Singapore’s air quality saw a significant improvement on October 22, as conditions returned to the good-to-moderate range after 18 consecutive days of unhealthy levels due to haze. By 3 p.m., the 24-hour Pollutant Standards Index (PSI) across the island varied between 71 and 99, enabling residents to safely engage in outdoor activities once more.
The western region of Singapore was the last to exit the unhealthy category, with its PSI dropping from 101 to 99. The unhealthy air quality period began on October 5, when PSI readings first exceeded the threshold of 101.
Throughout the island, fine particulate matter, or PM2.5, remained at normal levels, with one-hour PM2.5 readings ranging from 16 to 39 micrograms per cubic meter at the same afternoon hour.
Despite the notable improvement in Singapore’s air quality, regional haze remains a concern. Satellite data continues to reveal hotspots in Indonesia, although prevailing winds have so far diverted much of the smoke away from Singapore. Meanwhile, areas such as Peninsular Malaysia, Kalimantan, Sumatra, and western Sarawak are experiencing heavier pollution.
