Wind Systems that Affect the Philippines

The Philippines experiences heavy rains from June to October and is very hot from February to May. These conditions can be explained by the wind systems affecting the country—the monsoons and the trade winds.

Monsoon
Within the year, land regions near the equator like the Philippines experience two opposite wind directions. This is caused by the unequal heating of the part between land masses and oceans. During summer, the land is heated more than the sea, creating a low-pressure area over the land. This causes the wind to move from the water to the land. During winter, the sea is heated more than the land, causing the wind to flow out to the water. These seasonal winds are called monsoons.

The northeast monsoon, locally known as amihan, is often experienced from October to March. It starts over Siberia as a cold, dry air that gathers moisture as it crosses the Pacific Ocean. This wind brings widespread cloudiness with rain showers to the eastern part of the country, as well as in Southern Luzon, Visayas, and Nothern Mindanao. The northeast monsoon is also responsible for the cold temperatures in the country.

The southwest monsoon, locally known as habagat, is often experienced from July to September. It blows a warm, humid wind from the Indian Ocean in the Southern Hemisphere. This wind causes the rainy season in the western part of the country, which includes the Bicol Region, Eastern and Central Visayas, Agusan del Norte, Agusan del Sur, and the Southern Tagalog Region.