The heat index combines both temperature and humidity to measure how
the heat "feels" to the body. But even without gauging for humidity,
actual temperatures in the Philippines are rising as it is during the
dry season.
At Science Garden in Quezon City and the Ninoy Aquino International
Airport (NAIA) in Pasay, maximum temperatures this dry season — which
runs from March to May — are already trending their highest since at
least 2000, data from WeatherManila, an independent weather research
institute, showed.
Pagasa's own data show a bleaker picture. Not only are maximum
temperatures rising, the baseline, too, and at a faster rate. The
phenomenon is also not isolated to dry months, and is happening
all-year round.
Apart from time, location also matters. While broadly, minimum
temperatures are climbing, the pace and scale of warming tend to vary
across specific locations, and urbanization plays a key role.
Hot, hot, hot in the Metro
Maximum daily temperatures in Pagasa stations in Metro Manila
Note: No 2013 data for Science Garden. Data runs until May 3 for
2024.
Source: WeatherManila
While the Philippines generally has a tropical climate throughout the
year, the dry months are especially hot. Some locations also tend to
be generally warmer or cooler than the others.
For instance, in May last year, Tacloban's minimum temperature reached
26.1 degrees Celsius, nearly a percentage-point cooler than that
recorded in NAIA in Pasay at the time.
On paper, Tacloban and Metro Manila, where NAIA is located, are both
classified by the government as
highly urbanized cities. But in reality, Gerry Bagtasa, professor at the Institute of
Environmental Science and Meteorology at the University of the
Philippines-Diliman, said varying levels of urbanization may mean heat
is felt differently in these cities.
"In urban areas, land use/cover is mostly built up, as opposed to
mostly vegetation in rural. Ground mainly made up of concrete with
little vegetation (little evaporation) tends to make urban hold heat
more…and longer, resulting in higher nighttime temps," said Bagtasa,
also the founder of
WeatherManila.
Philippine cities warm up but at varying degrees
Minimum monthly temperatures in Pagasa stations located in highly
urbanized cities during the dry months
Note: Data only includes highly urbanized cities where a Pagasa
station is located, excluding Baguio City.
Source: Pagasa
A
2021 study
published on the International Journal of Climatology found the
so-called "urban heat island effect" even in Baguio, where climate is
much colder than the rest of the archipelago because of its high
altitude. On a yearly basis, Baguio's average minimum temperature rose
1.5 degrees Celsius from 2014 to 2023, Pagasa data showed.
Temperatures in the city, situated about five hours north of Manila,
drop between December and February. During that period last year, it
fell as low as 14.4 degrees Celsius in a month, still low than most of
the Philippines, but was already about two degrees Celsius up from a
similar period five years ago and nearly five Celsius warmer than
2014.
Cold, but not as cold
Minimum monthly temperatures in Baguio are on the rise during its
coldest months
Temperatures are already breaking new records this year, but Pagasa
said the worst is yet to come and intense heat is likely to persist
until mid-May.
On the ground, the government and the private sector are already
taking measures to alleviate the impact of extreme heat on the public.
Remote working, which became prevalent during the height of pandemic,
is returning while students also
get back online
to study in areas where schools are forced to shut down due to rising
temperatures. The Supreme Court has ordered judges to check on the
impact of heat on inmates in typically
congested jails.
More contingencies may be needed, as more humid weather is likely here
to stay. Baseline temperatures typically recorded during evenings are
rising "twice as fast" as their maximum counterparts, Bagtasa said.
The shrinking gap between minimum and maximum temperatures means less
reprieve from heat during daytime even after the sun sets. Hence,
nights are only bound to get hotter.
Mind the gap
The
gap between minimum and maximum temperatures
in a month in most Pagasa stations is narrowing
Source: Author's analysis of Pagasa stations data
Note
Heat index numbers are based on reporting by Pagasa at 5 p.m. daily.
Pagasa said the numbers are preliminary and may be subject to change
later.
