Rainfall
The summer monsoon brings heavy rains to most of the archipelago from May to October. Annual average rainfall ranges from as much as 5,000 millimetres (196.9 in) in the mountainous east coast section of the country, to less than 1,000 millimetres (39.4 in) in some of the sheltered valleys. Monsoon rains, although hard and drenching, are not normally associated with high winds and waves.
At least 30 percent of the annual rainfall in the northern Philippines can be traced to tropical cyclones, while the southern islands receiving less than 10 percent of their annual rainfall from tropical cyclones. The wettest known tropical cyclone to impact the archipelago was the July 1911 cyclone, which dropped over 1,168 millimetres (46.0 in) of rainfall within a 24-hour period in Baguio City.
Read more about this topic: Climate Of The Philippines