Air quality in central Singapore improves as PSI drops

Since then, readings in the central, eastern and western parts of Singapore have occasionally crossed into the unhealthy range before dipping back into the moderate spectrum.

In an advisory on Sept 10, NEA said the 24-hour PSI is forecast to range from the higher end of the moderate category to the lower end of the unhealthy spectrum.

NEA said that it continues to observe moderate to dense smoke plumes from fires in southern and central Sumatra, as well as Kalimantan, adding that some haze also drifted towards Singapore.

It added that while “some showers are forecast mostly over northern and central Sumatra in the next few days… there is a risk of smoke haze affecting Singapore should the fires persist under the prevailing south-easterly or southerly winds”.

The recent developments mark the first time the PSI in Singapore hit unhealthy levels due to haze since October 2023.

Air quality is considered unhealthy when the PSI is in the range of 101 to 200, during which NEA advises the public to cut down on outdoor activities.

PSI readings of 51 to 100 are considered moderate, while values of 0 to 50 are in the “good” range.