Haze persists on Monday as 24-hour PSI moves upwards in the unhealthy range

Haze situation at Sungei Buloh Wetland Reserve at 10.30am on Oct 19, 2015.
Haze situation at Sungei Buloh Wetland Reserve at 10.30am on Oct 19, 2015. ST PHOTO: YEO KAI WEN
Haze situation at Teban Gardens Road at 8am on Oct 19, 2015.
Haze situation at Teban Gardens Road at 8am on Oct 19, 2015.ST PHOTO: ONG WEE JIN

SINGAPORE - The haze continued to makes its comeback on Monday (Oct 19) as visibility deteriorated in most parts of Singapore.

Air quality also took a hit, with the 24-hour Pollutant Standards Index (PSI) remaining in the mid section of the unhealthy (101-200) band. But there was some improvement from noon, with the 24-hour PSI dipping slightly. 

The National Environment Agency (NEA) said the improvement was due to "a shift in the prevailing winds which helped to keep the denser haze from Sumatra away."

The total number of hotspots detected in Sumatra on Monday was 233, NEA said in its latest update. "Moderate to dense smoke haze is still persisting in parts of central and southern Sumatra. Some haze from Kalimantan is also observed to have spread to the sea areas southeast of Singapore," it said.
As of 11pm, the 24-hour PSI stood at 104-152. The three-hour PSI, which is not tied to a healthy advisory, increased to 209 from 96 at 9pm.

The conditions are expected to persist on Tuesday, with the 24-hr PSI is expected to be in the low to mid sections of the unhealthy range, the NEA said in its update on Monday evening.

"For tomorrow, the prevailing winds are forecast to blow from the southeast or south, and hazy conditions can still be expected. Reduced visibility is also expected if PM2.5 concentration levels are elevated," it said. PM2.5 refers to particles which are 2.5 microns or smaller.

But there was some good news from the Meteorological Service Singapore (MSS) on Sunday, which said Singaporeans may finally get some relief at the end of the month when the south-west monsoon season comes to an end.


According to the MSS, the inter-monsoon period that follows typically brings more rain, and light, variable winds. This will help to gradually ease the haze situation.

But the haze could still linger - experts said previously it could last till November - due to factors like the location and extent of fires in Sumatra and Kalimantan, direction of the prevailing winds and frequency of rain.

With air quality also at unhealthy levels in Malaysia, schools in the states of Malacca, Negeri Sembilan and Selangor have been ordered to close on Monday. Also told to shut were schools in several large districts such as Putrajaya and Kuala Lumpur.

On Sunday afternoon, hundreds of passengers were left stranded in airports when five flights on the Tawau-Kota Kinabalu route were cancelled.