836
Recorded events
21
Direct deaths
46
Direct injuries
$190.9M
Property damage
Flash Flood in San Bernardino County, California: 836 recorded events between 1996 and 2026. The strongest on record measured 0. That places the county #1 nationally and #1 statewide for this hazard.
Decade by decade
Flash Flood in San Bernardino County, California: events per decade
Reporting practice changed over time — early decades are undercounted, not calmer.
The busiest decade for flash flood in San Bernardino County is the 2010s, when 377 of the county's 836 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 San Bernardino County archive, flash flood makes up 50.9% of all recorded severe weather across 12 hazard types. Nationally the county sits at #1 for this hazard and #1 within California, putting it in the 100.0 percentile of all U.S. counties.
Seasonality
Events by month
Aug is the peak month for flash flood in San Bernardino County with 248 recorded events, while Apr 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 |
|---|---|---|---|---|---|
| Nov 8, 2022 | ONTARIO | 0 | 3 | 0 | $0 |
| Aug 26, 2003 | TWENTY NINE PALMS | 0 | 3 | 0 | $50K |
| Dec 26, 2003 | DEVORE | 0 | 2 | 5 | $1.0M |
| Jul 11, 1999 | FOREST FALLS | 0 | 1 | 5 | $6.0M |
| Feb 18, 2017 | VICTORVILLE | 0 | 1 | 2 | $30K |
| Sep 20, 2025 | LENWOOD | 0 | 1 | 1 | $10K |
| Jan 5, 2008 | CHINO ARPT | 0 | 1 | 1 | $10K |
| Feb 3, 2019 | JOSHUA TREE ARPT | 0 | 1 | 0 | $100K |
Most recent
Latest recorded events
| Date | Location | Magnitude | Damage |
|---|---|---|---|
| Feb 18, 2026 | KEENBROOK | — | $0 |
| Dec 24, 2025 | SCOTLAND | 0 | $0 |
| Dec 24, 2025 | DEVORE | 0 | $0 |
| Dec 24, 2025 | MT BALDY | 0 | $0 |
| Dec 24, 2025 | CAJON | 0 | $0 |
| Dec 24, 2025 | PINON HILLS | 0 | $0 |
| Nov 18, 2025 | KLINEFELTER | 0 | $20K |
| Nov 18, 2025 | JAVA | 0 | $1K |
| Nov 18, 2025 | ARROWHEAD JCT | 0 | $1K |
| Nov 16, 2025 | (NXP)MCAF TWENTYNINE | 0 | $5K |
Other hazards here
More from San Bernardino County
- Thunderstorm Wind 197
- Flood 160
- Heavy Rain 124
- Wildfire 90
- Hail 67
- Lightning 63
- Debris Flow 50
From the record
What the reports say
Written by National Weather Service staff at the time of the event · public domain
Ontario Fire department reported 6 person in the swiftwater channel in John Galvin park where the channel begins near I-10. Rainfall rates of 0.50 to 0.75 inches per hour had occurred from 7 am to 9 am in Ontario and Rancho Cucamonga. 3 persons were rescued. 3 more person were later found drowned in a retaining pond which was filled 15 to 20 feet high with storm runoff water. The bodies were not found until several days later due the water being too deep and low visibility. Multiple agencies were involved in the week long recovery efforts. The channel runs south past Ontario airport to where it reached the storage collection ponds on East Philadelphia Street. Search and rescue in Cucamonga Channel reported by CalOES and Ontario Fire Department. As many as 10 people experiencing homelessness were swept away as a surge of water occurred following 2 hours of heavy rain. Five people were immediately rescued, one person immediately reported deceased, with two additional bodies recovered (one of November 14, the other on November 16).
Severe flooding impacted much of Joshua Tree. Many roads were covered with water, mud, and rocks. Several homes were flooded, including one which was destroyed. A one year old boy was swept away in his back yard before being rescued. One man died when his vehicle was swept down a flooded wash.
Numerous roads and intersections were flooded in Yucca Valley and Joshua Tree, at least four homes were flooded, at least four vehicles were stranded, and at least six swift water rescues occurred. One man was killed when his vehicle was swept away by flood waters.
Quick answers
Frequently asked
How many flash flood events are on record in San Bernardino County, California?
836 flash flood events are recorded in San Bernardino County between 1996 and 2026, causing 21 direct deaths.
What is the strongest flash flood recorded in San Bernardino County?
The strongest flash flood on record in San Bernardino County measured 0.
Where does the flash flood data for San Bernardino 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 San Bernardino County, California.” Severe Weather History. severeweatherhistory.com/county/california/san-bernardino-county/flash-flood/ · Data: NOAA/NCEI, FEMA, U.S. Census — public domain.