Thick haze from Indonesian wildfires has blanketed large parts of Southeast Asia, forcing school closures in Malaysia, flight cancellations across the region, and prompting emergency health advisories in at least six countries. Philippine authorities declared Manila air quality acutely unhealthy on September 1, with the Pollution Control Department recording an Air Quality Index reading of 187, well above the 100-point threshold considered harmful to sensitive groups. Residents in Metro Manila were advised to remain indoors and wear N95 masks if venturing outside. The crisis, driven by slash-and-burn land clearing in Sumatra and Kalimantan provinces, has affected an estimated 25 million people across Indonesia, Malaysia, Singapore, Thailand, the Philippines, and Brunei, according to the Southeast Asian haze monitoring network. ## Fire Season Escalates Beyond Predictions Indonesian President Prabowo Subianto deployed 12,000 military personnel to combat the fires, which burned through 134,000 hectares of land between January and August 2026, according to data from the Ministry of Environment and Forestry. The figure represents a 40 percent increase over the same period in 2025. "The fires are concentrated in peatland areas that are extremely difficult to extinguish once ignited," said Heru Waluyo, director of fire prevention at the ministry. "Wind patterns are carrying the smoke northwest toward Malaysia and Singapore at speeds of 15 to 20 kilometers per hour." Malaysian Education Minister Fadhlina Sidek ordered temporary school closures in six states on the peninsula, affecting approximately 1.2 million students. The closures came after the Department of Environment recorded API readings above 200 in Johan Setra, Pahang, and Kuala Selangor. Singapore National Environment Agency issued a advisory urging residents to reduce outdoor activities, and the city-state recorded its worst haze conditions since the 2015 crisis that cost the region an estimated $16 billion in economic losses. ## Aviation and Trade Disrupted AirAsia Group cancelled 23 flights between September 1 and September 3, citing visibility below safe operating minimums at Kuching and Kota Kinabalu airports. Singapore Changi Airport reported delays averaging 45 minutes for regional departures. The haze has also disrupted palm oil production, the region largest agricultural export. Wilmar International, the world biggest palm oil trader, reported a 12 percent decline in fresh fruit bunch processing across its Sumatran mills during August. "The economic cost of the haze, including healthcare expenses, lost productivity, and agricultural damage, could exceed $4.6 billion this year," said Dr. Syed Mubarak, an environmental economist at the National University of Singapore. ## Regional Cooperation Tested The Association of Southeast Asian Nations established the Transboundary Haze Pollution Agreement in 2002, but enforcement mechanisms remain limited. Indonesia ratified the pact in 2014, yet satellite data from NASA Fire Information for Resource Management System shows fire hotspots in Riau and Jambi provinces continue to spike during dry seasons. Malaysian Prime Minister Anwar Ibrahim raised the issue directly with Prabowo during a bilateral call on August 31, urging Indonesia to accept international firefighting assistance. Indonesia has historically resisted external intervention, citing sovereignty concerns. The World Health Organization warned that prolonged exposure to haze at current concentrations increases the risk of respiratory infections, cardiovascular disease, and premature death, particularly among children under five and adults over 65. Hospitals in Kuala Lumpur reported a 35 percent surge in respiratory-related admissions during the last week of August.