The Philippines being near the equator only has two seasons: the dry season and the rainy season.
Travel books and most internet sites say that dry season in the Philippines starts in December and runs through to about June. Maybe ten years ago that was true but now the real dry season starts in January and runs through about May. April being the hottest month.
June is the beginning of rainy season in the Philippines. July to September will be like typhoon months. December will be a combination of rainy and sunny days.
Our pick for the best months to visit the Philippines is January to March.
BECAUSE 1. Rain is seldom almost none. 2. The heat is tolerable unlike in April.
3. The beaches aren't that crowded yet.
So what clothes should you bring? Depending on which month you'll be visiting, there's really just two types of clothing you can wear in our country. First would be summer clothing and second will be rainy days clothing.
Philippine summer(third week of March to second week of May) can be very, very, VERY hot. Temperature can go up to 40°C/ 104°F. So for summer clothing, it's best to bring sleeveless or short sleeved shirts and shorts. Denim jeans or denim trousers are also okay. Please don't forget to bring your sunglasses and summer hats.
Rainy days clothing in the Philippines = SUMMER CLOTHING + JACKETS. Even if it's rainy season, it never gets cold in this country. The coldest will be around 22 °C/71.6 °F. So for the jackets, it's best to bring the waterproof and hooded ones. Don't bring those thick jackets-they will keep you TOO warm and will be very uncomfortable. Also do NOT forget to bring a pair of rain boots that can go with any of your outfit. Some areas in Metro Manila become flooded during heavy rain. The water from the floods are dirtier than they look. It's safer to wear boots.
Let's say you're going to Baguio which is probably the coldest place in the country. A shawl and that waterproof jacket will be enough to keep you warm.
Hope this post helps. Bon voyage!