Central Singapore PSI hits 102, air quality enters unhealthy range
Central Singapore's 24-hour Pollutant Standards Index (PSI) reached 102 at 11pm on Sept 9, entering the unhealthy range. The National Environment Agency (NEA) attributes the haze to smoke plumes from fires in Sumatra and Kalimantan, and forecasts the PSI to remain at the higher end of moderate to the lower end of unhealthy.