THE HEAT index, or the temperature actually felt by the body, came close to extremely dangerous levels last Monday in Pangasinan.
The weather bureau said the heat index at its weather station in Dagupan City on Monday climbed to 48.4 degrees Celsius in the early afternoon.
This was the highest heat index recorded since the Philippine Atmospheric, Geophysical and Astronomical Services Administration (Pagasa) resumed temperature monitoring on March 1, as the summer season kicked in.
The heat index, also called the human discomfort index, is measured based on the air temperature and humidity to give the actual temperature felt by the body. High air temperature and high relative humidity will result in a high heat index.
Pagasa-weather specialist Mar Villafuerte said the Pangasinan heat index was recorded at 2 p.m. on Monday when the air temperature was at 34.3 degrees Celsius and the relative humidity or moisture content in the air was at 71 percent.
This surpassed the 46.5 degrees Celsius maximum heat index that Pagasa recorded in Dagupan City on March 18.
The average heat index for Pagasa’s 53 weather stations around the country that day was about 35 to 36 degrees Celsius.
Pagasa considers it the “danger level” once the heat index breaches 41 degrees Celsius, warning of heat cramps, heat exhaustion and heat stroke from continued activity under the sun.
The “extreme danger level” is reached when the heat index reaches 54 degrees Celsius and above.
The other areas where the heat index reached dangerous levels on Monday were General Santos City, South Cotabato, with a maximum heat index of 45.6 degrees Celsius; Cabanatuan City, Nueva Ecija, with 44.2 degrees; Sangley Point, Cavite, with 41.3 degrees; Cotabato City, Maguindanao, with 41.2 degrees; Dipolog City, Zamboanga del Norte, with 40.9 degrees; Ambulong, Batangas, with 40.5 degrees; and Maasin, Southern Leyte, with 40.4 degrees Celsius.
The recorded heat index at the Pagasa Science Garden in Quezon City rose to 37 degrees Celsius on Monday.
Villafuerte said the high heat index recorded in General Santos City was due to the high temperature brought about by unobstructed solar radiation.
He said Nueva Ecija’s topography as a valley limited wind circulation, contributing to the high temperature, while Cavite experienced high humidity due to its proximity to Manila Bay.
Pagasa gives a weekly forecast of the maximum heat index in 13 major cities on its website (www.pagasa.gov.ph). It reports the actual heat index recorded in 53 weather stations the following day.
Villafuerte said they can only forecast the heat index in 13 cities where air temperature forecast is available.
He said they cannot yet issue a warning since the heat index categories are based on United States records and have not been empirically validated in the Philippines.
“We need to collaborate with the Department of Health to determine the impact of a given value (of the heat index).”