MANILA, September 13, 2026 — Filipinos across the country should prepare for a wet and humid Sunday, as the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) forecasts partly cloudy to cloudy skies with isolated rainshowers and thunderstorms nationwide. The state weather bureau issued this outlook in its 4:00 AM bulletin on Sunday, September 13, 2026, valid until 4:00 AM on Monday, September 14.
While no tropical cyclone is active in the Philippine Area of Responsibility, PAGASA warns that the risk of flash floods and landslides remains real — particularly wherever thunderstorms become severe. Residents in vulnerable communities are advised to stay alert and avoid unnecessary exposure to adverse weather throughout the day.
What Is Driving Today's Weather
PAGASA identifies easterlies as the weather system directly affecting Extreme Northern Luzon — specifically the Batanes group of islands and the Babuyan Islands. Easterlies are winds that blow from the east across the Pacific Ocean toward the Philippine landmass. When these moisture-laden winds make landfall over elevated terrain or interact with local atmospheric conditions, they can trigger rainshowers and, under the right circumstances, intense thunderstorms.
For the rest of the country — from mainland Luzon through the Visayas and down to Mindanao — localized thunderstorms are cited as the primary cause of expected rainfall. These are weather disturbances that develop due to daytime heating and atmospheric instability rather than a large-scale weather system. They tend to be short-lived but can be intense, producing heavy downpours, strong winds, and lightning in a concentrated area within a short period.
Region-by-Region Forecast
Extreme Northern Luzon — Batanes and Babuyan Islands
Residents and visitors in the Batanes group of islands and the Babuyan Islands should expect partly cloudy to cloudy skies with isolated rainshowers or thunderstorms on Sunday. According to PAGASA, the easterlies are the direct driver of these conditions. The agency warns that severe thunderstorms in these areas could trigger flash floods or landslides, posing a hazard to residents in low-lying zones and hillside communities. Winds in this area are light to moderate, blowing from the northeast to east, with coastal waters described as slight to moderate in wave height.
The Rest of Luzon — Metro Manila and Beyond
Metro Manila and the remainder of Luzon can expect partly cloudy to cloudy skies with isolated rainshowers or thunderstorms driven by localized thunderstorm activity. As with the far north, PAGASA flags the possibility of flash floods or landslides if any thunderstorm intensifies significantly. Commuters and outdoor workers across the National Capital Region and nearby provinces should keep an eye on the sky, as these localized storms can develop quickly and with little warning.
Winds across this area are light to moderate, blowing from the northeast to east. Coastal waters around Luzon are in slight to moderate condition.
Visayas
The Visayas — including Eastern, Western, and Central Visayas — fall under the same forecast umbrella as the rest of the country. Partly cloudy to cloudy skies are expected, with isolated rainshowers or thunderstorms driven by localized activity. The same caution about flash floods and landslides during severe thunderstorms applies to this region. Winds are light to moderate from the northeast to east, and coastal waters are slight to moderate.
Mindanao
Across Mindanao — from the Davao Region and SOCCSKSARGEN down through the Zamboanga Peninsula, Northern Mindanao, Caraga, and the Bangsamoro Autonomous Region — conditions mirror the rest of the country: partly cloudy to cloudy with isolated rainshowers or thunderstorms from localized activity. PAGASA's flash flood and landslide warnings remain applicable here, particularly in mountainous provinces and areas near river systems. Winds are light to moderate from the northeast to east, with slight to moderate coastal waters.
Decoding the Warnings: What PAGASA Is Actually Telling You
PAGASA's bulletin does not issue a tropical cyclone wind signal for today's forecast — there is no active storm in Philippine territory as of this writing. However, the agency does flag a specific hazard: the possibility of flash floods or landslides during severe thunderstorms. This is not a casual advisory. It means that if a thunderstorm in your area intensifies — producing prolonged heavy rain over a short period — low-lying communities could experience sudden flooding, and slopes in mountainous areas could become unstable.
