Haze in Singapore: Air quality at unhealthy range in two regions

Singapore began Saturday with unhealthy air quality in two regions, as the 24-hour Pollutant Standards Index reached 119 in the central area and 102 in the west at 7 a.m., according to the National Environment Agency.

The east, north and south remained in the moderate range, with readings of 99, 85 and 88 respectively. The index entered the unhealthy band of 101 to 200 on Friday, the first time it had crossed that threshold since Oct. 8, 2023.

The change prompted the agency to issue daily haze advisories, including a 24-hour forecast. It said Singapore could continue to face transboundary haze, with conditions expected to range from the higher end of moderate levels to the middle of the unhealthy range.

Singapore’s 24-hour PSI combines readings for six pollutants, including fine particulate matter, ozone and sulphur dioxide. The agency separately tracks one-hour PM2.5 levels, which show air quality at a single point in time. A PSI reading from 201 to 300 is considered very unhealthy, while a reading above 300 is hazardous.