Temperature wise, Boracay is nice and warm any time of the year. It's so close to equator that temperature is always between 24-30C (75-86F). Very comfortable all year round and you will never get cold no matter when you visit!
What to watch out for is the rain season, which starts around May-June and ends in October-November
December-April is the dry season and is the most comfortable time to visit Boracay
December-February and April are also very busy tourist seasons, so I recommend visiting in late November, March, or early May to avoid the crowds while still avoiding the rainy season