Winds bring haze back to Singapore: Hourly PM2.5 in elevated band islandwide
Singapore's "oxygen pass" expired on Friday (October 23) afternoon, as prevailing winds brought smoke haze back from fires in Indonesia's Kalimantan and Sumatra.At 1pm, hourly PM2.5 was in the elevated band (56 to 150µg/m3) in all five regions.Concentration readings ranged from 56 in northern Singapore to 84 in southern Singapore.Meanwhile, the 24-hour Pollutant Standards Index (PSI) remains in the good-to-moderate range (0 to 100).It is expected to climb into the unhealthy range if PM2.5 readings remain elevated over the next few hours.Checks on the Meteorological Service Singapore's weather site show that winds are predominantly from the south, making the haze situation not unexpected.In its daily haze situation update on Thursday evening, the National Environment Agency (NEA) had said that the country's 24-hour PSI forecast is between 101 and 150 — in the unhealthy range.