Air quality in central Singapore returns to unhealthy range

Air quality in central Singapore returned to the unhealthy range on September 14, with the 24 hour Pollutant Standards Index (PSI) reaching 102 at noon. Readings in the other four regions of the city state ranged from 79 to 91. This follows a period of moderate readings that had persisted since September 11.

The National Environment Agency (NEA) reported that the dip in air quality is due to persisting hotspots and haze in parts of Indonesia, specifically in southern Sumatra and western, central, and southern Kalimantan. The NEA noted that dry conditions have been observed across the southern ASEAN region, though some showers occurred over parts of Sumatra. Smoke plumes from Kalimantan and southern Sumatra were observed drifting toward Singapore.

This event marks the first time since October 2023 that the PSI in Singapore has reached unhealthy levels. The PSI entered the unhealthy range previously on September 4, which prompted the NEA to begin providing daily haze advisories. The unhealthy PSI band is defined as 101 to 200, while readings between 51 and 100 are considered moderate.

Weather forecasts indicate that dry conditions are expected to persist over Kalimantan and central and southern Sumatra. With prevailing winds blowing from the south or south east, the NEA stated that there remains a risk of smoke haze affecting Singapore.