The 2026 Southeast Asian haze crisis is a large air pollution crisis and the current continuous transboundary haze season that affected several countries in Southeast Asia since 1 August 2026, including Brunei, Indonesia, Malaysia, Philippines, Thailand, Singapore and Vietnam.
Background and causes
The haze is attributed to the ongoing 2026 Indonesia wildfires, particularly fires in parts of Sumatra and Kalimantan. The forecasted "super" El Niño also intensifies drought and wildfire haze spread, challenging wildfire reduction. Moreover, positive Indian Ocean Dipole (IOD) amplifies the risk of wildfire and haze. Combination both El Niño and positive IOD causes drier ground cover and adds the risk for severe fires in September–October. During periods of dry weather, vegetation and peatlands become highly susceptible to fire. Smoke and fine particulate matter generated by these fires can be transported by prevailing winds across national borders, affecting air quality in neighbouring countries such as Malaysia and Singapore.
Affected countries Indonesia
In West Kalimantan the worsening conditions are being closely watched from Sarawak, given the proximity of the two regions and the potential for haze to be carried across the border by prevailing winds.
Malaysia
The government of Sarawak, in response to the rising API levels, activated its Sarawak State Disaster Management Committee (SDMC or JPBNS) to monitor air quality and issue protective measures for its citizens, including face mask mandates and the cancellation or closure of events and public buildings.
On August 21, Sarawak continued to experience the second wave of transboundary haze season, with Serian surging the highest Air Pollutant Index (API) reading in Sarawak at 242, placing the area in the "Very Unhealthy" category. The SDMC data showed eight other areas in Sarawak recording the unhealthy air quality, underscoring the widening impact of the transboundary haze. These affected areas were Serian at 191, Lubok Antu (189), Kuching (188), Sri Aman and Lundu (178), Samarahan (171), Tebedu (164), Sarikei (153), and Sibu (125).
The SDMC said that they were closely monitoring weather conditions, air quality, hotspots, the risk of forest and peatland fires, and the status of the state's water supply was continuing in coordination with relevant agencies. The intensified monitoring reflects growing concern over the wider environmental and public health risks posed by the worsening haze, particularly in areas close to the Indonesian border.
On August 29, Serian recorded a hazardous air quality (302). The condition worsens, and on 4 September, Yang di-Pertuan Agong, Sultan Ibrahim, with advice from Prime Minister Anwar Ibrahim and Sarawak Premier Abang Johari Openg, declares emergency after the AQI reaches over 500. Cloud seeding operations have been approved in affected areas to mitigate the air quality issues and supplement the area's available water resources.
On September 18, according to Environment Department's Air Pollutant Index Management System (APIMS), 34 of 68 stations nationwide recording unsafe levels, with several regions edging dangerously close to the "Very Unhealthy" level. Johan Setia in Selangor recorded the nation's worst air quality at 198, followed closely by Kuching (192) and Samarahan (184) in Sarawak. Heavy haze also gripped Peninsular Malaysia, with Nilai logging a reading of 181, Seri Manjung at 176, Putrajaya at 173, and both Shah Alam and Seremban at 171. In Sarawak, Serian also recorded an unhealthy reading of 180. Out of 68 stations nationwide, only three logged "Good" air quality, all located in East Malaysia: Limbang, Sarawak (49); Sandakan, Sabah (46); and Kota Kinabalu, Sabah (44). Air quality plummets to unhealthy levels across half of Malaysia as of 8am
On 7 October, the government of Johor announced that all schools in the state will be closed for the next two days due to the worsening air quality, with Batu Pahat recording the highest API at 203 the night before, placing it at the very unhealthy range (201-300).
Brunei Darussalam
The Department of Environment, Parks and Recreation under the Ministry of Development on 31 August at 11 am recorded 94 pollutant standard index (PSI) for Brunei-Muara, 79 at Tutong, 95 at Belait and 69 at Temburong which was considered in the 'moderate' category (51 PSI - 100 PSI).
On 1 September at 4 pm, after taking account of both particulate matter (PM10) and particulate matter 2.5 (PM2.5), readings from two districts were categorized in the 'Very unhealthy' category (201 PSI - 300 PSI). Brunei-Muara recorded 215 PSI, 168 at Tutong, 211 at Belait and 164 at Temburong. A 2026–27 Malaysia FA Cup home fixture between DPMM FC and Terengganu FC on this date was postponed due to the worsening conditions.
The Ministry of Education and Ministry of Religious Affairs are advising all government and private institutions to implement a Home-Based Learning (HBL) from 2 to 3 September.
Singapore
In May 2026, the National Environment Agency (NEA) and Meteorological Service Singapore (MSS) warned that there is an increased likelihood that Singapore could experience haze from June to October due to the effects of El Niño–Southern Oscillation and the Indian Ocean Dipole.
On 4 September at 7 am, the Central Region entered the Unhealthy range (100 - 200 PSI) with a PSI of 101. This was the first time since October 2023 that the PSI hit the 'Unhealthy' category. At 9 pm, the Eastern Region recorded a PSI of 102, the Central Region recorded a PSI of 120, categorizing both in the 'Unhealthy' category, while the Western Region recorded a PSI of 97, the Northern Region 86, and the Southern Region 85, placing all three in the 'Moderate' category (51 - 100 PSI).
