SINGAPORE - It has been hazy in Singapore on Saturday, and this is likely to continue on Sunday. But there "may be a slight improvement", said the National Environment Agency in an update.

The 24-hour Pollutant Standards Index (PSI) for the next 24 hours is expected to be between the high end of the unhealthy range and the low end of the very unhealthy range. But if the haze conditions improve, the 24-hour PSI may drop to the mid-level of the unhealthy range .

Widespread moderate to dense haze is still persisting in central and southern Sumatra, and some moderate haze has spread to the sea areas south of Singapore. But the haze situation could get better as the prevailing southerly winds are forecast to shift gradually to blow from the southeast.

The haze on Saturday, with worse conditions in the afternoon, was due to haze from the surrounding region being blown in by the prevailing southerly winds. At 6pm on Saturday, the 24-hour PSI was 149 to 188, in the unhealthy range. The three-hour PSI was at 242.

The hazy conditions are expected to continue for the rest of the day.

For updates, visit the NEA website (www.nea.gov.sg), the haze microsite (www.haze.gov.sg), or download the myENV app.