Singapore air stayed unhealthy as haze drove PSI to 155

Air quality across Singapore remained in the unhealthy range on Oct. 12 as transboundary haze from fires in Kalimantan and southern Sumatra continued to drift over the city-state. By evening, the 24-hour Pollutant Standards Index was between 118 and 155, while one-hour PM2.5 readings ranged from 93 to 135. In the west, hourly PM2.5 briefly entered the high band and hit 171 at 9 p.m., matching the highest reading reported this year. The National Environment Agency said moderate to dense smoke plumes were still visible and forecast unhealthy air over the next 24 hours despite some showers. Singapore’s haze task force has said N95 masks will be distributed to vulnerable residents if PSI exceeds 200, and schools may close if forecasts reach the hazardous range above 300.