At 3pm, the 24-hour PSI readings ranged from 96 to 119.
SINGAPORE: Air quality improved across Singapore on Sunday (Oct 25), with the 24-hour Pollutant Standards Index (PSI) readings in two regions dropping into the good to moderate band.
The reading in the south dropped out of the unhealthy range at 10am when it dipped to 100, and that in the north followed at 1pm as it fell to 99. At 3pm, the readings in the south and north stood at 96 and 97, respectively.
Readings in western, central and eastern Singapore were also declining but remained in the unhealthy band, ranging from 103 to 121.
Hourly PM2.5 readings, meanwhile, were in the normal band in all five regions, ranging from 20 to 30.
In its evening advisory on Saturday, the National Environment Agency (NEA) said the 24-hour PSI for Sunday was expected to range from 80 to 130, spanning the good to moderate and unhealthy bands.
"Winds are expected to blow from the southwest or west, which could limit transport of smoke haze to Singapore," the agency said, adding that expected showers over Singapore and the surrounding region could help with haze conditions.
The winds are expected to continue blowing from the southwest or west on Monday and Tuesday.
"With showers expected over Singapore and the vicinity, the haze situation is likely to improve," said NEA.
NEA has advised the public to refer to the 24-hour PSI forecast when planning outdoor activities and to check the latest 1-hour PM2.5 readings before undertaking immediate outdoor activities.
When hourly PM2.5 concentrations are in the elevated band, healthy individuals should reduce strenuous outdoor activities for the next hour.
Vulnerable groups, including children, elderly people, pregnant women and those with chronic heart or lung conditions, should avoid strenuous outdoor activities during that period.
For Sunday, NEA advised healthy individuals to reduce prolonged or strenuous outdoor physical exertion, while elderly people, pregnant women and children should minimise such activities.
People with chronic heart or lung disease should avoid prolonged or strenuous outdoor physical exertion.