Smoke from southern Sumatra pushed Singapore's air quality into unhealthy territory overnight and into Monday morning. The National Environment Agency detected clusters of scattered hotspots in southern Sumatra and Kalimantan, with moderate to dense smoke plumes drifting northwards toward Singapore and Peninsular Malaysia.
The deterioration matters for outdoor plans. Healthy people are advised to reduce strenuous outdoor activity when 1-hour PM2.5 levels are raised. Elderly people, pregnant women, children, and people with chronic heart or lung conditions should avoid strenuous outdoor activity altogether during elevated readings.
At 1pm on Monday, the 24-hour PSI reading stood at 118 in the central region and 110 in the west, both in the unhealthy range of 101 to 200. The 1-hour PM2.5 reading was elevated in both regions; it stood at 93 in the central region and 81 in the west. Air quality for the rest of the island remained in the moderate range. Earlier that morning at 6am, the central region's PSI had been at 110 and the west at 102.
The National Environment Agency forecast dry conditions to continue over Singapore and the surrounding region, coupled with prevailing south-easterly or south-westerly winds. This combination means a continued risk of smoke haze affecting Singapore. The agency recommends referring to the 1-hour PM2.5 readings and corresponding personal guide for immediate outdoor activities, and using the 24-hour PSI forecast and health advisories when planning activities for the next day.