Despite the elevated 24-hour PSI, hourly PM2.5 concentrations returned to the “normal” band across all five regions during the morning. At 10am, hourly PM2.5 readings ranged from 31 to 48 micrograms per cubic meter. NEA defines PM2.5 readings between 0 and 55 as normal, while concentrations between 56 and 150 indicate elevated levels. By noon, hourly PM2.5 readings ranged from 16 to 42, confirming that immediate air quality had improved from the previous day, even as the rolling 24-hour average remained high.
The current haze episode began to deteriorate on Oct 24, following a brief period of “good to moderate” air quality on Oct 23. On Saturday (Oct 24), air quality worsened overnight, with the 24-hour PSI reaching the unhealthy range across all five regions. At 3pm on Oct 24, PSI readings ranged from 111 to 152, with the highest levels recorded in the west. NEA confirmed that smoke haze was observed drifting from Sumatra towards Singapore, with fires also visible over Kalimantan. The agency noted that Singapore has stepped up action regarding the Kalimantan fires, targeting three additional firms for enforcement.
NEA attributes the persistence of the haze to wind patterns and meteorological conditions. In its evening advisory on Oct 24, the agency forecasted that the 24-hour PSI for Sunday would range from 80 to 130. The agency stated that winds are expected to blow from the southwest or west on both Sunday (Oct 25) and Monday (Oct 26). This direction is expected to limit the transport of smoke haze into Singapore. Additionally, showers are forecast over Singapore and the surrounding region, which NEA said would likely help improve haze conditions.
The agency issued health advisories for Sunday, recommending that healthy individuals reduce prolonged or strenuous outdoor physical exertion. Vulnerable groups, including children, the elderly, pregnant women, and those with chronic heart or lung conditions, were advised to minimize strenuous outdoor activities. NEA advised the public to consult the 24-hour PSI forecast for planning outdoor activities and to check the latest one-hour PM2.5 readings before immediate outdoor exertion, particularly if hourly concentrations are in the elevated band.
Looking ahead, NEA expects the haze situation to improve by Tuesday (Oct 27). Winds are projected to continue blowing from the southwest or west on Oct 26 and 27, and continued rainfall in the region is expected to further mitigate the smoke haze. The agency maintains that the combination of limited smoke transport and local showers will facilitate a return to better air quality in the coming days.
