The Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) warned that 33 areas, including Metro Manila, are at risk of reaching "dangerous" heat index levels on Friday, April 26.
PAGASA said the heat index may reach 47℃ in Dagupan City, Pangasinan, and 46℃ in Aparri, Cagayan, and Aborlan, Palawan.
A heat index of 45℃ may be recorded in Bacnotan, La Union; Cubi Pt., Subic Bay, Olongapo City; Sangley Point, Cavite; Coron, Palawan; and San Jose, Occidental, Mindoro; and 44℃ in Laoag City, Ilocos Norte; Tuguegarao City, Cagayan; Puerto Princesa City, Palawan; and Legazpi City, Albay.
Meanwhile, it may reach 43℃ in Pasay City, Metro Manila; Sinait, Ilocos Sur; Batac, Ilocos Norte; Echague, Isabela; Iba, Zambales; Muñoz, Nueva Ecija; Ambulong, Tanauan, Batangas; Pili, Camarines Sur; Roxas City, Capiz; and Dipolog, Zamboanga del Norte.
A 42℃ heat index may be recorded in Science Garden, Quezon City, Metro Manila; Tayabas City, Quezon; Alabat, Quezon; Virac, Catanduanes; Iloilo City, Iloilo; Dumangas, Iloilo; La Granja, La Carlota, Negros Occidental; Malaybalay, Bukidnon; Cotabato City, Maguindanao; General Santos City, South Cotabato; and Butuan City, Agusan del Norte.
Heat index is the measurement of how hot it feels when relative humidity is combined with the actual air temperature.
PAGASA said a heat index between 42°C and 51°C indicates impending "danger," as "heat cramps and heat exhaustion are likely," and "heat stroke is probable with continued activity."
Meanwhile, a heat index above 52°C indicates "extreme danger," as "heat stroke is imminent."