QUEZON CITY — A strengthening southwest monsoon is sweeping across the Philippines this Saturday, August 15, 2026, threatening flash floods and landslides in Metro Manila and much of Luzon while also pushing rain into parts of the Visayas. PAGASA issued its 24-hour public weather forecast at 4:00 AM Saturday, valid until 4:00 AM Sunday, August 16, 2026.
Residents across the northern and central island group should brace for a wet and potentially dangerous day, particularly those living in flood-prone low-lying communities and in mountainous areas susceptible to landslides. Even areas not directly under the heaviest rainfall bands could see brief but intense thunderstorms capable of causing localized flooding.
What Is Driving Today's Weather
The primary weather system behind today's conditions is the southwest monsoon, known locally as "habagat." According to PAGASA, it is currently affecting Luzon and the western section of Visayas.
The southwest monsoon is a seasonal shift in wind direction that brings moist, warm air from the southwest — typically from the South China Sea — into the western side of the Philippines from roughly June through September. When this moisture-laden air is pushed inland and meets the terrain of Luzon's mountain ranges, it is forced upward, cools rapidly, and produces heavy and often persistent rainfall. The result is the kind of cloudy, rain-drenched, and sometimes stormy weather that Filipinos in Metro Manila and surrounding provinces experience during the rainy season's peak months.
In Mindanao, PAGASA attributes today's rain not to the monsoon but to localized thunderstorms — isolated storm cells that develop due to daytime heating and atmospheric instability, producing short but intense bursts of rain, lightning, and gusty winds.
Region-by-Region Forecast
Luzon — Scattered Rains, Flash Flood and Landslide Risk
The heaviest impact today falls on a broad swath of Luzon. PAGASA forecasts cloudy skies with scattered rains and thunderstorms — with rain described as moderate to at times heavy — for the following areas:
- Metro Manila
- Ilocos Region (Ilocos Norte, Ilocos Sur, La Union, Pangasinan)
- Cordillera Administrative Region (Benguet, Mountain Province, Ifugao, Kalinga, Apayao, Abra)
- Cagayan Valley (Cagayan, Isabela, Nueva Vizcaya, Quirino, Batanes)
- Central Luzon (Aurora, Bataan, Bulacan, Nueva Ecija, Pampanga, Tarlac, Zambales)
- CALABARZON (Cavite, Laguna, Batangas, Rizal, Quezon)
- Occidental Mindoro
- Oriental Mindoro
For all of these areas, PAGASA explicitly warns of possible flash floods or landslides due to the moderate to heavy rains expected. Residents in mountainous terrain — particularly in the Cordillera — and those near rivers, esteros, and drainage channels in Metro Manila and CALABARZON must remain on alert.
The rest of Luzon — areas not listed above — can expect partly cloudy to cloudy skies with isolated rain showers or thunderstorms. Flash flood and landslide risks remain possible during any severe thunderstorm episodes in these areas as well.
Visayas — Isolated Showers, Thunderstorm Risk
The southwest monsoon's reach extends into the western portions of the Visayas, though with less intensity than in Luzon. PAGASA forecasts partly cloudy to cloudy skies with isolated rain showers or thunderstorms across the Visayas. The hazard warning is the same as for the rest of Luzon: possible flash floods or landslides during severe thunderstorms.
Residents in the Eastern Visayas and areas farther from the monsoon's direct path should still not dismiss the risk entirely — isolated thunderstorms can develop rapidly and deliver dangerous rainfall within a short span of time.
Mindanao — Localized Thunderstorms
Mindanao is not under the direct influence of the southwest monsoon today, but PAGASA warns that localized thunderstorms will still bring partly cloudy to cloudy skies with isolated rain showers or thunderstorms to the region. As in other parts of the country, these storms carry the risk of flash floods or landslides during severe episodes.
Communities in mountainous Mindanao provinces — including Bukidnon, Davao de Oro, Agusan del Sur, and similar highland areas — should be particularly alert to rapidly rising water levels in rivers and streams during and after heavy downpours.
Sea Conditions and Coastal Warnings
The southwest monsoon is also churning the seas around the Philippines, and PAGASA is warning fisherfolk and maritime operators to exercise caution.
The northern and western sections of Luzon will experience moderate to strong winds blowing from the southwest, with moderate to rough coastal waters — meaning wave heights of 1.5 to 2.8 meters. These are dangerous conditions for small fishing bancas and non-motorized watercraft. Even larger vessels should proceed with caution.
