MANILA — State weather bureau PAGASA on Tuesday said current maximum temperature forecasts for May will be recomputed as actual temperatures next month may surpass currently published forecasts of extreme temperature.

This, after the agency recorded a temperature of 40 degrees Celsius in Echague, Isabela on Monday which is 0.3 degrees higher than the initial forecast. This, so far, is the highest temperature recorded in the Philippines for 2024.

Ana Liza Solis, chief of PAGASA's Climate Monitoring and Prediction Section, said this means there is a one-in-two chance that the mercury will rise even further in May.

“Possible pa po na higher than 40 degrees ang possible in terms of maximum daytime temperature. Kasama po niyan kung halimbawa medyo mainit din 'yung ating nighttime temperature. Kung pinag-combine, ito mas mainit,” she said.

(It’s possible that maximum daytime temperatures can reach higher than 40 degrees. If nights are also warm then this will combine with warm days making the next day even warmer.)

Meanwhile the mercury in Metro Manila hit 36.9 degrees Celsius — just a few point below the forecast maximum temperature of 38 degrees.

Solis explains residents in urban areas must also be vigilant of the urban heat island effect which sees warmer temperatures due to excessive concrete, steel, glass and other structures which store and emit more heat.

PAGASA said there is a way to determine whether a particular day will be warm. 

The absence of clouds, for instance, means direct sunlight is radiated towards the ground thereby raising temperatures during the day. 

If this is coupled with a cloudy evening, heat will be trapped near the ground as it is not able to escape to the atmosphere. This combination, Solis said, will mean warmer temperature the following day.

As cases of heat exhaustion and heat stroke have been logged in different parts of the country, experts continue to remind the public to increase awareness on various measures to prevent heat stress during periods of extreme temperatures.