Air quality improves as 24-hour PSI returns to moderate in all 5 Singapore regions

Residents in Singapore can now breathe better as air quality has improved, with 24-hour Pollutant Standard Index (PSI) for all regions in the Republic returning to the moderate range on Wednesday (Sept 16).Data from the National Environment Agency (NEA) shows that 24-hour PSI at 11am was between 74 and 99 — in the moderate range — with the highest reading of 99 recorded in central Singapore.Meanwhile, one-hour PM2.5 concentration readings ranged between 20 and 26, in the normal band. This includes central Singapore, which has recorded higher PSI and one-hour PM2.5 readings over this week.In its daily haze situation update on Sept 15, NEA said the country’s 24-hour PSI forecast is again expected to be in the high moderate to mid-unhealthy range over the next 24 hours.Explaining this in its daily haze situation update on Tuesday evening, NEA said that while overnight showers over some areas in the surrounding region contributed to improvements in the haze situation, prevailing winds — from the east-southeast and southeast directions — had brought smoke haze from Kalimantan and Sumatra to Singapore.