Haze in Singapore: PSI forecast to remain in unhealthy to high unhealthy range

SINGAPORE – The 24-hour Pollutant Standards Index (PSI) for Oct 11 is forecast to be in the “unhealthy to high unhealthy range”, staying out of the “very unhealthy” range of 201 to 300.

In the National Environment Agency’s (NEA) daily advisory issued at 7pm on Oct 10, the agency noted: “Moderate to dense smoke haze from southern Sumatra was observed to drift towards Singapore. Smoke haze was also observed in many parts of Kalimantan.”

It added that the haze will continue to drift towards Singapore under prevailing east-south-easterly or southerlywinds.

This marks a slight improvement from the previous day, when NEA forecasted an “unhealthy to low very unhealthy range”.

As at 7pm on Oct 10, however, the PSI reading had not entered the “very unhealthy” band. Readings on the day peaked at 183 in the central region, with the reading in the region being 168 at 7pm.

In other regions, the 24-hour PSI readings also hovered at unhealthy levels, measuring 118 in the north, 128 in the south, 150 in the east and 152 in the west.

The haze stems from forest and land fires in Sumatra and Kalimantan, largely driven by the use of fire to clear land for agriculture.

Fuelled by the ongoing El Nino, these dried-out peatlands can burn for weeks once ignited and are notoriously difficult to put out.

Reduce outdoor physical activities

Air quality is considered unhealthy when the PSI – a 24-hour rolling average of six key air pollutants – is in the range of 101 to 200.

Under unhealthy 24-hour PSI readings, healthy individuals should reduce prolonged or strenuous outdoor physical activities, according to the haze advisory.

Vulnerable people – including the elderly, pregnant women, children and those with chronic lung or heart disease – should minimise or avoid such activities entirely.

The PSI reached a peak for 2026 on Oct 9, reaching 192 in the central region between 5pm and 8pm.

Meanwhile, the PM2.5 readings remained in the elevated band across the island as at 7pm, registering 63 in the north, 72 in the south, 73 in the east, 98 in the west and 107 in the central.

The reading in the central region briefly crossed into the “high” band at 151 at 3pm, before easing back to 142 in the elevated band by 4pm.

An hourly PM2.5 reading – used to plan for activities within the next hour – between 56 and 150 indicates an elevated concentration of fine particles, while that between 151 and 250 is considered high.

The highest PM2.5 reading so far this haze season, 171, was recorded in the west on Oct 9.

When air quality falls into the elevated band, the public is advised to cut back on strenuous outdoor activities for the immediate hour, whereas those in the high band call for avoiding such activities altogether.

Measures to be taken if situation worsens

The government’s haze task force announced a series of measures on Oct 9 should the 24-hour PSI exceed 200 and move into the very unhealthy range.

For one, N95 masks will be distributed to eligible Singaporeans who may be more vulnerable to the effects of haze or who may have limited means of obtaining them.

The masks will be available at PA venues and vending machines at 37 public transport hubs and social services offices.

Those eligible to collect N95 masks include the Pioneer Generation, Merdeka Generation, CHAS orange and blue card holders, and children aged between seven and 16.

All preschools will also be required to cease all outdoor activities and strenuous indoor activities.

Children with chronic heart and lung conditions will be exempted from all indoor physical activities.

In a Facebook post on the evening of Oct 10, Education Minister Desmond Lee said lessons and national examinations will continue in enclosed venues with air purifiers, and schools are ready to step up measures if needed.

Should next-day forecasts enter the hazardous range with a 24-hour PSI exceeding 300, the Ministry of Education (MOE) may consider school closures and the postponement of national examinations, Lee added.

Any such closures will be announced by 8pm the day before through schools and MOE’s official channels.

Meanwhile, sports organisers and facility operators were urged to consider modifying or suspending activities held outdoors and in non-air-conditioned facilities.

Despite the haze, race promoters for the Formula 1 Singapore Airlines Singapore Grand Prix – taking place from Oct 9 to Oct 11 – have said that there are no plans to modify its entertainment activities.