Singapore’s 24-hour Pollutant Standards Index is forecast at 101 to 190 for Monday 19 October, in the Unhealthy band. The forecast comes a day after the west recorded a season-high reading of 230.
As at 6pm on Sunday, the 24-hour PSI across Singapore sat at 109 to 192, still Unhealthy, while one-hour PM2.5 readings had eased to 36 to 69 micrograms per cubic metre. NEA credited the afternoon improvement to winds turning to blow from the south, though some Kalimantan smoke continued to drift in and smoke haze was also observed over Sumatra. The Monday band is the agency’s planning range for the next day’s outdoor activity, not a promise that every hour will sit at either end of it.
Monday and Tuesday wind shifts
Showers are expected over Singapore and the surrounding region on Monday. Winds from the south-southeast or south may limit the transport of Kalimantan smoke, but haze from Sumatra can still drift towards Singapore. On Tuesday, southeasterly or southerly winds and showers around the island could again cut the Kalimantan plume. From Tuesday night, though, winds are likely to turn east-southeasterly, which may bring Kalimantan fire smoke back overnight.
For a walk, commute or short errand, NEA points readers to live one-hour PM2.5 readings on haze.gov.sg and the myENV app, because the 24-hour PSI lags the air you are breathing now.
Why the west mattered on Sunday
The west spent Sunday morning in the Very Unhealthy band. Its 24-hour PSI hit 230 at 10am, the highest reading of this haze season and the year’s highest islandwide figure, before easing through the afternoon as the wind shifted. That spike lands on top of more than two weeks of Unhealthy air that has already forced outdoor event cancellations, postponed community gatherings and earlier ActiveSG closures.
NEA’s Sunday morning update had flagged widespread hotspots in Kalimantan and Sumatra, with moderate to dense smoke haze over parts of both islands and neighbouring areas. Extensive cloud cover still hid the full hotspot count from satellite.
How to use the numbers
Treat 101 to 190 as the planning band for longer outdoor plans on Monday. For immediate decisions, follow the hourly PM2.5 reading. The Ministry of Health’s haze advice remains that vulnerable people, including older adults, pregnant women and those with chronic heart or lung conditions, should avoid outdoor activity when hourly PM2.5 sits in the high band of 151 to 250. Healthy people should cut outdoor time when readings reach 251 or above. An N95 or equivalent mask can cut particle exposure for short outdoor trips; it is not generally needed for indoor spaces or a simple home-to-work commute.
Free N95 collection points and HazeMaskGoWhere remain active from earlier haze rounds. Updates continue on weather.gov.sg, nea.gov.sg, haze.gov.sg and myENV.
