The air quality in Singapore entered the unhealthy range on Saturday (Oct 7), as authorities warned of hazy conditions due to a rise in the number of hotspots in Indonesia.
At of 10am, the 24-hour Pollutant Standards Index (PSI) for the eastern region of Singapore was 109. The National Environment Agency (NEA) regards a reading of 101-200 as “unhealthy”.
Readings in the other areas were in the moderate (51-100) range, with elevated readings in the central (93) and southern regions (83).
The one-hour PM2.5 readings showed elevated levels in the eastern (81), central (65) and southern (63) areas. A reading between 56 and 150 is considered elevated.
The agency forecast “slightly hazy” conditions for all of Saturday in the north, south, east and central parts of Singapore, with only the west experiencing party cloudy conditions.
NEA said late on Friday that air quality could enter the unhealthy range this weekend if forest fires persist in Indonesia, coupled with unfavourable wind direction.
The agency noted a “significant increase” in the number of hotspots in Sumatra, with 212 detected on Friday compared with 65 on Thursday and 15 on Wednesday.
“Smoke plumes and haze were observed from satellite imagery over southern and central Sumatra. A brief shift in the wind direction this afternoon, from southeasterly to southerly, blew some of the lighter haze toward Singapore and caused a deterioration in air quality,” it said in a media release.
“There is a likelihood of haze affecting Singapore over the coming weekend if the fires persist and winds direction is unfavourable.”
The 1-hour PM2.5 levels in the southern and eastern parts of Singapore had entered elevated levels – above 55 ug/m3 – on Friday afternoon and remained elevated at 10pm.
The agency added that it will begin providing daily haze advisories from Saturday evening.
The daily haze advisory will include the 24-hour PSI forecast, which can be used by the public in planning their activities and events for the next 24 hours.