Haze watch Oct 13: PSI rising across Singapore amid higher PM2.5 readings overnight, remains in unhealthy range
Air quality remains in the unhealthy range across Singapore on Tuesday (Oct 13) morning, with 24-hour Pollutant Standards Index (PSI) readings in the high-unhealthy range in the western and central regions.At 9am, PSI ranged from 127 in northern Singapore to 172 in western Singapore.The next highest reading of 169 was recorded in central Singapore, while readings in the eastern and southern regions were 154 and 134 respectively.Readings of between 101 to 200 are in the unhealthy range, with readings of 167 to 200 considered to be high-unhealthy. Meanwhile, one-hour PM2.5 is in the elevated band across Singapore.In western Singapore, the concentration reading briefly spiked to 171 — in the high band — between 9pm and 10pm.