The Philippine Atmospheric, Geophysical, and Astronomical Services Administration (PAGASA), on Tuesday, May 28, said Guiuan, Eastern Samar, experienced a scorching 55 degrees Celsius (°C) heat index.

This matched the highest heat index recorded in the city on May 26 since the year started.
READ: PAGASA records highest heat index anew
This level falls under the "extreme danger" effect-based classification, where heat stroke is "imminent."
Meanwhile, PAGASA said Sangley Point, Cavite, and Virac (Synop), Catanduanes recorded a heat index of 48°C, followed by Butuan City, Agusan Del Norte at 46°C.
The heat index reached 45°C in Catarman, Northern Samar, while 44°C in Ninoy Aquino International Airport (NAIA) Pasay City, Metro Manila; Laoag City, Ilocos Norte; Dagupan City, Pangasinan; ISU Echague, Isabela; Casiguran, Aurora; Puerto Princesa City, Palawan; Cuyo, Palawan; and Tacloban City, Leyte.

A heat index of 43°C was logged in Science Garden Quezon City, Metro Manila; Aparri, Cagayan; Baler (Radar), Aurora; Infanta, Quezon; Alabat, Quezon; Masbate City, Masbate; CBSUA-Pili, Camarines Sur; Catbalogan, Samar; and Dipolog, Zamboanga Del Norte.
Meanwhile, it reached 42°C in Sinait, Ilocos Sur; MMSU, Batac, Ilocos Norte; Calayan, Cagayan; Tuguegarao City, Cagayan; Ambulong, Tanauan Batangas; Calapan, Oriental Mindoro; Romblon, Romblon; Daet, Camarines Norte; Legazpi City, Albay; Juban, Sorsogon; Roxas City, Capiz; Iloilo City, Iloilo; Panglao International Airport, Bohol; Mactan International Airport, Cebu; Siquijor, Siquijor; Borongan, Eastern Samar; and Maasin, Southern Leyte.
On May 28, 38 areas reached the "danger" heat index.