SINGAPORE, Sept. 30 -- Air quality in northern Singapore improved overnight, falling back into the moderate range at 3am on Wednesday (September 30).

Elsewhere, the 24-hour Pollutant Standards Index (PSI) remains in the unhealthy range.

At 8am, PSI ranged between 112 to 118 in eastern (118), southern (112), western (118) and central (117) Singapore.

Meanwhile, one-hour PM2.5 is in the elevated band in all five regions, with eastern Singapore recording the highest concentration reading of 79.

Members of the public should note that the health impact of haze is dependent on one's health status, the PSI level, as well as the length and intensity of outdoor activity.

Those intending to participate in immediate outdoor activities should ch...