Several areas in Sarawak and Selangor recorded unhealthy and very unhealthy Air Pollutant Index (API) readings throughout August 2026, prompting health advisories and school closures. The haze was caused by transboundary pollution, according to authorities [1, 2, 3, 4, 5, 6, 7, 8].
In Sarawak, districts including Serian, Kuching, Samarahan, Sri Aman, Sarikei, Mukah, Sibu, and Bintulu frequently registered API values exceeding 100, indicating unhealthy air quality [1, 2, 3, 4, 7, 8]. Serian district recorded the highest and most hazardous readings, with an API reaching 241 on August 21, marking very unhealthy conditions [8].
In Selangor, Johan Setia consistently reported unhealthy air quality, with API readings ranging from 150 to 160 between August 12 and 18 [1, 4, 5, 9, 6]. On August 18, Johan Setia’s API hit 160 at 10 a.m., maintaining persistent haze levels [6].
The poor air quality forced over 100 schools to close temporarily in the Serian area after API readings topped 200 early in August. A total of 108 schools switched to home-based learning to reduce exposure to the polluted atmosphere [2, 10]. On August 20, schools across six Sarawak districts—including Kuching, Padawan, Serian, Samarahan, Bau, Lundu, Sri Aman, and Lubok Antu—were ordered closed for two days due to unhealthy haze, with Serian recording an API of 193 and Kuching 190 [10].
The Sarawak State Disaster Management Committee said, "Under the National Haze Action Plan, which falls under the jurisdiction of the Sarawak State Education Department director, schools, kindergartens and nurseries will be closed immediately once the API reaches 200" [2]. The Sarawak State Education Department added the closures are a "precautionary measure to protect the safety, health and welfare of students and school staff" [10].
Nationwide, schools may close at principals’ discretion if API levels exceed 200. Deputy Education Minister Wong Kah Woh stated, "If API readings exceed 100, schools must suspend outdoor activities and gatherings. Outdoor sports events should also be postponed" [11]. The Health Ministry advised the public to reduce outdoor activities and wear face masks when API surpasses 100, especially for vulnerable groups like children, the elderly, and those with chronic illnesses [1, 2].
API readings are compiled hourly from 68 air quality monitoring stations across Malaysia. The index categories range from 0-50 as good, 51-100 moderate, 101-200 unhealthy, 201-300 very unhealthy, and above 300 hazardous [1, 2, 3, 4, 5, 6, 7, 8].
On August 12, the Health Ministry strengthened surveillance of haze-related illnesses after 10 stations (9 in Sarawak, 1 in Selangor) recorded unhealthy API readings. That same day, 108 schools in Serian closed as API exceeded 200 [1, 2]. The closures on August 20-21 affected multiple districts, as continued haze elevated API values above unhealthy thresholds [10]. Authorities remain monitoring the air quality closely.
