Haze update Oct 4: Air quality improves slightly, 24-hour forecast in high-moderate to low-unhealthy range

Air quality in the Republic stayed in the moderate range on Sunday (Oct 4) afternoon, after 24-hour Pollutant Standards Index (PSI) readings in central Singapore exited unhealthy levels at 11am. At 6pm, PSI across Singapore ranged from 74 to 97, with central Singapore, with central Singapore recording the highest reading of 97.PSI readings between 51 to 100 denote the moderate range.Meanwhile, one-hour PM2.5 readings stayed in the normal band in the northern (48), southern (54) and western (42) regions, but readings in eastern (58) and central (83) Singapore are in the elevated band.In its daily haze situation update on Sunday evening, the National Environment Agency said the country’s 24-hour PSI is expected to be in the high-moderate to low-unhealthy range.It noted that moderate to dense smoke plumes from southern Sumatra have continued to drift towards Singapore and the surrounding region, while smoke haze was also observed from fires in Kalimantan.