Humidity
Relative humidity is high in the Philippines. A high amount of moisture or vapor in the air makes hot temperatures feel hotter. This quantity of moisture is due to different factors - the extraordinary evaporation from the seas that surrounds the country on all sides, to the different prevailing winds in the different seasons of the year, and finally, to the abundant rains so common in a tropical country. The first may be considered as general causes of the great humidity, which is generally observed in all the islands throughout the year. The last two may influence the different degree of humidity for the different months of the year and for the different regions of the Archipelago.
In the cooler months, even though the rains are more abundant in the eastern part of the Philippines, owing to the prevailing northeasterly winds, the humidity is lesser than in the western part where a dry season prevails. From June to October, although the rains are quite general throughout the Archipelago, the rains are more abundant in the western part of the Philippines, which is more exposed to the prevailing westerly and southwesterly winds; hence the humidity of the air is greater there than in the eastern part of the Archipelago.
The least comfortable months are from March to May where temperature and humidity attain their maximum levels.
Read more about this topic: Climate Of The Philippines