The Philippines has a humid equatorial climate characterized by high temperatures and heavy rainfall. Average annual rainfall is approximately 2,348 millimeters (mm), but this varies geographically, from 960 mm in southeast Mindanao to over 4,050 mm in central Luzon. Temperatures are generally high, particularly in the valleys and plains, averaging 27°C throughout the year. Humidity levels are high, averaging around 82% due to the warm moist trade winds that flow through the archipelago, as well as sea surface temperatures, a rich and vibrant vegetative cover and abundant rainfall. Rainfall is governed by the southwest monsoons in the summer months, and by the northeast monsoon and tropical cyclones in the winter. Convective rainfall is common due to the country’s mountainous terrain, interspersed with narrow coastal plains. The Philippines also experiences strong periodic droughts that are linked to the El Niño Southern Oscillation (ENSO). The Philippines’ hottest months are April and May, with the coldest months experienced during December, January and February. The mean annual temperature is 27.1°C, with a relatively low seasonal temperature variation of approximately 3°C. There is minimal spatial variation in temperatures across the country. Where temperature differences do exist, such as in Baguio City where the daily mean temperature is 19.6°C, elevation is significant factor. There is geographical variation in the distribution of precipitation: during June to September heavy rainfall is concentrated to the west of the country, whereas between October and March, heavy rainfall is predominantly found in the country’s eastern regions.
- A rise of 0.62°C in annual average mean temperature between 1958-2014 and a significant increase in the number of hot days and warm nights throughout the country between 1960-2003. Average increase per year for maximum temperature at 0.008°C and minimum temperature at 0.019°C.
- Warming trend in the Philippines between 1951-2010 through an observed increase in annual mean temperatures, daily minimum mean temperatures and daily maximum mean temperatures. These trends are similar to those experienced across the Pacific region in general. Estimated warming over Manila between 1900-2017 (average) and 2000-2017 (average) is 0.75°C.
- Warming over the same period in Davao in the south is estimated at 1.11°C (this higher value reflects the inland cover of the Davao grid cell) and 0.75°C in Puerto Princesa in the west.
- The Philippines has experienced a sharp increase in amount and intensity of rainfall as a result of climate change in recent years, with more rainy days observed since the 1990s.
- Wet conditions have increased during the dry season, with the five-year running average showing there are more tropical cyclones of typhoon intensity happening during El Niño events.