SINGAPORE, Oct. 4 -- Air quality in the Republic improved this morning as 24-hour Pollutant Standards Index (PSI) in central Singapore returned to the moderate range.

It entered the unhealthy range at 11am yesterday.

At 10am today, PSI readings across Singapore ranged from 76 to 99 - in the moderate range. The highest reading of 99 was recorded in the central region.

Meanwhile one-hour PM2.5, an indicator of fine particulate matter in the air, ranged between 15 and 44. Concentration readings from 0 to 55 denote the normal band.

In its daily haze situation update yesterday evening, the National Environment Agency (NEA) said the country's 24-hour PSI is forecast to be in the high-moderate to low-unhealthy range.

It noted that moderate ...