Singapore air quality improves to moderate levels after unhealthy readings

Singapore’s air quality returned to the moderate range on Saturday after three regions recorded unhealthy readings earlier in the day. The central region’s 24-hour Pollutant Standards Index fell to 93 by 11pm, from a peak of 123 at 1am.

The western and eastern regions also improved, recording PSI readings of 88 and 78 at 11pm. Both had entered the unhealthy range earlier, with readings of 103 in the west and 102 in the east at 6am. The northern and southern regions stayed moderate throughout the day, ending at 75 and 74 respectively.

The 24-hour PSI entered the unhealthy band of 101 to 200 at 7am on Friday. It marked the first time the index had exceeded 100 since October 8, 2023, prompting the National Environment Agency to begin issuing daily haze advisories and forecasts to help people plan activities and events.

The agency said Singapore could continue to experience transboundary haze if fires in Indonesia remain active. Smoke plumes over southern and central Sumatra and parts of Kalimantan continued drifting toward Singapore, while dry conditions and southeasterly or southerly winds were expected to persist in the coming days.

The 24-hour PSI measures six pollutants and forms the basis of Singapore’s daily health advisories. The agency said a reading from 201 to 300 is considered very unhealthy, while a reading above 300 is hazardous.