13 areas hit 'danger' heat index on May 4, 2026 — PAGASA

The state weather bureau PAGASA warned that 13 areas are expected to experience a “danger” level heat index on Monday, May 4, 2026.

Based on its five-day heat index forecast, the following areas may record heat index values ranging from 42°C to 44°C:

• Sinait, Ilocos Sur – 43°C
• Laoag City, Ilocos Norte – 43°C
• Dagupan City, Pangasinan – 44°C
• MMSU, Batac, Ilocos Norte – 42°C
• Bacnotan, La Union – 43°C
• Aparri, Cagayan – 42°C
• Tuguegarao City, Cagayan – 42°C
• San Ildefonso, Bulacan – 42°C
• TAU Camiling, Tarlac – 42°C
• San Jose, Occidental Mindoro – 42°C
• Cuyo, Palawan – 42°C
• Maasin, Southern Leyte – 42°C
• Davao City, Davao del Sur – 42°C

Meanwhile, 61 areas—including two in Metro Manila—are forecast to experience “extreme caution” heat index levels, or 33°C to 41°C.

Tanay, Rizal is the lone area expected to fall under the “caution” level, with a heat index of 32°C.

On the other hand, the following areas may register “not hazardous” heat index levels, or below 27°C:

• Baguio City, Benguet – 26°C
• BSU, La Trinidad, Benguet – 25°C
• Benguet Radar, Tuba, Benguet – 22°C

The heat index reflects how hot it feels to the human body by combining air temperature and relative humidity. High humidity slows the evaporation of sweat, making it harder for the body to cool itself.—MCG GMA News