The Philippine Atmospheric, Geophysical, and Astronomical Services Administration (PAGASA) said on Wednesday that the scattered rains experienced in the country in the past few days can be an indicator of the possible onset of the rainy season.

"The frequent rains every afternoon and evening are also one of our indications that it is possible that we will enter the rainy season in the next few weeks, depending on the assessments of our colleagues who are climatologists," PAGASA weather specialist Veronica Torres said in a radio interview.

She said that the rainy season is usually declared either late in May or earlier in June, further noting that warm weather may still be felt as El Niño still prevails in the country.

Torres said that during thunderstorms, heavy rains are possible that may last as short as 30 minutes and can last as long as two to three hours in severe cases.

She added that if thunderstorms happen frequently, there is a big chance that the country will be entering the rainy season.

"When the southwest monsoon, or Habagat, is already affecting us, that is an indication that we are in the rainy season," she said, adding that most storms usually enter or form in the Philippine Area of Responsibility from July to August.

PAGASA advised the public to avoid going to open fields and being near high structures such as posts and trees during thunderstorms.

"As much as possible, avoid bodies of water because they also conduct electricity. As much as possible, let's stay inside the establishment that is thunderproof," she added.

The weather bureau issued a La Niña watch alert in March, signifying that there is a level of more than 55 percent of its occurrence in the next six months.