As the holiday season draws closer, two distinct weather systems are currently shaping the atmospheric conditions across the archipelago. In its latest bulletin issued this Thursday, December 18, 2025, the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) highlighted the combined influence of the Intertropical Convergence Zone (ITCZ) and the Northeast Monsoon, locally known as Amihan.
Heavy Rains and Thunderstorms in the South
The ITCZ, a region where winds from the northern and southern hemispheres meet, is currently centered over southern Mindanao. Residents in Caraga, the Davao Region, Sarangani, South Cotabato, Basilan, Sulu, and Tawi-Tawi, as well as the island province of Palawan, should prepare for a damp day. PAGASA warns of cloudy skies with scattered rains and thunderstorms.
Due to the possibility of moderate to heavy rainfall, the state weather bureau has issued a cautionary note regarding potential flash floods and landslides in these areas. Local disaster risk reduction offices are advised to monitor high-risk zones closely.
The Amihan Surge in Luzon
In the north, the Northeast Monsoon continues to exert its influence, bringing cooler air and persistent moisture. Cagayan Valley, Aurora, Quezon, and the mountainous provinces of Apayao, Kalinga, Mountain Province, and Ifugao are expected to experience cloudy skies with consistent rains. Like the southern regions, these areas face risks of landslides, particularly in hilly terrains.
In contrast, the Amihan will provide a much milder experience for Metro Manila, the Ilocos Region, and the rest of Central Luzon. These areas can expect partly cloudy to cloudy skies with only isolated light rains, which are not expected to have any significant impact on daily commutes or outdoor activities.
Easterlies and Coastal Conditions
The Easterlies—warm winds blowing from the Pacific—are also active, affecting the Bicol Region and the provinces of Northern and Eastern Samar. These areas will see scattered rains and thunderstorms. For the rest of the country, localized thunderstorms may still occur, bringing brief but potentially severe rainshowers.
Mariners and coastal residents should remain vigilant as maritime conditions are quite active:
- Northern and Eastern Luzon / Eastern Visayas: Moderate to strong winds from the Northeast will result in moderate to rough seas, with wave heights reaching up to 3.4 meters.
- Mindanao: Coastal waters will remain relatively calmer, ranging from slight to moderate.
Temperature and Humidity
Reflecting the typical December climate, yesterday’s temperature peaked at 30.7°C at 3:00 PM and dipped to a refreshing 23.5°C early this morning. Humidity remains high, fluctuating between 64% and 94%.