Haze returns to unhealthy levels in Singapore as smoke drifts from Indonesia

SINGAPORE, Sept 19 — The haze situation has deteriorated in parts of South-East Asia, with Singapore's air quality slipping back into the "unhealthy" range due to smoke from Indonesian forest fires. According to the National Environment Agency (NEA), the 24-hour Pollutant Standards Index (PSI) in the city-state's central region reached 107 by 3pm, up from 102 at 1pm.

The west region's reading was the next-highest at 95, while the south recorded 79, all remaining within the moderate range. The central region experienced the most significant increase, with the hourly PM2.5 reading surging from 67 at 11am to 117 at noon, before dropping to 93 by 3pm. The NEA advises the public to monitor hourly PM2.5 readings for immediate outdoor decisions and the 24-hour PSI for daily planning.

This recent decline follows an earlier bout of unhealthy air in Singapore on September 4, with the central-region PSI hitting 101. The NEA attributes the latest haze to smoke plumes from Kalimantan and some from southern Sumatra drifting towards Singapore. Dry conditions are expected to persist in southern Sumatra and Kalimantan, while prevailing winds could bring additional smoke.

The NEA had predicted the 24-hour PSI to stay in the high-moderate to low-unhealthy range. The return of unhealthy air marks the first such instance in Singapore since October 2023, following previous warnings of increased haze risks between June and October due to El Nino and the Indian Ocean Dipole conditions.