Haze blankets the Metro Manila skyline on the afternoon of August 31, 2026. Francis Orcio, ABS-CBN News
MANILA - Smoke from forest fires in Kalimantan, Indonesia, has reached Metro Manila and other parts of the Philippines, with an unusual wind pattern carrying pollutants across the equator toward the country, according to an atmospheric physicist from the University of the Philippines.
Dr. Gerry Bagtasa, an atmospheric physicist and professor of meteorology at the UP Institute of Environmental Science and Meteorology, said satellite imagery showed active fires in western and southern Kalimantan in recent days, coinciding with winds transporting smoke toward the Philippines.
“Apparently, dito sa may around Kalimantan, medyo malaki iyong fire in the past few days, in fact. Nagkataon ngayon na mayroon tinatawag na cross-equatorial na hangin,” Bagtasa said.
"From the southern hemisphere, dumadaan iyong hangin dito (Java Sea and South China Sea). And then siya iyong papunta dito sa many parts ng Pilipinas. So. we can see from the satellite image, iyong forest fire siya na nanggagaling from Kalimantan, umabot siya sa Pilipinas," he added.
Bagtasa said the current haze is unlikely to be explained solely by emissions from vehicles and factories in Metro Manila because strong winds would normally disperse locally generated pollutants.
Instead, strong winds combined with hazy conditions could indicate pollutants being transported from distant areas, he said.
The scientist said the prevailing southwest monsoon, or Habagat, is currently helping carry the smoke from Indonesia toward the Philippines.
Pilandok, two other weather disturbances enhance Habagat
LACK OF RAIN ALLOWS SMOKE TO TRAVEL FARTHER
According to Bagtasa, the unusual reach of the smoke is also linked to the lack of rain along its path.
Forest fires occur regularly in parts of Indonesia, particularly during its drier months. Under typical Habagat conditions, however, moisture and rainfall over the South China Sea can wash smoke and other pollutants out of the atmosphere before they reach the Philippines.
This time, the winds remain strong but there is less moisture and rain along the pathway of the smoke, allowing it to continue toward the country.
“Kasi kapag umulan, natatanggal niya iyong usok sa atmosphere. And most of the time, kung meron ganitong kalakas na hanging habagat, ang ibig sabihin, nagiging maulan around South China Sea,” Bagtasa said.
Bagtasa said the combination of persistent winds and the lack of rain in other parts of Southeast Asia and southern Philippines essentially allowed the smoke to travel uninterrupted.
He added that hazy conditions have also been observed in Region IV-A Calabarzon region, while portions of the Visayas and possibly Zamboanga may also be affected. Cloud cover, however, can make the haze more difficult to observe in some areas.
Unhealthy air quality recorded anew in Metro Manila
HAZE COULD PERSIST FOR SEVERAL DAYS
Bagtasa said the hazy conditions could persist for the next several days, particularly as weather systems north of the Philippines continue to influence the southwest monsoon.
“Pwede siyang mag-persist for the next several days. Pero may forecast na baka maging maulan by Wednesday, Thursday. So kung naging maulan, lalo na sa West Philippine Sea maging maulan, bago umabot iyong usok papuntang kalupaan ng Pilipinas, pwede siyang malinis tapos hindi aabot iyong usok. Pero kung magiging paulan," he explained.
Bagtasa also pointed to the possible interaction of weather systems north of the Philippines through the Fujiwhara effect, in which two nearby weather systems rotate around one another. Such an interaction can slow the movement of the systems and potentially prolong the winds contributing to the haze.
Bagtasa said the weather systems could continue affecting the winds until at least the end of the week.
“In the past few days sila na iyong nag-e-enhance [ng habagat]. Nag-move lang sila ng kaunti ngayon kaya medyo nawala iyong ulan sa atin. Pero hindi ibig sabihin na wala na sila. In fact, nand'yan pa rin sila hanggang sa, I believe, end of the week at the very least,” he said.
“So, itong hangin na nagdadala nitong usok na ito from Kalimantan would persist for the next several days," he added.
PARTICULATE POLLUTION
The transported smoke is contributing to higher concentrations of particulate matter, Bagtasa said, although local emissions remain an important source of pollution in Metro Manila.
Based on the Air Quality Index monitoring particulate matter 2.5 by the DENR Environmental Management Bureau on Monday morning, Las Piñas and Makati recorded “unhealthy” air quality, with AQI readings of 103 and 112, respectively.
Bagtasa said the transported smoke could be contributing to the elevated particulate matter readings, although local pollution is likely also playing a role.
He advised the public to minimize outdoor exposure when air pollution becomes visibly severe and to use masks as a mitigation measure.
“Kung tumaas talaga, kung talagang naging malabo iyong itsura sa labas because of air pollution, ang ano talaga is mag-mask (face mask) kung hindi maiwasan na lumabas, or to stay indoors,” he said.
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