In response to the serious implications of changes in the local climate, this study describes the temporal and spatial rainfall variability in the Philippines. Precipitation and wet-day frequency are obtained from the 0.5-degree resolution gridded dataset of monthly surface climate of global land areas, excluding Antarctica, of the Climatic Research Unit (CRU) for the period of 1901-1990. Results indicate that high variability is located over areas during their respective rainy seasons. Among the three major islands, the rainfall in Luzon is more spatially variable during the wet and dry seasons. This may illustrate that the area is composed of different climate zones. Aside from standard deviation, a new indicator of variability based on rainfall intensity is proposed in this study. It is found that the last decade is characterized by a high rainfall intensity, which lasted the entire wet season. Information derived from this study may be used in effective land use planning and in updating the Coronas climatological atlas.
[Presented at the Samahang Pisika ng Pilipinas (SPP) Congress, 2004.]