203
Recorded events
1
Direct deaths
2
Direct injuries
$4.5M
Property damage
Flash Flood in San Juan Municipio, Puerto Rico: 203 recorded events between 1997 and 2025. The strongest on record measured 0. That places the county #39 nationally and #1 statewide for this hazard.
Decade by decade
Flash Flood in San Juan Municipio, Puerto Rico: events per decade
Reporting practice changed over time — early decades are undercounted, not calmer.
The busiest decade for flash flood in San Juan Municipio is the 2020s, when 101 of the county's 203 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 Juan Municipio archive, flash flood makes up 40.2% of all recorded severe weather across 13 hazard types. Nationally the county sits at #39 for this hazard and #1 within Puerto Rico, putting it in the 98.8 percentile of all U.S. counties.
Seasonality
Events by month
May is the peak month for flash flood in San Juan Municipio with 36 recorded events, while Mar 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 |
|---|---|---|---|---|---|
| Apr 28, 2025 | SAN JUAN | 0 | 1 | 0 | $25K |
| Aug 1, 2023 | SAN JUAN | 0 | 0 | 2 | $4K |
Most recent
Latest recorded events
| Date | Location | Magnitude | Damage |
|---|---|---|---|
| Dec 25, 2025 | SAN JUAN | 0 | $1K |
| Dec 25, 2025 | SAN JUAN | 0 | $1K |
| Sep 22, 2025 | SAN JUAN | 0 | $0 |
| Apr 30, 2025 | SAN JUAN | 0 | $600 |
| Apr 28, 2025 | SAN JUAN | 0 | $10K |
| Apr 28, 2025 | SAN JUAN | 0 | $5K |
| Apr 28, 2025 | SAN JUAN | 0 | $5K |
| Apr 28, 2025 | SAN JUAN | 0 | $25K |
| Nov 5, 2024 | SAN JUAN | 0 | $400 |
| Oct 31, 2024 | SAN JUAN | 0 | $1K |
Other hazards here
More from San Juan Municipio
- Flood 227
From the record
What the reports say
Written by National Weather Service staff at the time of the event · public domain
The 911 Call Center reported that individuals were stranded in a Kia vehicle due to flash flooding from nearby streams along Camino Los Navarro in Barrio Quebrada Arenas, near Road PR-1 in San Juan. The floodwaters inundated the roadway, creating hazardous conditions and prompting a rescue response.
High rainfall runoff along the northern De Diego Avenue in Puerto Nuevo combined with the Puerto Nuevo river overflow, flooding the northern end of De Diego Avenue, under the PR-22 bridge underpass. An automobile and its two occupants were stranded.
An NWS employee reported that Avenida Jesus T. Pinero, near Farmacia Caridad and the Total Energy gas station in the direction of Carolina, was affected by flooding. Around three inches of rain had fallen in the past two hours.
Quick answers
Frequently asked
How many flash flood events are on record in San Juan Municipio, Puerto Rico?
203 flash flood events are recorded in San Juan Municipio between 1997 and 2025, causing 1 direct deaths.
What is the strongest flash flood recorded in San Juan Municipio?
The strongest flash flood on record in San Juan Municipio measured 0.
Where does the flash flood data for San Juan Municipio 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 Juan Municipio, Puerto Rico.” Severe Weather History. severeweatherhistory.com/county/puerto-rico/san-juan-municipio/flash-flood/ · Data: NOAA/NCEI, FEMA, U.S. Census — public domain.