Singapore Air Quality Reaches Unhealthy Range Amid Sumatra Smoke Haze
- Air quality across Singapore reached the unhealthy range as transboundary smoke haze drifted from Sumatra and Kalimantan, prompting government advisories and workplace safety protocols.
- Air quality deteriorated gradually on October 23, 2026, when the western and central regions of Singapore were the first to enter the unhealthy range.
- The NEA forecasted the 24-hour Pollutant Standards Index for October 24, 2026, to range between 90 and 140, falling into the moderate to unhealthy bands.
Air quality across Singapore reached the unhealthy range as transboundary smoke haze drifted from Sumatra and Kalimantan, prompting government advisories and workplace safety protocols.
Smoke Haze Blankets Western and Central Regions
Air quality deteriorated gradually on October 23, 2026, when the western and central regions of Singapore were the first to enter the unhealthy range. Dry weather conditions persisted across the island, fueling the buildup of pollutants as smoke haze from Sumatra and Kalimantan was observed drifting toward the country, according to the National Environment Agency (NEA).
The NEA forecasted the 24-hour Pollutant Standards Index for October 24, 2026, to range between 90 and 140, falling into the moderate to unhealthy bands. During this period, 1-hour PM2.5 concentration readings reached between 70 and 98 micrograms per cubic meter, placing them in the elevated band.
Ministry Issues Strict Workplace Guidelines for PM2.5 Spikes
In response to changing air quality, the Ministry of Manpower (MOM) issued additional guidance instructing employers to adjust outdoor work based on hourly PM2.5 readings rather than relying solely on the 24-hour PSI forecast. Minister of State for Manpower Dinesh Vasu Dash emphasized that worker health and safety must remain a priority during the haze period.
Under the ministry guidelines, employers must prohibit outdoor work for vulnerable employees—such as the elderly, pregnant women, and those with chronic heart or lung diseases—when hourly PM2.5 levels reach the very high band of 251 and above. When concentrations hit the high band of 151 to 250, healthy employees must avoid strenuous outdoor work, while vulnerable staff must avoid outdoor work entirely unless masks or appropriate respirators are provided.
Earlier Spikes and Regional Improvements
The current smoke haze follows a series of fluctuating air quality conditions that began earlier in the month. On October 9, 2026, northern regions first recorded improvements, and by noon on October 19, 2026, hourly PM2.5 readings had temporarily returned to normal bands across all five regions, marking a brief respite from a smog-filled period, Secret Singapore reported.
However, conditions worsened again over the weekend as the west region hit a 24-hour PSI of 230 on Sunday morning, representing the highest recorded figure of the 2026 haze season. By Monday, the west region’s reading dropped to 115, while the north improved to a moderate level of 85, according to The Independent Singapore.
Showers Forecasted to Ease Regional Air Pollution
Showers are forecast over Singapore and the surrounding region, although smoke haze may continue to transport from Sumatra under prevailing south-southeasterly or south-southwesterly winds. Conditions could improve from Sunday onward, when winds are expected to shift toward the southwest or west, potentially reducing the influx of transboundary smoke.
Despite the anticipated wind shift and cleansing showers, the broader regional haze situation remains a concern. Scattered hotspots were detected in southern Sumatra and Kalimantan in the regional weather and haze assessment, indicating that transboundary smoke will likely persist as long as dry conditions and agricultural fires continue in neighboring Indonesia.