• Highest heat index for 2021 was 53℃ in Dagupan, Pangasinan, on May 14.
• On Tuesday, June 1, 18 weather stations around the country registered high heat index values that are within the “danger level” for heat cramps or heat exhaustion.
• The highest heat index of 51℃ was in Dagupan City, Pangasinan, while Aparri, Cagayan, and Sangley Point, Cavite recorded 50℃ on Tuesday, June 1.
• PAGASA defines “heat index” as a “human discomfort index” that gives the “apparent” temperature or what humans perceive or feel as the temperature that affects their body.
If you’ve been feeling extraordinarily warm in the past few days it was because the heat index in at least 18 weather stations around the country registered high numbers that are within the “danger” level for heat exhaustion.
The heat index in Dagupan City, Pangasinan reached 51 degrees Celsius (°C), while Aparri, Cagayan, and Sangley Point, Cavite recorded 50 degrees Celsius on Tuesday, June 1.
Based on the monitoring of the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA), 18 stations registered heat index values within the “danger” level due to the high likelihood of heat cramps and heat exhaustion.
The top 18 stations with high heat index values on Tuesday were: Dagupan City, Pangasinan (51℃, 2 p.m.); Aparri, Cagayan (50℃, 11 a.m.); Sangley Point, Cavite (50℃, 2 p.m.); Ninoy Aquino International Airport, Pasay City (46℃, 2 p.m.); Tuguegarao City, Cagayan (46℃, 5 p.m.); Ambulong, Batangas (45℃, 11 a.m.); Alabat, Quezon (44℃, 11 a.m.); Laoag City, Ilocos Norte (44℃, 2 p.m.); Clark Airport, Pampanga (43℃, 2 p.m.); Cubi Pt., Subic Bay, Olongapo City (43℃, 2 p.m.); Iba, Zambales (43℃, 11 a.m.); Itbayat, Batanes (43℃, 11 a.m.); Legazpi City, Albay (43℃, 11 a.m.); Science Garden, Quezon City (43℃, 2 p.m.); Casiguran, Aurora (42℃, 2 p.m.); Infanta, Quezon (42℃, 11 a.m.); Sinait, Ilocos Sur (42℃, 4 p.m.); Port Area, Manila (41℃, 11 a.m.).
The day before, on Monday, May 31, the highest heat index of 50°C was felt in Ambulong, Batangas, and in Sangley Point, Cavite.
In other parts of the country on Monday, the heat index was 47°C in Legazpi City, Albay; 46°C in Casiguran, Aurora, and in Dagupan City, Pangasinan; and 45°C in Clark Airport, Pampanga, and at the Ninoy Aquino International Airport.
Based on the monitoring of PAGASA, 20 stations registered heat index values within the “danger” level due to the high likelihood of heat cramps and heat exhaustion.
What is heat index?
PAGASA defines “heat index” as a “human discomfort index” that gives the “apparent” temperature or what humans perceive or feel as the temperature affects their body.
Air temperature is different from heat index as the latter is the measurement of how hot it feels when relative humidity is factored in with the actual air temperature.
Heat index is at least 3°C to 4°C higher than the actual air temperature. But PAGASA said that full exposure to sunshine can increase the heat index by 8 degrees Celsius.
Highest heat index in 2021
The highest heat index so far in 2021 was recorded in Dagupan City, Pangasinan on May 14 at 53℃.
PAGASA weather specialist Benison Estareja said hot weather conditions are expected in Pangasinan’s capital because it is part of the Agno River Valley.
Estareja likened Dagupan City’s condition to Tuguegarao City, Cagayan, and Echague, Isabela, which are also experiencing hot temperatures.
“Part kasi ang Dagupan City ng Agno River Valley, so mainit din talaga yung buong valley. Same with Tuguegarao (Cagayan) and Echague, Isabela na record-high din ang air temperatures. [Tuguegarao and Echague] are part of Cagayan Valley naman. (Because Dagupan City is part of the Agno River Valley, so the whole valley is really hot. Same with Tuguegarao, Cagayan and Echague, Isabela where air temperatures are also record-high. Tuguegarao and Echague are part of Cagayan Valley),” Estareja told the Manila Bulletin.
Sun exposure is also more intense in areas situated in a valley which makes the air warm faster, he said. “Areas beneath the valley form few clouds and [have] little rain, as compared to areas in and near the mountains. Mataas ang sun exposure (Sun exposure is more intense) plus air that enters the valley warm quickly.”
Observe extreme caution
With heat indicis between 32 to 41°C, PAGASA advised residents to observe “extreme caution” as “heat cramps and heat exhaustion are possible” and “continuing activity could result in heatstroke.”
Meanwhile, with heat indices between 41 and 54°C, PAGASA said there is impending “danger” as ” heat cramps and heat exhaustion are likely” and “heat stroke is probable with continued activity.”
If the heat index is over 54°C, PAGASA said there is “extreme danger” as “heat stroke is imminent.”
Tips to prevent heatstroke
1. Stay indoors as much as possible, if air conditioning is not available, stay on the lowest floor out of the sunshine.
2. Wear lightweight and light-colored clothing. Light colors will reflect the sun’s energy. Drink plenty of water regularly. The body needs water to keep cool.
3. Water is the safest liquid to drink during heat emergencies. Avoid drinking liquor because it dehydrates the body.
4. Eat small meals, however, eat more often. Avoid eating foods high in protein, which can increase metabolic heat.