The Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) recorded the 54°C heat index at around 2 p.m., Friday, surpassing the 53°C heat index that was registered also in Dagupan City on March 17.

If the heat index is over 52°C, PAGASA said there is “extreme danger” as “heatstroke is imminent.”

Moreover, 10 other stations recorded between 42°C and 48°C heat index on Friday.

The stations that logged the highest heat index values on April 22 were:

Dagupan City, Pangasinan (54°C, 2 p.m.)

Sangley Point, Cavite (48°C, 2 p.m.)

Catarman, Northern Samar (45°C, 2 p.m.)

Iba, Zambales (45°C, 2 p.m.)

Virac, Catanduanes (44°C, 2 p.m.)

Aparri, Cagayan (43°C, 2 p.m.)

Daet, Camarines Norte (43°C, 2 p.m.)

Guiuan, Eastern Samar (42°C, 11 a.m.)

NAIA, Pasay City (42°C, 1 p.m.)

Port Area, Manila (42°C, 2 p.m.)

San Jose, Occidental Mindoro (42°C, 2 p.m.)

With heat indices between 41°C and 51°C, PAGASA said there is impending “danger as heat cramps and heat exhaustion are likely,” while “heat stroke is probable with continued activity.”

Heat index or apparent temperature differs from air temperature as it is the measurement of how hot it feels when relative humidity is factored in with the actual air temperature.

From March to May, PAGASA provides heat index monitoring and forecast information that can be viewed on their website.