Singapore’s air quality remained in the moderate range on Sept. 23, with showers expected to help reduce the immediate risk of smoke haze even as dry conditions persisted over parts of Sumatra and Kalimantan.
At 7pm on Wednesday, the 24-hour Pollutant Standards Index (PSI) ranged from 58 to 67 across Singapore, with the western region recording the highest reading. The one-hour PM2.5 reading was within the normal band in most areas, although the western region recorded an elevated reading of 58.
The National Environment Agency (NEA) forecast the 24-hour PSI for Sept. 24 to range from moderate to low-unhealthy levels. However, showers were expected over Singapore and surrounding areas, potentially lowering the risk of smoke haze affecting the island.
The regional haze risk remains linked to persistent dry weather and fires in southern Sumatra and parts of Kalimantan. Moderate to dense smoke plumes were observed in those areas, while the number of detected hotspots in Kalimantan rose to 304 on Sept. 22 from 198 a day earlier, according to regional monitoring data cited by the NEA.
Singapore has experienced fluctuating air quality throughout September, with some regions previously crossing into the unhealthy range. The 24-hour PSI is considered moderate at 51 to 100 and unhealthy from 101 to 200.
The NEA advises residents to use the one-hour PM2.5 reading when deciding whether to undertake immediate outdoor activities, while the 24-hour PSI forecast is intended to help people plan activities for the following day.
For Sept. 24, the expected showers could provide temporary relief, but continued fires and dry conditions in parts of the region mean haze conditions can still change quickly. Residents are therefore advised to monitor the latest air-quality readings and health advisories before planning prolonged or strenuous outdoor activities.
