24-hour PSI in good to moderate range across Singapore for first time since Oct 5
However, the National Environment Agency said it expected the 24-hour PSI to be in the unhealthy band on Friday.
Haze shrouding buildings in the CBD from Elgin Bridge at 1.10pm on Oct 21, 2026. (Photo: CNA/Ooi Boon Keong)
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SINGAPORE: Air quality in Singapore improved on Thursday (Oct 22), with the 24-hour Pollutant Standards Index (PSI) readings in the country's five regions all standing in the good to moderate band for the first time since Oct 5.
The central region's reading dropped out of the unhealthy range at 4am, and the west's followed at 3pm. Readings in the other three regions have been in the moderate range throughout the day.
At 9pm, the 24-hour PSI readings ranged from 71 to 88.
Hourly PM2.5 readings were in the normal range in all regions, from 1am to 8pm. However, the western region entered the elevated band at 9pm with a reading of 70, before returning to a normal reading of 51 at 11pm. The other region's readings ranged from 26 to 41.
The National Environment Agency (NEA) said in its evening advisory that most of the smoke haze from Kalimantan and Sumatra remained to the south of Singapore due to the northeasterly and easterly winds.
"There was some smoke haze at higher altitudes above Singapore but limited mixing to surface levels," it said.
On Monday, Singapore saw a brief improvement in air quality when PSI readings fell into the moderate range in three of the country's five regions for the first time in more than a week.
Before Monday, the last time Singapore recorded moderate air quality in any region was on Oct 9.
The last time all five regions recorded moderate air quality simultaneously was at midnight on Oct 5, when 24-hour PSI readings ranged from 77 to 100.
UNHEALTHY AIR QUALITY FORECAST FOR FRIDAY
NEA said it expected the 24-hour PSI to be in the unhealthy band on Friday, ranging from 101 to 150.
"As dry conditions are expected to persist over the southern parts of Sumatra and Kalimantan, smoke haze may be transported towards Singapore under prevailing southeasterly winds," it said.
Smoke haze might also drift over from Sumatra on Saturday due to expected southeasterly or southerly winds, said the agency.
"However, showers over Singapore and the vicinity could help with the situation," it said, adding that hazy conditions were expected to improve on Sunday due to showers and favourable winds.
ADVICE FOR VULNERABLE GROUPS
When the 24-hour PSI is in the unhealthy range, NEA advises the elderly, pregnant women and children to minimise prolonged or strenuous outdoor physical exertion.
People with chronic diseases, including heart or lung conditions, should avoid such activities.
For decisions on mask use and immediate outdoor activities, the public should refer to the one-hour PM2.5 readings instead.
When the 1-hour PM2.5 readings are in the high band, vulnerable individuals, including the elderly, pregnant women and those with chronic heart or lung conditions, should avoid outdoor activities, according to the Ministry of Health (MOH).
Those who need to go outdoors for immediate activities may wear a well-fitting N95 mask or equivalent to reduce their exposure to haze particles.
When 1-hour PM2.5 readings reach the very high band of 251 and above, healthy individuals should also minimise all outdoor activities. Those who need to venture outdoors may similarly use an N95 mask for protection.
However, MOH said N95 masks are generally not needed for commuting between home and school or work, or in indoor environments.
The ministry has also advised the elderly, pregnant women and those with severe heart or lung conditions who experience breathing difficulties to consult their doctor before using an N95 mask.
Those who experience discomfort while wearing one should take a break from using it.
Besides N95 masks, KN95, FFP2 and KF94 masks are also effective in reducing exposure to haze particles, according to MOH.
Members of the public can visit the HazeMaskGoWhere website for more information on collection locations and live updates on mask availability at the vending machines.
MOH had also issued guidance on Oct 13 on the types of masks that can be used for protection against haze.
It said surgical masks can help reduce discomfort and the risk of infections by providing a barrier against larger irritant particles.
However, if PM2.5 readings are above 250 and people need to be outdoors for several hours, MOH recommends wearing an N95 or equivalent mask.
Cloth masks generally do not filter fine particles effectively, although they can reduce discomfort by blocking larger irritant particles in the air.
