Air quality across Indonesia, Malaysia, Singapore and Brunei has fallen to hazardous levels this month, as peatland and forest fires burning across seven Indonesian provinces send haze over neighbouring countries. Central Kalimantan recorded an air pollution index reading of 1,919 on 2 September, far beyond the threshold of 300 that authorities classify as hazardous.
Singapore recorded unhealthy air quality across all regions of the city-state for the first time since 2019. Some 40 of 68 monitored areas in Malaysia registered unhealthy readings by mid-September. All four districts of Brunei fell into the unhealthy range as well, making this one of the most widespread haze events the region has faced in several years.
Emergency measures in Sarawak
Malaysia declared a state of emergency in parts of Sarawak, closing 647 schools across 12 districts and shifting roughly 200,000 students to home-based learning. The scale of the closures reflects both the severity of the haze and growing caution around prolonged exposure among children. Children accounted for nearly a quarter of the 113,336 respiratory infection cases recorded across the affected Indonesian provinces by 9 September.
Indonesian officials say the fires are linked to land-clearing practices that have combined with drought conditions to spread faster and burn longer than usual. The fires burned 202,000 hectares between January and July, before accelerating sharply to 600,000 hectares in August alone. President Prabowo Subianto has called for stricter penalties against those responsible. Authorities are investigating 112 people over suspected fire-setting, whether deliberate or accidental, and five companies have had their operating licences suspended pending the inquiries.
Japan has sent three CH-47 Chinook helicopters to help with firefighting, adding to Indonesia’s own aerial response as ground crews struggle to contain fires across difficult peatland terrain. Peat fires burn differently from ordinary forest fires. They smoulder underground for weeks, resist water drops that work on surface blazes, and can reignite well after visible flames appear to have been brought under control. That behaviour helps explain why this year’s haze season has proven so difficult to shorten, despite the aerial support now in place.
An El Nino link running through the region
Meteorologists attribute the severity of this year’s haze season to a developing “super” El Nino, which has left Sumatra and Kalimantan drier than usual and made peat fires markedly harder to control than in a typical year. The same weather pattern is shaping farm policy well beyond Southeast Asia. Colombia’s government moved this week to freeze agricultural credit ahead of a similarly forecast El Nino event, betting that early action will do more good than a response mounted after losses appear.
Cities elsewhere are making comparable bets on early intervention. Lagos state officials have been pressing international partners for climate financing to fund resilience measures before, rather than after, the next flood or heat event strikes. Southeast Asia’s haze crisis offers a case study in what happens when that kind of preparation runs out of time. Once fires are burning across peatland this extensive, suppression becomes a matter of managing the damage rather than preventing it.
For the millions of people breathing hazardous air across four countries this month, the immediate relief will likely come only when seasonal rains return, rather than from firefighting efforts alone. Regional governments have discussed longer-term measures, including tighter enforcement against land-clearing by fire and expanded peatland restoration. Those steps take years to show results even when funded and implemented promptly. In the meantime, schools, businesses and hospitals across the affected region are absorbing costs that fall well outside any single country’s fire-suppression budget.
