The Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) said San Ildefonso, Bulacan registered the highest heat index in the country on Monday, April 21, reaching a sweltering 48 degrees Celsius (°C).
Dagupan City in Pangasinan followed with a heat index of 47°C, while Olongapo City in Zambales recorded 45°C.
Baler in Aurora and Camiling in Tarlac both registered 44°C.
A heat index of 43°C was observed in Tuguegarao City, Cagayan; Iba, Zambales; Puerto Princesa City, Palawan; Cuyo, Palawan; and Dumangas, Iloilo.
Meanwhile, Bacnotan, La Union; Calayan, Cagayan; Aparri, Cagayan; Casiguran, Aurora; Muñoz, Nueva Ecija; Tarlac City, Tarlac; Cavite City, Cavite; Aborlan, Palawan; Masbate City, Masbate; Pili, Camarines Sur; Daraga, Albay; and Catarman, Northern Samar all logged a heat index of 42°C.
The heat index, or “apparent temperature,” combines the actual air temperature with relative humidity to reflect how hot the environment feels to the human body.
READ MORE: https://mb.com.ph/2025/3/3/how-pagasa-s-heat-index-reports-help-you-prepare
PAGASA classifies heat indices between 42°C and 51°C as dangerous.
At this level, people are at increased risk of heat cramps and heat exhaustion. Prolonged exposure to such conditions could lead to heatstroke.