When does the Rainy Season begin in the Philippines?

The month of June signals the start, not only of classes, but also of the rainy season.

According to PAGASA, the onset of the rainy season will most likely commence in the second week of June. For it to be officially declared by the weather bureau, these three things need to happen:

1. A five-day period within April, May, June or July with a total rainfall amount of 25 millimeters or more with three consecutive days having at least 1 millimeter of rainfall per day. Said rainfall must be recorded at no less than five of these stations: Laoag, Vigan, Dagupan, Iba, Mindoro Occidental, Ambulong, Iloilo, and Metro Manila.

2. At least two out of three stations in Metro Manila must have satisfied the first criterion simultaneously.

3. Prevailing winds over the Western Philippines should have westerly to southwesterly components. The southwest monsoon commonly known as hanging habagat should also be the dominant wind system.

Meanwhile, most parts of the country will experience near normal rainfall. However, PAGASA Weather Forecaster Jun Galang said areas under code Yellow will have below normal or less rainfall this month. This includes Palawan, parts of Cordillera, National Capital Region (NCR), Dagupan, Zambales, Subic, Pangasinan, Tarlac and Pampanga.

Other weather systems such as Inter Tropical Convergence Zone (ITCZ) will be prevalent this month. This will bring light to moderate rain showers over a large part of Mindanao. This could also affect Visayas and Southern Luzon as it changes its axis.