The Philippine Atmospheric, Geophysical, and Astronomical Services Administration (PAGASA) on Monday allayed public fears on the possible occurrence of heat wave in Metro Manila, following five consecutive days of temperatures ranging from 36.1 to 37.2 degrees Celsius in the metropolis.

PAGASA senior weather forecaster Robert Sawi said the temperatures are not yet considered heat wave.

From May 12 to 16 (Wednesday to Sunday), temperatures were 36.2, 36.1, 36.8, 36.6, and 37.2 degrees Celsius, respectively.

The temperature last Sunday of 37.2 degrees Celsius is 0.1-degree Celsius shy of the highest temperature recorded in Metro Manila last April 28 of 37.3 degree Celsius.

“Ang nararamdaman natin ay napakainit talaga. Lalo na mas mahaba ang exposure natin sa araw pero hindi pa natin ito masasabing heat wave, Sawi said. (“We are really experiencing hot weather condition. This is because we are exposed under the sun for a longer time but we still cannot say that this is a heat wave.”)

“Dahil dapat consistent itong papalo sa 37 to 38, pero nangyayari talaga na umaabot ng 36 degrees Celsius ang temperature kapag May,” he noted. (“Temperatures must be consistently at 37 to 38 degrees Celsius but temperature of 36 degrees Celsius is just normal especially during the month of May.”)

PAGASA Deputy Administrator for Operations and Services officer-in-charge (OIC) and weather branch chief Nathaniel Cruz earlier explained that heat wave may be declared when temperatures for five consecutive days register two or three degrees higher than the averag mean maximum temperature of 34 degrees Celsius in Metro Manila.

"Ine-expect talaga natin na mataas sa ganitong buwan ng Mayo. Dahil mataas din ang ating relative humidity mas dumagdag yun sa nararamdaman nating init,” Sawi said. (“We expect that temperatures during this month would be high. At present, the high relative humidity also contributes to the heat we are experiencing.”)

“Maaaring tumaas pa hanggang 37 ang temperature pero hindi na ito aabot sa 38 degrees Celsius,” he said. (“We also expect that temperatures may still rise to 37 degrees Celsius but it will not reach 38 degrees Celsius.”)

Sawi said the PAGASA is already monitoring the possible onset of rainy season by the last week of May or first week of June, as the current El Niño is likely to continue to weaken.

“Sa ngayon, magiging sunny pa rin bagamat magkakaroon pa rin ng isolated rainshowers sa hapon o gabi, particularly sa Metro Manila, Luzon at Visayas,” he said. (“For now, it will still be sunny except for the isolated rainshowers in the afternoon or  evening, particularly in Metro Manila, Luzon, and Visayas.”)

“Sa Mindanao nagkakaron ng cloudy skies dahil sa intertropical convergence zone,” he added. (“In Mindanao, cloudy skies will  prevail because of the ITCZ.”)

PAGASA said that days get longer in the Philippines due to summer solstice, an astronomical term regarding the position of the sun in relation to the celestial equator.

The summer solstice is the day of the year with the longest daylight period and hence the shortest night, which usually occurs  on June 21 or June 22 in the northern hemisphere.