Haze in Singapore: Air quality improves but most regions remain in unhealthy band

SINGAPORE - The haze situation improved overnight on Oct 19, with the 24-hour PSI readings falling across the board, although in four of the five regions, the pollution levels were still classified as unhealthy.

At 6am, the Pollutant Standards Index (PSI) stood at 92 in the north, 104 in the south, 107 in the east, 139 in the west and 117 in the central region.

This is a marked improvement from the day before, when the 6am readings reached significantly higher levels: north (129), south (172), east (181), west (227) and central (185).

It also hit a new season high of 230 in the west at 10am, placing it in the “very unhealthy” band.

Meanwhile, one-hour PM2.5 readings – which measured in micrograms per cubic metre and are a gauge of the current air quality – hovered between the normal and elevated bands on Oct 19.

At 6am, the readings were: north (40), south (60), east (68), west (75) and central (75).

PM2.5 scores from 0 to 55 represent normal values, those between 56 and 150 indicate an elevated concentration of fine particles, while readings between 151 and 250 are considered high and scores above 251 are classified as very high.

The highest PM2.5 reading this haze season was recorded at 3pm on Oct 14 in the western part of the island at 288.

On Oct 18, the National Environment Agency (NEA) had forecast for Oct 19 that the PSI would lie between 101 and 190 – in the unhealthy band.

Rain is forecast over Singapore and the surrounding region on Oct 19, while winds are expected to blow from the south-south-east or south, which may limit the transport of smoke haze from Kalimantan to Singapore.

However, some smoke haze from Sumatra may drift towards Singapore, NEA added.

The haze situation on Oct 19 marks a relative easing compared to the situation last week, when PSI readings remained in the unhealthy or very unhealthy bands on most days. On Oct 16, three in five regions recorded very unhealthy PSI levels.

Singapore is currently experiencing its 15th day of unhealthy air – the longest stretch since the 2015 haze crisis, during which bad air persisted for 14 days from Sept 23 to Oct 7.