SINGAPORE - The slightly hazy conditions in Singapore on Wednesday afternoon were due to smoke haze from fires in Sumatra, blown in by prevailing south-southwesterly winds, the National Environment Agency said.
The 24 hour PSI (Pollutant Standards Index) was between 62 and 68 - the moderate range - as of 7pm on Wednesday.
The NEA added in its statement that the figure may rise overnight but activities can go on as usual.
The 24 hour PSI is expected to be in the high end of the moderate range on Thursday, and may climb to the low end of the unhealthy range if prevailing winds continue to blow from the south or southwest.
The NEA said it had observed smoke plumes from hotspots in central and southern Sumatra in the past few days. It detected 116 hotspots on Monday, 42 on Tuesday, and 12 on Wednesday.