Haze watch: Air quality in Singapore deteriorates overnight, unhealthy PSI in 3 regions
Residents in Singapore woke up to unhealthy air quality again with three regions in the unhealthy range on Sunday (Sept 27) morning.The 24-hour Pollutant Standards Index (PSI) turned unhealthy in central Singapore at 8pm on Saturday, with the western and eastern regions also entering the range at 12am and 1am respectively.Meanwhile, one-hour PM2.5 reached as high as 131 in central Singapore at 9pm on Saturday before gradually easing back to the lower-end of the elevated band.At 9am, PSI ranged from 90 to 130 — in the moderate to unhealthy range — with central Singapore recording the highest reading of 130.One-hour PM2.5 is the normal band for the northern, western and southern regions, while central (68) and eastern (58) Singapore have an elevated concentration reading.