Cloudy skies with scattered rains and thunderstorms are expected in various parts of the country on Saturday, May 31, according to the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA).
Frontal system, 'habagat' to bring rains, thunderstorms across parts of the Philippines on May 31
PAGASA weather forecast for May 31, 2025: Monsoon rains and thunderstorms to affect Luzon, Visayas, and Mindanao (KEITH BACONGCO / MANILA BULLETIN / FILE)
In its latest weather forecast, PAGASA highlighted the impact of a frontal system in Extreme Northern Luzon and the ongoing southwest monsoon (habagat) affecting the rest of the country.
Frontal system affecting Extreme Northern Luzon
PAGASA said Batanes and the Babuyan Islands will experience cloudy skies with scattered rain showers and thunderstorms due to a frontal system.
A frontal system marks the boundary where two air masses with distinct temperatures and humidity levels collide. Due to their density differences, warm and cold air resist blending, forming a transition zone known as a front.
This interaction frequently triggers cloudy skies, rainfall, and thunderstorms, particularly in regions where the system remains active.
PAGASA warned of possible flash floods and landslides in flood-prone and mountainous areas due to moderate to heavy rainfall.
‘Habagat’ over Luzon due to southwest monsoon
PAGASA noted that the southwest monsoon continues to bring rains to several provinces in Luzon, including the Ilocos Region, Apayao, Abra, Zambales, and Bataan.
Metro Manila and the rest of Luzon, PAGASA said, will also experience cloudy skies with scattered rain showers and thunderstorms due to the habagat.
Flash floods or landslides caused by moderate to occasionally heavy rains are possible in these areas, according to PAGASA.
Localized thunderstorms in Visayas and Mindanao
In the Visayas and Mindanao, PAGASA said partly cloudy to cloudy skies with isolated rain showers or thunderstorms are expected, brought about by localized thunderstorms.
PAGASA added that flash floods or landslides are possible during severe thunderstorms.