Haze in Singapore: Normal PM2.5 and good to moderate 24-hour PSI readings islandwide

SINGAPORE – The air quality here has remained healthy overnight, with the hourly PM2.5 readings remaining in the normal range and the 24-hour PSI in the good-to-moderate band across the island.

At 6am on Oct 27, the one-hour PM2.5 readings in all the five regions of Singapore ranged between 14 and 32, while the 24-hour PSI stood between 62 and 72.

PM2.5 readings are gauged hourly and reflect the current air quality. Scores from zero to 55 represent normal values, and those between 56 and 150 indicate an elevated concentration of fine particles.

Air quality is considered good to moderate when the PSI – a 24-hour rolling average of six key air pollutants – is in the range of zero to 100, and unhealthy when it is in the range of 101 to 200.

When air quality breaches the “unhealthy” threshold, people, especially the elderly, children and those with health issues, should start scaling down outdoor activities.

Following weeks of bad air quality, residents in Singapore saw some respite over the weekend when the PM2.5 levels stood in the normal range for most parts of the country although the 24-hour PSI readings remained unhealthy in some areas.

Forecast for Oct 27

In its daily haze advisory on the evening of Oct 26, the National Environment Agency (NEA) said the PSI for Oct 27 is forecast to be in the good-to-moderate range of 60 to 90.

Smoke haze was observed but confined over Kalimantan on Oct 26, NEA said, adding that it was cloudy over Singapore.

NEA said the likelihood of smoke haze affecting the Republic on Oct 27 is low as prevailing winds are expected to blow from the north-east or south-east. Showers are also expected over and in the vicinity of Singapore.

For Oct 28 and 29, winds are forecast to become variable and showers are expected over Singapore and in the surrounding region.

“The wet conditions should help keep hotspot and smoke haze activity suppressed,” NEA said.