This type of hazard warning does not require a typhoon. Localized thunderstorms, precisely because they concentrate rainfall in a small area quickly, can generate enough water volume to overwhelm drainage systems and saturate soil on hillsides. Residents in known flood-prone barangays or near slopes should take this seriously and not wait for floodwaters to rise before acting.
For a full plain-language guide to what each warning level means and how to respond, see how to read PAGASA's weather warnings.
What Today's Weather Means for You
Commuters
Metro Manila and urban centers across Luzon, Visayas, and Mindanao should prepare for the possibility of sudden, localized downpours at any point during the day. These isolated thunderstorms can strike quickly and cause street flooding that disrupts traffic flow. Bring a rain jacket or umbrella regardless of whether the morning looks clear, and check local traffic advisories before heading out. If you see skies darkening rapidly, seek shelter before heavy rain begins.
Fisherfolk and Small-Boat Operators
Coastal waters nationwide are described by PAGASA as slight to moderate in wave height, with light to moderate winds blowing from the northeast to east. While these conditions are not classified as dangerous for larger vessels, small-boat operators and fisherfolk — particularly those near the Batanes and Babuyan Islands in the far north, where easterlies are active — should exercise extra caution. Thunderstorms can develop quickly over open water and create conditions that are hazardous for smaller watercraft. Always check the latest PAGASA marine forecast before setting out.
Farmers
Isolated thunderstorms can bring brief but intense rainfall that benefits some crops while damaging others — particularly those vulnerable to waterlogging or wind. Farmers in areas prone to flash floods should secure equipment and harvest what is ready if heavy rain is anticipated. The localized nature of these storms means conditions can vary significantly from one municipality to the next, so local observation remains essential.
Students, Parents, and Schools
With isolated thunderstorms possible throughout the day, parents sending children to school or extracurricular activities should monitor weather developments closely. Lightning poses a serious risk during thunderstorms — ensure children are indoors during any heavy rain. School administrators and local government units should have contingency plans ready in case storms intensify during school hours.
Outdoor Workers and Construction Teams
Workers on construction sites, in agriculture, or in any outdoor setting should be alert to changing weather throughout the day. If a thunderstorm approaches, pause outdoor work immediately — lightning strikes, falling debris, and flash flooding are real hazards associated with severe thunderstorms. Supervisors should ensure workers know the procedure for seeking shelter quickly.
Temperature and Humidity Outlook
Based on PAGASA's recorded extremes at the Quezon City weather station for the 24-hour period ending 6:00 PM on Saturday, September 12, the maximum temperature reached 33.5°C at 2:00 PM, while the minimum dipped to 24.5°C at 6:00 AM. Relative humidity was high throughout the period, reaching 88% at 6:00 AM and a minimum of 89% at 2:00 PM — meaning the air carried nearly as much moisture as it could hold even at its driest point of the day.
This combination of heat and high humidity can make the "feels like" temperature considerably higher than the thermometer reading, increasing the risk of heat exhaustion for those working or spending extended time outdoors during non-rainy periods. Drink water regularly, avoid prolonged sun exposure during midday hours, and seek shade or air-conditioned spaces when possible.
Tidal and Astronomical Information for Metro Manila
For reference, PAGASA's tidal predictions for Metro Manila on Sunday, September 13, show a low tide of 0.3 meters at 5:45 AM and a high tide of 0.82 meters at 3:38 PM. The moon is at 6% illumination — nearly a new moon — rising and setting according to PAGASA's published schedule. Tidal information is relevant for coastal communities monitoring storm surge risk during thunderstorms, though no surge advisory has been issued for today.
Bottom Line
Bottom line: There is no typhoon today, but isolated thunderstorms can strike fast and hard anywhere in the Philippines on Sunday, September 13. The single most important thing you can do is stay alert to changing skies in your area, bring rain protection wherever you go, and — if you live in a low-lying or hillside community — know your evacuation route in case flash flooding or landslides develop during a severe storm.
Monitor official PAGASA updates at pagasa.dost.gov.ph