ILOILO City — The Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) has temporarily stopped issuing heat index forecasts following the official onset of the rainy season, signaling a shift in weather monitoring priorities even as the threat of El Niño remains on the horizon.
PAGASA announced that daily heat index bulletins were suspended beginning June 5 after the agency formally declared the start of the rainy season.
Daily monitoring of the heat index and the issuance of forecasts will resume on March 1, 2027, coinciding with the country’s hot and dry months.
However, heat index information from PAGASA automatic weather stations and the iHeatMAP platform will remain accessible through the agency’s website.
PAGASA defines heat index as the measure of how high humidity combines with elevated temperatures, reducing the body’s ability to cool itself effectively.
The suspension comes after PAGASA officially declared the onset of the rainy season on June 4 across the western sections of Luzon and the Visayas.
“Based on the weather observations and analyses, occasional to frequent rains associated with the Southwest Monsoon (Habagat) have been observed over the past five days. This signifies the onset of the rainy season across the western sections of Luzon and the Visayas,” PAGASA said in a news release.
Earlier, the weather bureau announced the start of the southwest monsoon season, citing the prevailing southwesterly winds affecting the western section of the country.
The bureau said the southwest monsoon is “one of the precursors of the onset of the rainy season.”
Despite the arrival of the rainy season, PAGASA warned that monsoon breaks, or periods of reduced rainfall, may still occur and could last for several days or even weeks.
“Moreover, with the looming El Niño, enhanced Habagat rainfall over the western sections of Luzon and Visayas is highly likely during the season,” it added.
PAGASA earlier projected a 79-percent probability of El Niño developing during the June-July-August 2026 period and potentially persisting until early 2027.
The agency urged the public and concerned government agencies to continue taking precautionary measures against the impacts of the southwest monsoon and other prevailing weather systems./PN
