We’re only three months into 2026, but the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) has already begun recording considerably high heat indices.
The island of Coron in Palawan registered a staggering 42°C heat index for three consecutive days on March 3, 4, and 5. The town of Casiguran in Aurora also recorded the same heat index on March 6.
The state weather bureau classifies this level of heat under the “danger” category, wherein heat cramps, heat exhaustion, and heat strokes are likely to happen under continued sun exposure.
These readings arrive even before the dry season fully kicks in. This signals an early and potentially intense onset of extreme heat across the country.
In last year’s Global Climate Highlights report by the Copernicus Climate Change Service (C3S), 2025 was ranked as the “third warmest year on record.” It fell right behind the “unprecedented” temperatures logged in 2023 and 2024.
But last year was only “marginally cooler” than 2024. PAGASA noted that 2024 was the hottest year in the Philippines due to the El Niño phenomenon, among other factors.
In 2015, global leaders signed the Paris Agreement, pledging to limit long-term global warming to 1.5°C above pre-industrial levels. Crossing this limit triggers severe climate tipping points, the United Nations said.
The Intergovernmental Panel on Climate Change stated in its latest synthesis report that human activities unequivocally caused this unprecedented heating.
As the unabated rise in temperatures forces us to look beyond daily weather updates, we need to understand how long-term heat risks will alter our way of life.
How exactly do we measure this heat, and who bears the brunt of a warming planet?
When we check our weather apps, the first number we usually see is the air temperature. This represents the actual heat in the air as measured by a thermometer.
But this figure rarely tells the whole story. To understand what our bodies actually experience, meteorologists look at the heat index.
PAGASA defines the heat index as the “apparent temperature” or what we actually feel on our skin. The state weather bureau calculates this by combining the baseline air temperature with relative humidity, which is simply the amount of moisture present in the air.
In a 2025 study published in the International Journal of Biometeorology, researchers from Princeton University and the National Oceanic and Atmospheric Administration detailed how extreme humidity amplifies thermal or heat stress on vulnerable populations.
Our bodies naturally cool down by sweating. When sweat evaporates, it pulls heat away from our skin. But high humidity disrupts this biological defense mechanism.
“When humidity rises, it becomes harder for sweat to evaporate, making it more difficult for the body to cool down,” the researchers wrote.
This biological disruption forces the human body to perceive the environment as much hotter than it actually is, they added. This means that an air temperature of 35°C can quickly feel like a staggering 42°C heat index.
High heat indices are dangerous on their own. But when these scorching temperatures persist for days, they turn into what we now call heatwaves.
The World Meteorological Organization defines a heatwave as a period of unusually hot weather that lingers for two or more days. It often happens outside a region’s historical averages.
These prolonged periods of extreme temperatures take a massive toll on human health, the World Health Organization noted. This risk multiplies exponentially when high humidity traps the heat.
When the human body fails to cool itself, it can trigger severe dehydration, heat exhaustion, and fatal heatstroke.
Extreme heat also acts as a threat multiplier for people with pre-existing conditions. The WHO added that heatwaves can worsen chronic illnesses, sparking asthma attacks, heart complications, and kidney problems.
From January 1 to April 18, 2024, the Department of Health (DOH) logged 34 cases of heat-related illnesses, leading to six fatalities. In 2023, the DOH tallied a total of 513 for the entire year.
In 2024, a World Weather Attribution report revealed that human-caused climate change brought an additional month of extreme heat for four billion people worldwide that year.
The Philippines is intimately familiar with this extended exposure.
The rising toll of extreme heat is already scorching the country’s future, the Global Disaster Preparedness Center stated. Prolonged heat disrupts daily routines, strains public health systems, and severely diminishes labor productivity.
In 2024, the brutal heatwaves forced in-person class suspensions across the country. Millions of students had to shift to alternative delivery modes to avoid hazardous temperatures inside cramped classrooms.
The following year, Malacañang and DepEd issued localized guidelines to protect learners and teachers alike from the dangers of relentless heat exposure.
To understand where our climate is heading, we have to look at how much it has already changed.
When climatologists track global warming, they often look at key indicators. According to the C3S, a couple of them include surface air temperature and the sea surface temperature.
Surface air temperature is measured two meters above the ground. This represents the actual air we breathe and experience every day.
Meanwhile, sea surface temperature tracks the heat of the water right at the ocean’s top layer.
Historical data from the European Centre for Medium-Range Weather Forecasts paints a stark picture of the Philippines’ changing climate.
To see the local impact, Fyt utilized AI-assisted coding to process the global dataset and isolate data specific to the Philippines. A centered moving average was then applied to smoothen out seasonal variations, allowing the focus to remain on the long-term temperature trend.
