The El Niño phenomenon is still having a significant impact on the country's temperature, with a peak of 45° Celsius expected on Monday at Central Bicol State University of Agriculture in Pili Camarines Sur.

Additionally, three other areas are forecasted to experience temperatures of 44 °C. These are Infanta, Quezon; Puerto Princesa City; and Aborlan in Palawan.

Moreover, 42°C is also expected in five areas: Tuguegarao City in Cagayan, Roxas City in Capiz, Iloilo City and Dumangas in Iloilo, and Catarman, Northern Samar.

The lowest forecasted heat index is projected at Baguio City and Benguet State University in La Trinidad at 28°C and 29°C, respectively.

The heat index, as defined by PAGASA, is the human discomfort index that gives the "apparent" temperature, or what humans perceive or feel as the temperature affecting their body.

The effect-based danger classification is between 42°C and 51°C, and its effects on the body are likely to be heat cramps, exhaustion, and probable heat stroke with continued exposure.

Taking of preventive measures, such as limiting time spent outdoors, drinking plenty of water, and wearing protective and comfortable clothing outdoors, is strongly advised by the government to the public to avoid heat-related illnesses which symptoms may consist of sweating heavily, exhaustion, dizziness, loss of consciousness, vomiting, a feeling of nausea, and weakness even with a rapid heartbeat.