The Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) said 43 areas may still experience a "dangerous" heat index on Friday, May 31.

PAGASA said a heat index of 47 degrees Celsius (°C) may be experienced in Aparri, Cagayan, while 46°C may be felt in Laoag City, Ilocos Norte; Dagupan City, Pangasinan; and Tuguegarao City, Cagayan.
MMSU, Batac, Ilocos Norte; Baler, Aurora; Casiguran, Aurora; Alabat, Quezon; and Catarman, Samar may experience a 45°C heat index.
PAGASA added that Sinait, Ilocos Sur; Bacnotan, La Union; ISU Echague, Isabela; Infanta, Quezon; Virac Catanduanes; Catbalogan, Samar; Tacloban City, Leyte; and Butuan City, Agusan Del Norte may have a heat index of 44°C.

Meanwhile, a 43°C heat index may be recorded in Sangley Point, Cavite; Ambulong, Tanauan Batangas; Masbate City, Masbate; CBSUA-Pili, Camarines Sur; Mambusao, Capiz; Guiuan, Eastern Samar; Maasin, Southern Leyte; and Zamboanga City, Zamboanga Del Sur.
NAIA, Pasay City; Calayan, Cagayan; NVSU-Bayombong, Nueva Vizcaya; Iba Zambales; CLSU Muñoz, Nueva Ecija; Calapan, Oriental Mindoro; San Jose, Occidental Mindoro; Puerto Princesa City, Palawan; Daet, Camarines Norte; Legazpi City, Albay; Juban Sorsogon; Roxas City, Capiz; Iloilo City, Iloilo; Dumangas, Iloilo; Mactan International Airport, Cebu; Siquijor, Siquijor; VSU-Baybay, Leyte; and Dipolog, Zamboanga Del Norte may have a heat index of 42°C.