The resulting numbers show a clear and alarming trajectory.
In the 1940s, the country's average surface air temperatures usually hovered between 24°C and 26°C. But recent figures from 2024 and 2025 show these baseline temperatures regularly breaching the 28°C mark.
PAGASA documented this shift in its own historical observations. From 1951 to 2010, the country’s annual mean temperature rose by 0.648°C, the agency said.
The state weather bureau also reported more frequent hot days and fewer cold nights.
Ocean temperatures show a similar, alarming climb. Sea surface temperatures rarely exceeded 29°C in the mid-20th century. Today, they routinely cross 30°C during the dry season.
Warmer seas act as massive batteries for extreme weather. As the ocean surface heats up, it fuels the rapid intensification of storms, the C3S noted.
This compounding risk is already reflected in the country's immediate weather forecast.
PAGASA's climate outlook report for March to August 2026 anticipates that most parts of the country will experience near-normal to above-normal mean temperatures.
“Starting May, slightly-warmer-than-average to warmer-than-average temperatures are forecast to prevail over most areas nationwide,” the state weather bureau said.
Six to 14 tropical cyclones will likely enter or develop within the Philippine Area of Responsibility during this six-month period, it added.
But the threat extends far beyond the current year.
The World Bank projects the Philippines' compounded heat risk as “high” in the coming decades. Under a high-emission scenario, the Climate Knowledge Portal’s projections show these hazards rapidly worsening from 2020 to 2099.
While the country currently sits in “high heat” categories, the hazard maps violently turn red by mid-century as “very high heat” blankets larger portions of Luzon, Visayas, and Mindanao.
This means prolonged exposure to extreme, life-threatening heat is expected to become a regular occurrence in the coming decades.
By the 2080s, massive blocks of “extreme heat” risk will ultimately dominate the entire archipelago. This effectively turns life-threatening heat from a rare seasonal anomaly into a daily reality for millions of Filipinos living in densely populated areas.
Without massive systemic interventions, these escalating temperatures will continually devastate agricultural yields, paralyze outdoor labor, and permanently strain an already burdened public health system, the institution noted.
The pressing need to survive rising temperatures forces us to reconsider how we build our cities.
When heatwaves strike, our immediate reflex is to crank up the air conditioning. But relying solely on energy-intensive cooling systems is a flawed and unsustainable solution: It pumps more greenhouse gases into the atmosphere and worsens the very crisis we are trying to escape.
To truly protect communities, civil society organizations and urban planners push for long-term, nature-based interventions.
A primary recommendation is the aggressive development of green infrastructure.
In a 2024 global report, the United Nations Development Programme (UNDP) highlighted how integrating natural elements into urban spaces drastically mitigates the urban heat island effect.
Effective strategies must prioritize passive cooling methods that harness natural elements to regulate temperatures without draining the power grid, the UNDP Accelerator Labs Network wrote.
These green spaces not only absorb trapped heat but also manage severe floods during the rainy season.
Renowned Filipino architect and urban planner Felino “Jun” Palafox Jr. has continually championed the development of “sponge cities” as part of the country’s green infrastructure. Cities must be designed with porous and permeable surfaces, he noted.
In a November 28, 2020 webinar covering multi-sectoral approaches to climate resilience, Palafox explained that this nature-based approach allows cities to absorb or harvest rainwater to be repurposed for irrigation and fire prevention, and cool the surrounding air like a giant sponge.
He warned that ignoring these integrated green solutions and settling for a “do-nothing scenario” will only lead to catastrophic consequences for highly populated areas.
But physical infrastructure alone cannot save vulnerable populations. The Climate Change Commission (CCC) noted that the continuous rise in heat indices requires a systemic and unified response.
In an April 2024 statement, the climate body urged all sectors of society to brace for the escalating impacts of extreme heatwaves.
Robert Borje, CCC’s vice chair and executive director, noted that the government has already drafted a National Adaptation Plan to fortify the country against climate threats. The blueprint aims to reduce public vulnerability by building adaptive capacity and resilience into existing state policies, he stated.
But the climate body warned that these frameworks need urgent implementation before the crisis worsens.
Ultimately, surviving this climate emergency requires a massive shift in how we live, build, and govern. The relentless rise in temperatures is a stark reminder that extreme heat is no longer a distant threat, but a present danger.
To survive the boiling years ahead, communities must recognize the direct link between a shifting climate and public health.
“Our heightened awareness and improved understanding of the nexus between climate change and health is critical to ensure Filipinos remain prepared and able to adapt,” the climate body said. – fyt.ph
Alfon Cabanilla contributed research to this story. He is an editorial intern from Ateneo de Manila University.
