Smoke from Indonesian forest fires has drifted into Philippine skies, and the haze could linger for days as southwest monsoon winds keep carrying it north from Kalimantan.
What is happening
Dr. Gerry Bagtasa, an atmospheric physicist and professor of meteorology at the UP Institute of Environmental Science and Meteorology, said satellite imagery shows active fires in western and southern Kalimantan in recent days, with cross-equatorial winds transporting the smoke toward the Philippines.
The prevailing southwest monsoon, or Habagat, is doing much of the work. Normally, moisture and rain over the South China Sea wash pollutants out of the atmosphere before they arrive. This time the winds remain strong but there is less rain along the path, so the smoke has traveled largely uninterrupted.
Which areas are affected
Hazy conditions have been observed in Region IV-A (Calabarzon), portions of the Visayas, and possibly Zamboanga, according to Bagtasa. Cloud cover can make the haze harder to spot in some areas.
- Metro Manila: visibly hazier skies
- Region IV-A (Calabarzon)
- Parts of the Visayas
- Possibly Zamboanga
On Monday morning, the DENR Environmental Management Bureau’s air quality index monitor for fine particulate matter flagged two Metro Manila stations as unhealthy.
| Station | AQI reading (PM2.5) | Classification |
|---|---|---|
| Makati | 112 | Unhealthy |
| Las Piñas | 103 | Unhealthy |
The bigger regional picture
The Indonesian fires have ravaged tens of thousands of acres of land in Kalimantan and Sumatra, including ancient rainforest, part of a surge fueled by a super El Niño and a prolonged dry season. The smoke has already pushed Kuala Lumpur to briefly rank as the most polluted city on Earth and forced hundreds of schools to close in Malaysia, while Singapore went on alert.
Indonesia has responded by intensifying its firefighting operations, deploying more than 24,000 ground personnel and water-bombing aircraft, and police have arrested 72 people suspected of starting fires. Authorities blame slash-and-burn land clearing, which Indonesia is the world’s largest producer of palm oil, for much of the burning.
When could it clear
Bagtasa said the hazy conditions could persist for the next several days, though rain is forecast by Wednesday or Thursday over the West Philippine Sea that could scrub the skies before the smoke reaches land. The movement of weather systems north of the country, interacting through the Fujiwhara effect, could prolong the winds carrying the haze until at least the end of the week.
How to stay safe
Bagtasa advised the public to minimize outdoor exposure when air pollution is visibly severe, to wear a mask when going out is unavoidable, and to stay indoors. The elevated particulate readings add to a season that has already seen a very strong El Niño forecast and weather-driven Habagat class suspensions in recent days.
