneca Creek in upper Montgomery County. A road was washed out at US 29 at New Hampshire Avenue in Silver Spring. Three swift water rescues occurred in Rock Creek Park. About 26 vehicles were recovered after water reached their windows. A driveway collapsed on Colesville Road in Silver Spring. Boats were used to rescue 30 men at a field house in Candy Cane City Park. Colesville received 12.5 inches during the event. Significant damage was reported in Northwest Branch Park when the river topped its banks by approximately 100 yards.
Numerous Road closures were reported countywide. In Derwood, a bridge was damaged over a creek between Bowie Mill Road and Redland Middle School. Asphalt was torn up and debris scattered about. Nearly 2000 people in Montgomery County were evacuated when engineers on site determined that the Lake Needwood Dam may fail due to substantially above normal water levels on June 28. Fortunately, this did not occur.
Quick answers
Frequently asked
How many flash flood events are on record in Montgomery County, Maryland?
241 flash flood events are recorded in Montgomery County between 1996 and 2025, causing 1 direct deaths.
What is the strongest flash flood recorded in Montgomery County?
The strongest flash flood on record in Montgomery County measured 0.
Where does the flash flood data for Montgomery 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 Montgomery County, Maryland.” Severe Weather History. severeweatherhistory.com/county/maryland/montgomery-county/flash-flood/ · Data: NOAA/NCEI, FEMA, U.S. Census — public domain.