The rest of the country will see light to moderate winds from the south to southwest, with slight to moderate coastal waters and wave heights of 0.6 to 1.8 meters. While less severe, these conditions can still pose challenges for small boats, particularly during gusts associated with passing thunderstorms.
Decoding the Warnings: What the Hazards Actually Mean
PAGASA has flagged possible flash floods or landslides as the key hazards for today across Luzon, Visayas, and Mindanao. In plain terms, this means:
Flash floods can occur with little to no warning, especially in low-lying areas, near rivers, and in urban zones with poor drainage. Even a few hours of moderate to heavy rain can cause streets and underpasses to flood rapidly.
Landslides are a risk in mountainous and hilly provinces — including the Cordillera, parts of Cagayan Valley, and highland Mindanao — when rain saturates already-soft soil. Residents near slopes, cliffs, and hillsides should be prepared to evacuate quickly if authorities call for it.
If you want to better understand how PAGASA classifies weather hazards and what each warning level requires you to do, read our guide on how to read PAGASA's weather warnings.
No tropical cyclone wind signals are in effect as of this forecast.
What Today's Weather Means for You
Commuters
Metro Manila and surrounding provinces in CALABARZON and Central Luzon are in for a difficult commute today. Expect traffic to worsen significantly during rain bursts, particularly in flood-prone roads and underpasses. Leave earlier than usual, allow extra travel time, and check your route before departing. Avoid driving through flooded streets — even shallow-looking floodwater can hide deep potholes or conceal fast-moving current.
Fisherfolk and Small-Boat Operators
PAGASA's sea condition data is a clear caution for those planning to go out on the water. In northern and western Luzon coastal waters, waves of up to 2.8 meters make conditions dangerous for small vessels. Fisherfolk in Ilocos Norte, Ilocos Sur, Pangasinan, and the western Luzon seaboard are strongly advised to stay ashore today. Even in the rest of the country where waves are milder, sudden thunderstorms can quickly escalate sea conditions.
Farmers
The heavy rains across Luzon could cause waterlogging in low-lying agricultural fields. Rice farmers in Central Luzon, Cagayan Valley, and CALABARZON — who are in the early stages of the wet season crop cycle — should check their drainage systems and secure any farm structures that may be vulnerable to strong winds accompanying thunderstorms.
Students, Parents, and Schools
With scattered to isolated thunderstorms forecast throughout the day, the risk of sudden heavy rain is real even in areas that may start the morning dry. Parents sending children to school should ensure they have rain gear, and should monitor local government and school announcements for any suspension of classes — particularly in Metro Manila, Cordillera, and other high-risk areas where flash flooding is a concern.
Outdoor Workers
Construction workers, utility workers, and others who work outdoors across Luzon should treat today as a high-caution day. Avoid working near slopes or excavation sites during heavy rain. Thunderstorms also bring lightning risk — cease outdoor work and seek shelter indoors at the first signs of an approaching storm.
Temperature Outlook
PAGASA's weather station at Science Garden in Diliman, Quezon City recorded a maximum temperature of 26.5°C (at 11:00 AM) and a minimum of 25.1°C (at 12:00 PM) for the 24-hour period ending 8:00 PM yesterday, August 14, 2026. Relative humidity was high, reaching a maximum of 98% and a minimum of 88% — consistent with the thick monsoon cloud cover and persistent moisture in the air.
These readings suggest that while temperatures themselves are not extreme, the high humidity will make the air feel heavy and sticky in between rain showers. The overcast skies brought by the habagat are keeping maximum temperatures from climbing higher.
Sunrise, Sunset, and Tides for Metro Manila
For those planning activities around daylight today, Saturday, August 15, 2026: sunrise in Metro Manila is at 5:42 AM and sunset at 6:19 PM. Moonrise is at 7:48 AM and moonset at 8:09 PM, with the moon at just 9% illumination — a thin crescent that offers little light after dark.
Manila Bay tidal predictions (courtesy of NAMRIA via PAGASA) show a high tide of 1.33 meters at 11:42 AM and a low of 0.23 meters at 7:08 PM. Coastal communities around Manila Bay should factor these tidal conditions into their flood risk assessments, especially if heavy rains coincide with high tide.
Bottom Line
The southwest monsoon is making much of Luzon — including Metro Manila — a high-risk zone for flash floods and landslides today, August 15, 2026. If you live or work in a flood-prone area, near a river, or close to a hillside anywhere in Luzon, stay alert, keep your emergency kit accessible, and be ready to move to higher ground quickly if conditions worsen. Do not wait for the water to rise before you act.
Monitor official PAGASA updates at pagasa.dost.gov.ph.