The Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) has issued a heat index watch, indicating that three areas are expected to reach 'danger' levels this Friday. This warning comes as the heat index in Aparri has already been reported at dangerous levels.
Residents in affected areas are advised to take precautions to avoid heat-related illnesses as temperatures rise. The forecasted heat index for April 23, 2026, in One North Central Luzon is also expected to contribute to the elevated heat conditions.