After more than two weeks, the air was cleaner and views were clearer across Singapore on Friday (Oct 23).
At 6am, the PM2.5 readings – a gauge of the current air quality – were within the normal range, at 18 in the north, 26 in the south, 27 in the east, 53 in the west and 29 in central.
Only the west crossed into the elevated band at 56 at 10am, while the other regions remained in the normal zone.
Scores from zero 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 24-hour Pollutant Standards Index (PSI) at 10am were 66 in the north, 70 in the south, 72 in the east, 90 in the west and 79 in the central region.
This means air quality across Singapore has been in the good to moderate range – when normal activities can be carried out by everyone – for at least 24 hours. The west moved into this ideal category only at 3pm on Oct 22.
Since Oct 5, Singapore had been experiencing unhealthy air quality, denoted by 24-hour PSI readings above 101.
The 24-hour PSI, which is a rolling index of six key air pollutants, reflects air quality in Singapore over the past day.
When air quality breaches this threshold, people, especially the elderly, children and those with health issues, should start scaling down outdoor activities.
However, the National Environment Agency (NEA) has forecast that the air quality could worsen on Oct 23, with PSI levels forecast to range from 101 to 150.
While showers are forecast over Singapore and the surrounding region on Oct 23, dry conditions are expected over the southern parts of Sumatra and Kalimantan, it added.
Under prevailing south-easterly winds, smoke haze may be transported towards Singapore, NEA said.
Smoke haze from Sumatra may also drift towards Singapore on Oct 24 because of south-easterly or southerly winds, but rain should bring relief before clearer conditions return on Oct 25. THE STRAITS TIMES
