Low chance of haze affecting Singapore despite increase in Sumatra hotspots

SINGAPORE: There is a low chance of haze affecting Singapore despite an increase in the number of hotspots detected in Sumatra. 

The National Environment Agency (NEA) said in its daily haze advisory on Tuesday (Oct 17) that the weather has remained dry over most parts of the surrounding region.

A total of 530 hotspots were detected in southern and central Sumatra, more than the 285 hotspots detected on Monday, added the agency. Smoke haze over southern and central Sumatra was also observed to be blown towards the northwest by prevailing winds.

"An increase in shower activities is forecast for Singapore and the surrounding region from tomorrow. The prevailing winds are forecast to blow mainly from the southeast or south, weakening to become light and variable in direction over the next few days.

"The likelihood of transboundary haze affecting Singapore is assessed to be low," said NEA. 

As of 6pm, the 1-hour PM2.5 concentration readings were in the normal range while the 24-hour Pollutant Standards Index (PSI) was 51 to 65 in the moderate range.

For the next 24 hours, the PSI for Singapore is forecast to be in the moderate range as well.

The skies have been mostly clear since Oct 7 when air quality fell into the unhealthy range for the first time since 2019.

Smoke from forest fires in central and Southern Sumatra was blown by winds towards Singapore on Oct 7 and Oct 8, which resulted in hazy conditions.

Rain over Singapore and the surrounding region last week lowered the likelihood of haze.

More showers are also forecast for southern Southeast Asia in the coming two weeks, which may improve the situation and reduce the chance of transboundary haze affecting Singapore.

"The chance of the 24-hour PSI reaching the unhealthy range in Singapore is low for the coming fortnight," the Meteorological Service Singapore (Met Service) said in its fortnightly weather advisory on Monday.