Singapore wakes up to unhealthy air quality as 24-hour PSI hits 105 in the central region

Air quality in Singapore has slipped back to the unhealthy range again. After recording four days of moderate air quality, 24-hour Pollutant Standard Index (PSI) hit 102 in the central region at 11pm on Wednesday (Sept 9), and has continued into Thursday morning. At that time, 1-hour PM2.5 in both the central and western regions also reached the elevated range — at 83 and 57 respectively. Readings between 56 and 150 denote the elevated range. Meanwhile, 24-hour PSI for the central region remains in the unhealthy region at 105 at about 8.40am. It is in the moderate range for all other regions. 1-hour PM2.5 reading is in the normal range for all regions at that time.In its daily haze update on Wednesday evening, the National Environment Agency (NEA) had said that moderate to dense smoke plumes continue to be detected from fires in southern and central Sumatra and Kalimantan.