On Monday, 5 October, the 24-hour PSI was in the unhealthy range (101 to 200) in all regions of Singapore, according to CNA and the Straits Times. The Straits Times had reported earlier that air quality fell back into the unhealthy range overnight. On Sunday morning only the central region was unhealthy, at 102. NEA forecast Tuesday's 24-hour PSI in the high moderate to mid unhealthy range, as winds were expected from the south-east or east-south-east. The smoke comes from fires in southern Sumatra and Kalimantan. Regional forecasters expect strong El Niño conditions and below-normal rainfall until November. The current episode began with the first unhealthy reading since 2023 on 4 September.
Haze is a health problem first, and a cost to the economy second: lost working days, hospital visits, cancelled outdoor events and lost tourist spending. A long, dry El Niño season means the episode may not end soon. CNA's explainer on regional losses shows why the issue keeps returning to ASEAN's agenda.
Check the 24-hour PSI and the one-hour PM2.5 reading before exercise. If you are older, pregnant, or have heart or lung conditions, keep outdoor activity to a minimum on unhealthy days. Keep windows closed and consider an air purifier for the room where you sleep.
Prevention is working better than in 2015 and 2019, and this year's haze is mainly the result of an unusually dry El Niño season that no government can control.
Regional commitments still depend on enforcement on the ground. Until companies that clear land by fire face real penalties, haze will return every dry year.
Watch two things this week: whether NEA's forecast moves into the mid unhealthy range on Tuesday, and whether race organisers announce any changes to outdoor events. A wind shift could bring relief within days, but a dry October could keep the haze with us until the monsoon. Our advice is plain: plan outdoor exercise for the morning check, not by habit.
CNA, The Straits Times (5 Oct 2026) · NEA forecast as reported · ASEAN Specialised Meteorological Centre outlook as reported
Haze pushes air quality into the unhealthy range across Singapore. NEA expects no quick relief on Tuesday
The 24-hour PSI crossed 101 in every region on Monday, a month after the first unhealthy readings since 2023. Smoke from fires in Sumatra and Kalimantan is drifting in on south-easterly winds.
Singapore spent Monday under a grey sky. The Straits Times reported that air quality fell back into the unhealthy range overnight, and by the afternoon both CNA and the Straits Times said the 24-hour PSI was in the unhealthy band in all regions of the island. The PSI is a rolling 24-hour average of six pollutants, and readings from 101 to 200 count as unhealthy. On Sunday morning only the central region had crossed that line, at 102. The spread to every region on Monday marks the worst day of the current episode so far.
The National Environment Agency forecast that Tuesday's 24-hour PSI would sit between the high moderate and mid unhealthy range, because winds were expected to keep blowing from the south-east or east-south-east. That direction carries smoke from land and forest fires in southern Sumatra and Kalimantan. Regional weather forecasters have warned of strong El Niño conditions and below-normal rainfall over much of South-east Asia from September to November, which keeps peatland dry and makes fires harder to put out.
This is not a short spell. Singapore first slipped into the unhealthy range on 4 September, for the first time since 2023, and the haze has come and gone since then. CNA published an explainer on Monday on the billions of dollars the region has lost to past haze episodes, and on why prevention efforts across South-east Asia keep falling short. The same pattern is showing up elsewhere: the Straits Times reported that Myanmar has warned of power cuts linked to El Niño.
For most people the practical question is simple: whether to go outside. NEA's standing advice for the unhealthy range is for healthy people to cut down on prolonged or strenuous outdoor exercise, and for the elderly, pregnant women and children to keep such activity to a minimum. People with chronic lung or heart conditions are told to avoid it. The timing is awkward for the city's busiest sporting week: the Formula One race weekend arrives later this week, and outdoor fan events are already under way. Organisers have not announced any changes. DailyDrop will watch the morning PSI and NEA's three-day outlook.
Some things remain unclear. We could not confirm an official count of fire hotspots in Indonesia for Monday, and figures circulating online appear to come from earlier haze years, so we have left them out. Nor is there yet an estimate of what this episode is costing Singapore. What is clear is the pattern of the past month: readings rise when the wind turns south-easterly and ease when it shifts. That makes the wind forecast, more than any single day's reading, the best guide to the week ahead. Until the inter-monsoon rains arrive in earnest, hazy days are likely to recur.