What Was The Hottest Temperature Ever Recorded in the Philippines?
A heatwave was reported to affect nations across Southeast Asia on April 4, according to Swiss air quality technology company IQAir. This is attributed to both the El Niño event sweeping through the region and human-induced climate change, leading to unprecedented high temperatures in the Philippines, Indonesia, Thailand, Myanmar, Vietnam, and Malaysia.
But while Filipinos, especially in urban centers like Metro Manila, are experiencing what's probably the worst heat conditions amid the dry season, current temperatures are not the highest on record in the country.
Hottest Day on Record in the Philippines
A temperature of 42.2 degrees Celsius was recorded in Tuguegarao, Cagayan Valley on April 22, 1912, and May 11, 1969. The hottest day on record in Metro Manila was on May 14, 1987, at 38.5 degrees.
Based on the Philippine Atmospheric, Geophysical, and Astronomical Services Administration's (PAGASA) records, the mean annual temperature in the Philippines (excluding Baguio) is 26.6 degrees Celsius. The warmest month occurs in May with a mean temperature of 28.3 degrees Celsius.
Early in 2024, the Copernicus Climate Change Service reported: "2023 is confirmed as the warmest calendar year in global temperature data records going back to 1850." The global average temperature is 14.98 degrees Celsius, which is 0.17 degrees higher than the previous highest value recorded in 2016.
Despite this global record, PAGASA said that 2023 was only the 11th warmest year in the Philippines. The year 1998 remains to be the hottest year on record, with an annual average temperature of 28.29 degrees.
The first few days of April only had maximum temperatures from 34 degrees to 38.4 degrees Celsius.
Unfortunately for the Philippines, the experience of heat is not only dependent on surface temperatures. There's also "heat index" to worry about.
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What is "heat index"?
PAGASA defines heat index as the "human discomfort index that gives the apparent temperature or what human perceive or feel as the temperature affecting their body." In simple terms, it is the "what it feels like" temperature. This is calculated by considering both the air temperature and relative humidity in an area. The thermometer may show a maximum temperature of only around 30 degrees Celsius, but if the percentage of humidity is nearing 100, then the heat index (recorded in degrees Celsius) can also be high.
The heat index from 32 degrees Celsius to 41 degrees Celsius is already in the "Extreme Caution" zone, which causes heat cramps and heat exhaustion. The heat index from 41 degrees Celsius to 54 degrees Celsius is already in the "Danger" zone. Heat index can go as high as 60 degrees Celsius, which happened in Dagupan City, Pangasinan on July 2, 2020.
As of writing, the highest index for 2024 is in Bacnotan, La Union, which was at 46 degrees Celsius on March 24.
In a previous exchange via SPOT.ph with University of the Philippines professor Dr. Gerry Bagtasa, who specializes in atmospheric physics, he enumerated three things as to why it is distinctly hot in Luzon, especially in Dagupan and La Union.
"First, as mentioned, we are in the tropics (or near the equator); this is why it's hot in the Philippines. It doesn't explain though why particularly in Central Luzon or Cagayan. Second, there's longer daytime than nighttime, so there is a longer time to heat up everything. Again, this explains for the whole northern hemisphere but not particularly in Central Luzon.
Third, it's the interaction between winds that are coming from the east or from the Pacific and the mountains. It creates what is known as Foehn winds, which are warm, dry air rolling down the lee or leeward side of mountains (the opposite side of the prevailing winds). Foehn winds are what make the air hot and not the easterly winds as typically explained. In Metro Manila, for example, it's also the Foehn winds that make it hot here because of the Sierra Madre mountains to the east," he explained.
He also noted that high air temperatures are usually observed in Central Luzon and Cagayan Valley, which holds the record for the highest temperature in the Philippines.
Whether it's high temperature or high heat index, the weather conditions in the Philippines during the dry season can lead to heat cramps, exhaustion, and even heat stroke. The weather bureau advises the public to limit outdoor exposure and drink lots of water.
