Singapore’s central region recorded unhealthy air quality again on Thursday evening (17 September), with the 24-hour Pollutant Standards Index (PSI) crossing above the unhealthy threshold.
The PSI reading in the central region reached 102 at 9pm and stood at 103 at 11pm, according to the National Environment Agency (NEA). The other regions remained in the moderate range.
Haze From Regional Fires Continues To Affect Singapore
The unhealthy PSI range is between 101 and 200. A reading between 201 and 300 is considered very unhealthy, while readings above 300 are hazardous.
NEA said in its haze advisory that prevailing winds from the southeast to southwest had brought some smoke haze from southern and central Sumatra towards Singapore. Smoke plumes were also observed over southwestern Kalimantan.
Dry conditions are expected to continue over parts of southern Sumatra and southern Kalimantan. NEA said there remains a risk of smoke haze affecting Singapore if fires in the region persist.
Air Quality Has Fluctuated Between Moderate And Unhealthy
Singapore’s air quality has moved in and out of the unhealthy range over the past two weeks.
The PSI in the central region first crossed into the unhealthy range on 4 September, the first time since 2023. NEA began issuing daily haze advisories from that evening.
On 15 September, all five regions in Singapore recorded unhealthy air quality levels for the first time since September 2019. The central region’s PSI reached 154 at 6am that day.
NEA advises members of the public to refer to the 1-hour PM2.5 readings for immediate outdoor activity decisions and the 24-hour PSI forecast when planning activities for the following day.
For healthy people, prolonged or strenuous outdoor activities should be reduced when the PSI is in the unhealthy range. Vulnerable groups, including elderly people, children, pregnant women and those with chronic lung or heart conditions, should minimise or avoid such activities.
