Dagupan City in Pangasinan had the highest heat index on Friday, April 5, based on the monitoring of the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA).
PAGASA said Dagupan City logged a heat index of 45 degrees Celsius (ºC), which falls within the “danger” category.
Four other locations also recorded dangerous heat indices on Friday.
These were in Catarman, Northern Samar (43ºC); Laoag City, Ilocos Norte (42ºC); Puerto Princesa City, Palawan (42ºC); and Roxas City, Capiz (42ºC).
PAGASA recorded the country's highest heat index so far this year at 48°C in Roxas City, Capiz on March 27.
It defines the heat index as the measurement of how hot it feels when relative humidity is combined with the actual air temperature.
It said a heat index ranging from 42°C to 51°C indicates imminent "danger," as "heat cramps and heat exhaustion are likely," and "heat stroke is probable with continued activity."