Heat indices in 14 areas reached the “danger” level on Tuesday, Aug. 15, but they were lower than the “extreme” heat index recorded in Casiguran, Aurora the day before.

The Philippine Atmospheric, Geophysical, and Astronomical Services Administration (PAGASA) recorded the day’s highest heat index of 45 degrees Celsius (°C) in Baler and Casiguran, both in Aurora province.

This was significantly lower compared to the 60°C recorded in Casiguran on Aug. 14.

According Marcelino Villafuerte II, PAGASA’s chief of Impact Assessment and Applications Section of the Climatology and Agrometeorology Division, coastal regions with low elevation usually have high heat indices, which is determined by the ambient temperature and humidity.

In addition to Baler and Casiguran, 12 other areas also experienced dangerous heat indices on Tuesday: Tuguegarao City, Cagayan (43°C); Infanta, Quezon (43°C); Calapan, Oriental Mindoro (43°C); Catbalogan, Western Samar (43°C); NAIA, Pasay City (42°C); Dagupan City, Pangasinan (42°C); Aparri, Cagayan (42°C); Sangley Point, Cavite (42°C); Ambulong, Tanauan, Batangas (42°C); Daet, Camarines Norte (42°C); Virac, Catanduanes (42°C); and Juban, Sorsogon (42°C).

Heat index describes how the human body perceives temperature.

PAGASA said a heat index ranging from 42°C to 51°C indicates impending “danger,” as “heat cramps and heat exhaustion are likely,” and “heat stroke is probable with continued activity.”

Meanwhile, a heat index above 52°C indicates “extreme danger” as “heat stroke is imminent.”

Due to the prevalence of the southwest monsoon, or “habagat,” scattered rain showers and thunderstorms may persist in Oriental Mindoro, Occidental Mindoro, Marinduque, Romblon, Palawan, Albay, Sorsogon, Masbate, Visayas, Zamboanga Peninsula, Northern Mindanao, and Caraga on Wednesday, Aug. 16.

PAGASA warned of the possibility of flooding or landslides in these areas due to moderate to occasional heavy rains.

Meanwhile, the rest of the country may continue to experience warm weather due to partly cloudy to cloudy skies with a chance of isolated rain showers or thunderstorms possible in the afternoon or evening.