Debris Flow and Flooding in Puerto Rico, September 27, 2025

Name: Debris Flow and Flooding in Puerto Rico, September 27, 2025
Start: 2025-09-27T14:35
End: 2025-09-27T17:30
Location: Puerto Rico

September 27, 2025 · NWS SJU · 3 events in 2 counties and zones

A band of moisture between Hurricane Humberto and the precursor of Hurricane Imelda moved over the islands. The combination of this moisture, light winds and diurnal heating resulted in showers and thunderstorms over the area, which triggered flooding and landslides in the vicinity of the San Juan metro area.

Where it happened

Every event with a place to put it. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

Open the live radar over this ground

The toll

Deaths: 0
Injuries: 0
Property damage: $2,000
Crop damage: None recorded
Events: 3

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS SJU wrote it up.

What forecasters said that day

The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS San Juan, PR wrote its last area forecast discussion before the first event at Sep 26, 2:56 PM AST, 23 hours 39 minutes earlier.

Area forecast discussion, Sep 26, 2:56 PM AST, 23 hours 39 minutes before

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The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

2 flood, 1 debris flow. Local standard time, as filed.

Flood, Guaynabo

When: September 27, 2:35 PM AST to 3:45 PM AST
Where: Guaynabo County, 7.16 mi NW of Guaynabo to 7.18 mi NW of Guaynabo
Cause: Heavy Rain
Property damage: $1,000
Reported by: Emergency Manager
Coordinates: 18.404, -66.106

Emergency managers reported flooding affecting the exit from Expreso Rafael Martinez Nadal toward Avenida Gonzalez Giusti/San Patricio Village, in front of the Dennis Restaurant near Plaza San Patricio in Guaynabo. The roadway has been closed and is currently impassable for all traffic.

Flood, San Juan

When: September 27, 3:10 PM AST to 3:45 PM AST
Where: San Juan County, 1.68 mi NE of San Juan to 1.73 mi NE of San Juan
Cause: Heavy Rain
Property damage: $400
Reported by: Public
Coordinates: 18.395, -66.030

Social media posts reported flooding along Avenida 65 de Infanteria in front of Concordia Shopping Center.

Debris Flow, Guaynabo

When: September 27, 3:30 PM AST to 5:30 PM AST
Where: Guaynabo County, 6.58 mi WNW of Guaynabo
Cause: Heavy Rain
Property damage: $400
Reported by: Emergency Manager
Coordinates: 18.381, -66.115

Emergency managers reported a small landslide at PR-833 near Urb. La Lomita in Sector Los Filtros in Barrio Frailes.

What these are

Flood: Flooding that develops more slowly than a flash flood: rivers leaving their banks, or water standing over land for an extended time.
Debris Flow: A fast-moving slurry of mud, rock and debris, usually on a slope soaked by heavy rain or stripped by a fire.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Puerto Rico in 2025 Every state in 2025 This day in weather history Warnings in Puerto Rico, September 2025

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 1294698, 1294699, 1294700.