Central Singapore's Air Crosses into 'Unhealthy' on Saturday Morning as 24-Hour PSI Hits 105
SINGAPORE — Air quality in central Singapore crossed into the unhealthy range at 11 a.m. on Saturday, October 3, while readings in the other four regions remained moderate. By 1 p.m., the central region's 24-hour Pollutant Standards Index (PSI) had risen to 105, with the east at 96, the west at 93, the south at 87 and the north at 77. The 1-hour PM2.5 reading in the central region was in the elevated band at the same time.
The latest readings followed the National Environment Agency's (NEA) advisory on Friday evening that moderate to dense smoke plumes from southern Sumatra were drifting towards Singapore under southeasterly or southerly winds, with smoke haze also observed from fires in Kalimantan. Dry conditions persisted over Singapore and the surrounding region on Saturday, and the NEA had forecast the 24-hour PSI in the moderate to low-unhealthy range — Saturday's central reading landed at the top of that range.
The 24-hour PSI is Singapore's headline daily air-quality indicator and the basis of the NEA's daily health advisories. It is calculated from six pollutants — PM2.5, PM10, ozone, sulphur dioxide, nitrogen dioxide and carbon monoxide — and reflects the average air quality of the past 24 hours. The 1-hour PM2.5 reading reflects conditions at a point in time; PM2.5, fine particulate matter 2.5 micrometres or smaller, is the dominant pollutant during haze. A 24-hour PSI of 101–200 is 'unhealthy', 201–300 'very unhealthy', and above 300 'hazardous'.
The NEA's advisories by PSI band say that when air is in the unhealthy range, healthy people should reduce prolonged or strenuous outdoor exertion, while the elderly, children, pregnant women and those with chronic lung or heart diseases should minimise or avoid it. How soon the haze eases depends on the fires in Indonesia and on the wind; the agency updates its monitoring and forecasts daily.
Sources: Compiled from Business Today's October 3, 2026 report citing NEA data, and Meteorological Service Singapore haze updates.
Published by GSM · USA (original Chinese edition)
Photo: 新加坡武吉知马一带烟霾中的太阳，Sgconlaw 摄，CC BY-SA 4.0（Wikimedia Commons）
