Air quality unhealthy across Singapore amid haze, PM2.5 readings elevated in most regions

Singapore continued to experience hazy conditions overnight, with the 24-hour Pollutant Standards Index (PSI) remaining within the unhealthy range across all regions, according to the National Environment Agency (NEA). The highest 24-hour PSI reading of 173 was recorded in the west at 6am, followed by 166 in the central region, 148 in the east, 131 in the south, and 126 in the north. Air quality is deemed unhealthy when the PSI falls between 101 and 200.

Hourly PM2.5 readings, used as a gauge for current air quality, were elevated in four regions: central (110), east (99), west (97), and south (76). Only the north region had a reading of 55, which is considered normal. PM2.5 scores from 0 to 55 represent normal values, between 56 and 150 indicate an elevated concentration of fine particles, and scores between 151 and 250 are considered high.

The NEA forecast that the 24-hour PSI for Singapore would remain in the unhealthy range in its daily haze advisory on October 12. Smoke plumes from fires in Kalimantan and southern Sumatra continued to drift towards Singapore under prevailing south-easterly winds. While some showers are expected over Singapore and surrounding regions, dry conditions are forecast to persist over parts of southern Sumatra and Kalimantan, NEA noted.

This was the first time since October 2023 that air quality in Singapore breached the unhealthy level, which occurred on September 4. The NEA began issuing daily haze advisories from the evening of that day. The haze task force announced that it would distribute N95 masks to eligible Singaporeans when air quality reaches "very unhealthy" levels, denoted by a PSI reading between 201 and 300.