Western Singapore’s 1-hour PM2.5 reading entered the “High” band for the first time this haze season on Wednesday (7 October), as air quality worsened across the island.
At 4pm, the 1-hour PM2.5 concentration in the west rose to 152, after recording 146 at 3pm. This was the first time the reading entered the “High” range during this year’s haze season.
The other four regions recorded readings between 91 and 121 at 4pm, which were in the elevated band.
Western Region Records Highest PSI Reading
The western region also recorded the highest 24-hour Pollutant Standards Index (PSI) reading among Singapore’s five regions at 135.
The central region recorded a PSI reading of 132, followed by the east at 128 and the south at 110. The northern region recorded a PSI reading of 104.
The 24-hour PSI measures average air quality over a longer period, while the 1-hour PM2.5 reading is meant to provide a more immediate indication of fine particle levels for outdoor activity decisions.
Haze Linked to Smoke Plumes From Region
The National Environment Agency (NEA) has said in recent haze updates that smoke plumes from southern Sumatra and parts of Kalimantan have been affecting Singapore.
On 6 October, NEA reported that moderate to dense smoke plumes from southern Sumatra and West Kalimantan were drifting towards Singapore, with dry conditions expected to continue in the affected areas.
NEA advises members of the public to check the 1-hour PM2.5 readings when planning immediate outdoor activities. When PM2.5 levels are elevated, healthy individuals should reduce strenuous outdoor activity, while vulnerable groups such as children, elderly people, pregnant women, and those with chronic lung or heart conditions should take additional precautions.
Haze Conditions Have Persisted Since September
Singapore’s haze situation has fluctuated since September, with air quality occasionally entering unhealthy levels.
On 29 September, all five regions recorded unhealthy 24-hour PSI readings, with the central region reaching 155 at one point.
The haze situation has been linked to dry conditions and smoke from fires in parts of Indonesia, with prevailing winds occasionally carrying the haze towards Singapore.
