PSI Hits 104 in Eastern Singapore as Regional Haze Pushes Air Quality Into Unhealthy Range
The air quality in eastern Singapore officially crossed into the unhealthy threshold on the evening of Sept 4, registering a 24-hour Pollutant Standards Index (PSI) reading of 102 at 9pm before climbing to 104 by 11pm, according to data from the National Environment Agency (NEA). Driven by persistent forest and land fires in Sumatra and Kalimantan, Indonesia, the return of regional haze marks the last time Singapore’s air quality hit unhealthy levels since October 2023.
How the Haze Spread Across the Island
The escalation began early in the day. The central region recorded a PSI reading of 101 at 7am on Sept 4, before worsening significantly to 123 by 11pm. By late evening, the eastern sector joined the central region in the unhealthy band—defined as a PSI reading between 101 and 200—prompting official advisories for residents to cut down on outdoor activities.
Meanwhile, air quality in other parts of the island hovered just below the threshold. At 11pm, the NEA reported PSI readings of 88 for the north, 87 for the south, and 99 for the west. However, meteorological forecasts indicate that conditions may remain volatile. According to NEA updates, haze could persist into Sept 5, with overall air quality anticipated to fluctuate between the higher end of the moderate range and the middle of the unhealthy range.
Regional Weather Patterns and the El Niño Factor
The sudden drop in air clarity is tied directly to environmental conditions across maritime Southeast Asia. In a weather advisory issued on Sept 1, the Meteorological Service Singapore warned that dry weather would dominate the region through the first fortnight of September, despite sporadic showers expected in the second week.
This prolonged dryness has fueled an increase in hotspots and smoke haze across Sumatra and Kalimantan, phenomena intensified by a super El Niño weather pattern. Dense smoke haze has blanketed parts of southern and central Sumatra as well as various parts of Kalimantan on most days from around Aug 21. How severely Singapore’s skyline is obscured depends heavily on shifting wind directions.
Contingency Plans and Public Health Preparations
With air quality teetering on the edge of unhealthy levels, authorities are preparing for worse scenarios. Around noon on Sept 4, the Haze Task Force outlined a series of contingency measures set to activate if the PSI breaches 200 and enters the “very unhealthy” category.
Among these preparations is a directive to open air-conditioned rooms across all community centres and selected residents’ committee centres, offering public sanctuaries for people seeking respite from the bad air.
As the smoke lingers over the horizon, we want to hear from you. How are you and your family adapting to the return of the haze in your neighborhood? Share your experiences in the comments below.
