SINGAPORE, Oct 18 — Singapore’s western region recorded a season-high Pollutant Standards Index (PSI) reading of 230 at 10am today, as the island endured its 14th consecutive day of unhealthy air quality.
The Straits Times (ST) reported that the reading placed the west in the “very unhealthy” category, while the rest of the island remained in the “unhealthy” range, with PSI readings between 130 and 187.
Singapore has experienced continuous unhealthy air quality since October 5, marking its longest stretch of poor air quality since the 2015 haze crisis, when the country endured 14 consecutive days of bad air from September 23 to October 7.
The PSI measures six key air pollutants using a 24-hour rolling average. Readings between 101 and 200 are classified as unhealthy, while those between 201 and 300 are considered very unhealthy, according to the report.
ST reported that one-hour PM2.5 readings, which measure fine particulate matter in micrograms per cubic metre, were elevated across all five regions at 10am.
The readings were 72 in the north, 82 in the south, 71 in the east, 139 in the west and 117 in the central region.
PM2.5 readings between zero and 55 are considered normal, while those between 56 and 150 indicate elevated concentrations. Readings between 151 and 250 are classified as high, while those above 251 are considered very high.
According to the English daily, the highest PM2.5 reading recorded so far this year was 288 in the western region at 3pm on October 14.
In its daily haze advisory on the evening of October 17, Singapore’s National Environment Agency (NEA) forecast that the PSI could range between 150 and 220, spanning the unhealthy and very unhealthy categories.
Showers were expected across Singapore and the surrounding region today, potentially offering some relief from the haze.
NEA said winds were forecast to shift to blow from the south-south-east or south, potentially reducing the transport of smoke haze from Kalimantan to Singapore.
However, some smoke haze from Sumatra could drift towards the island, the report said.
More showers were forecast over Singapore and parts of Kalimantan on October 19 and 20.
The agency added that winds were expected to gradually weaken and blow from the south-east or south, which could further reduce the movement of smoke haze from Kalimantan towards Singapore.