MINDANAO — Much of Mindanao will experience partly cloudy to cloudy skies with isolated rainshowers and thunderstorms over the next 24 hours, with the Zamboanga Peninsula particularly affected by the Southwest Monsoon, according to the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) Mindanao Regional Services Division.
The regional weather forecast, issued at 5:00 a.m. on September 19, 2026, is valid until 5:00 a.m. on September 20.
PAGASA said the Zamboanga Peninsula will experience partly cloudy skies that may become cloudy at times, accompanied by isolated rainshowers or thunderstorms due to the prevailing Southwest Monsoon.
The rest of Mindanao is likewise expected to experience partly cloudy to cloudy conditions, with isolated rainshowers or localized thunderstorms possible during the forecast period.
Risk of flash floods and landslides
While the forecast does not indicate continuous widespread rainfall across Mindanao, PAGASA warned that severe thunderstorms could still produce sudden heavy rain, creating the possibility of flash floods and landslides.
Residents, motorists and communities located near rivers, waterways, steep slopes and other flood- or landslide-prone areas are urged to remain alert, particularly when thunderstorms develop.
Thunderstorms may also bring sudden gusty winds and reduced visibility, potentially affecting road travel and outdoor activities.
Southwest winds, moderate seas
Winds across the region are forecast to be light to moderate from the southwest.
Coastal waters are expected to remain slight to moderate, generally ranging from 0.6 to 2.1 meters, although conditions may become more hazardous locally during thunderstorms.
Fishing communities, small boat operators and other coastal residents should continue monitoring local weather conditions before heading to sea, particularly when thunderstorms are observed nearby.
Zamboanga Peninsula
Across Zamboanga City, Zamboanga del Norte, Zamboanga del Sur, Zamboanga Sibugay and Isabela City, partly cloudy to occasionally cloudy skies are expected, with rainshowers or thunderstorms possible.
Temperatures are expected to range from about 24°C to 34°C across the peninsula during the forecast period, depending on the locality and time of day.
Northern Mindanao
The provinces of Bukidnon, Camiguin, Lanao del Norte, Misamis Occidental and Misamis Oriental are also expected to experience partly cloudy to cloudy skies with isolated rainshowers or thunderstorms.
Forecast temperatures range from around 20°C to 33°C, with Bukidnon and Lanao del Norte among the cooler areas.
Davao Region
Similar conditions are forecast across Metro Davao, Davao del Norte, Davao del Sur, Davao Oriental, Davao de Oro and Davao Occidental.
Rainshowers or thunderstorms may develop intermittently, while temperatures are generally expected to reach the upper 20s to low 30s Celsius. Davao de Oro could reach around 33°C, while other parts of the region may reach approximately 31–33°C.
SOCCSKSARGEN
North Cotabato, South Cotabato, Sultan Kudarat and Sarangani will likewise experience partly cloudy to cloudy skies with isolated rainshowers or thunderstorms.
Temperatures are forecast to range from approximately 21°C to 34°C, with warmer conditions possible in some areas during the daytime.
Caraga
The entire Caraga forecast area—including Agusan del Norte, Agusan del Sur, Surigao del Norte, Surigao del Sur and Dinagat Islands—is expected to have partly cloudy to cloudy conditions with rainshowers or thunderstorms.
Agusan del Sur could reach around 35°C, making it one of the warmest areas in the regional forecast, while other Caraga provinces may see maximum temperatures in the low to mid-30s Celsius.
BARMM
Across the Bangsamoro Autonomous Region in Muslim Mindanao, partly cloudy to occasionally cloudy skies with rainshowers or thunderstorms are expected in Cotabato City, Basilan, Lanao del Sur, Sulu, Tawi-Tawi, Maguindanao del Norte and Maguindanao del Sur.
Temperatures may range from approximately 23°C to 35°C, with the highest forecast temperatures expected in Maguindanao del Sur.
Weather conditions may change rapidly
PAGASA’s forecast underscores that Mindanao could experience a mix of fair periods and sudden thunderstorms rather than uniform rainfall throughout the day.
Communities should therefore avoid relying solely on conditions observed early in the day. Thunderstorms can develop later and bring abrupt changes in rainfall intensity, wind and visibility.
Residents are advised to monitor official PAGASA updates and local disaster risk-reduction advisories, particularly if thunderstorms become severe.
The forecast is valid from 5:00 a.m. September 19 until 5:00 a.m. September 20, 2026.