The Philippine Atmospheric Geophysical and Astronomical Services Administration (PAGASA) warns that the heat indices could reach up to 47 degrees Celsius in Dagupan City, Pangasinan; and Aparri, Cagayan.

PAGASA also said that the Ninoy Aquino International Airport in Pasay City could record a heat index of 42 degrees Celsius.

The weather-monitoring agency also predicts that 27 other areas will register danger level heat indices (between 42 degrees Celsius to 51 degrees Celsius).

These areas include:

• Sinait, Ilocos Sur;
• Laoag City, Ilocos Norte;
• Mariano Marcos State University in Batac, Ilocos Norte;
• Bacnotan, La Union;
• Tuguegarao City, Cagayan;
• Isabela State University in Echague, Isabela;
• Iba, Zamabales;
• Baler, Aurora;
• Casiguran, Aurora;
• Subic Bay, Olongapo City;
• Sangley Point, Cavite;
• Ambulong, Tanauan, Batangas;
• San Jose, Occidental Mindoro;
• Puerto Princesa City, Palawan;
• Cuyo, Palawan;
• Daet, Camarines Norte;
• Virac, Catanduanes;
• Masbate City, Masbate;
• The Central Bicol State University of Agriculture in Pili, Camarines Sur;
• Roxas City, Capiz;
• Iloilo City, Iloilo;
• Dumangas, Iloilo;
• Catarman, Northern Samar;
• Catbalogan, Samar;
• Tacloban City, Leyte;
• Borongan, Eastern Samar;
• Guiuan, Eastern Samar; and
• Dipolog, Zamboanga Del Norte