The Haze Task Force announced on 4 September that should the PSI enter the 'Very Unhealthy' category (201 - 300 PSI), air-conditioned rooms in all community centres (CCs) and selected residents’ committees (RCs) will be on standby. The NEA also announced that it would begin providing daily haze advisories from the evening of September 4, and will include the additional 24-hour PSI forecast.
On 5 September around midnight, the Western Region recorded a PSI of 101, categorizing it in the 'Unhealthy' category (100 - 200 PSI). At 7 am, the Western Region recorded a PSI of 102, and the Central Region 119, placing both in the 'Unhealthy' category, while the Eastern Region recorded a PSI of 99, the Northern Region 85, and the Southern Region 88, placing all three in the 'Moderate' category.
On 14 September at 4 pm, the Central Region recorded a PSI of 115, while the West and East regions both recorded a PSI of 102, placing all three regions in the 'Unhealthy' category. The North and South regions recorded a PSI of 87 and 91, respectively, placing both regions in the 'Moderate' category. By the morning of 15 September, all five regions were in the unhealthy range, which was the first time it has happened since September 2019, with the Northern Region recording a PSI of 104 at 6 am. However, air quality improved as the day progressed, with the Southern and Northern region going back into the moderate range by 1pm. By the midnight of 16 September, the air quality for the Eastern and Western region went back to moderate range, and the Central region doing so at 11am.
On the evening of 17 September, the air quality in the Central region briefly went back to unhealthy levels as prevailing winds blew from southeast to southwest on that day. Air quality returned to normal levels and continued to improve on 18 September. However, the Central region went back to the unhealthy range on 19 September at 1pm.
PSI readings went back to the unhealthy range on 26 September in the Central region, and 27 September in the Eastern and Western regions. This is after the air quality had seen improvements in the previous few days as a result of rain in the country.
The PSI of the Central region started climbing on the afternoon and evening of 4 October, before entering the unhealthy range overnight on 5 October, with the Western regions also entering the unhealthy range later in the morning. By the midnight of 6 October, all regions entered the unhealthy range, with a PSI range of 102 to 135 as of 5 pm, though the air quality at the Southern region dipped to moderate levels at 8pm.
At 4 pm on 7 October, with a 1-hour PM 2.5 reading of 152, the Western region entered the high range (151-250) for the first time in this haze season. The Western region went back to the elevated range an hour later, though the 24-hour PSI across all five regions remained at the unhealthy range. The haze situation may worsen on 8 October, with the PSI forecast set to be entirely in the unhealthy range.
Philippines In early September 2026, the haze had reached and affected air quality across several parts of the Philippines after smoke from fires in Kalimantan, Indonesia was carried by prevailing monsoon winds. Metro Manila, Calabarzon and Mimaropa were among the affected areas, with several cities recording very unhealthy to acutely unhealthy air quality levels. In Quezon City, face-to-face classes in public schools were suspended due to hazardous air pollution, while similar suspensions were implemented in parts of Metro Cebu as the haze persisted.
Authorities advised residents to limit outdoor exposure and wear properly fitted particulate masks, such as N95 or KN95 masks, particularly in areas with unhealthy air quality. The haze also affected parts of the Visayas and Mindanao, including Iloilo, Cebu and Zamboanga City, highlighting the wide geographical reach of the transboundary pollution.
Vietnam On 14 September, the haze reached southern Vietnam as the winds over the southern ASEAN region were forecasted to blow mainly from the southeast.
Impacts Cancellations of outdoor activities and events Several outdoor activities and events in Kuching, Samarahan, and Serian have been postponed or delayed due to the ongoing haze season in Sarawak. This including 53rd Sarawak Schools Sports Council (MSS Sarawak) Athletics Championship 2026 which is actually scheduled and take place on August 10 until August 14, but postponed due to unhealthy air quality in Samarahan. Sarawak Education Department (Jabatan Pendidikan Sarawak) also reminded to all district education offices (Pejabat Pendidikan Daerah) and all educational institutions under its purview to take seriously preventive measures to safeguard students and school staff during hot weather and haze conditions.
On August 19, Deputy Minister in the Sarawak Premier's Department, Datuk Dr. Abdul Rahman Junaidi, said the 2026 Sarawak-level Maulidur Rasul celebration, will be held at Dewan Sentral Sarikei on August 25, which is will feature only a gathering, without a procession due to the unhealthy haze situation and hot weather. This Maulidur Rasul celebration was originally to be scheduled and take place at the Sarikei Sports Complex, but the venue and programme were changed as a precautionary measure.
Closure of schools and education institutions On August 12, Sarawak government announced a total of 108 schools in Serian area have been closed after the air pollutant index (API) exceeded over 200. Deputy Premier of Sarawak, Datuk Amar Douglas Uggah Embas said this solution was in line with the National Haze Action Plan (Pelan Tindakan Jerebu Kebangsaan), which allowed the immediate closure of all schools, kindergartens and childcare centres once the API breaches 200 and above. At the same time, it is also as the precautionary solutions to protect the safety, health and well-being of all students and school staff in Serian. To ensure the continuous learning for the students, home-based teaching and learning (PdPR) will be implemented during the closure period.