If you’ve stepped outside recently and noticed a distinctly smoky smell or a washed-out sky, you’re not imagining things—Singapore’s air quality has taken a turn for the worse.
On the morning of September 15, the 24-hour Pollutant Standards Index (PSI) crossed into the unhealthy range across the island, with readings ranging from 104 in the north to 154 in central Singapore. The National Environment Agency (NEA) attributes the deteriorating conditions to regional fires burning across Sumatra and Kalimantan, and officials warn that the situation could persist as dry weather continues.
Here’s a breakdown of what’s happening, where the smoke is coming from, and how to protect yourself.
Where Is the Smell Coming From?
According to the NEA, satellite monitoring has detected clusters of hotspots across central and southern Sumatra, as well as parts of Kalimantan on the Indonesian side of Borneo. Moderate to dense smoke haze has also been observed over portions of Borneo, Sumatra, and southern Peninsular Malaysia.
Smoke plumes are visibly drifting from these hotspots, and with dry conditions expected to persist across the region, the haze is likely to remain elevated for some time. Whether more smoke reaches Singapore depends on wind patterns, with prevailing winds currently forecast to blow from the southeast or south—potentially funneling additional haze toward the island.
What Do the PSI Readings Mean?
At 6 a.m. on September 15, the 24-hour PSI readings stood at:
- North: 104
- South: 111
- East: 128
- West: 128
- Central: 154
A PSI reading between 101 and 200 is classified as unhealthy, according to NEA guidelines. At this level, the agency advises reducing outdoor activities, particularly for sensitive groups.
Beyond the visible haze, the fires are generating fine particulate matter, including PM2.5—microscopic particles that can penetrate deep into the lungs when inhaled. These particles pose the greatest health risk, as they can trigger respiratory irritation and exacerbate existing conditions.
Why Do Haze Levels Vary Across the Island?
Air quality isn’t uniform across Singapore. Depending on wind direction and the movement of smoke plumes, some neighbourhoods may experience significantly worse conditions than others. On this particular morning, central Singapore recorded the highest PSI, well into the unhealthy range.
Don’t assume that a clearer sky in your area means the whole island is unaffected. Regional weather patterns can shift quickly, meaning conditions may change from hour to hour.
Can I Still Go Out?
If you’re planning outdoor activities, the NEA recommends scaling back when PSI levels enter the unhealthy range. This is especially important for vulnerable individuals—including children, older adults, pregnant women, and those with heart or lung conditions.
For generally healthy people, going out when necessary is still possible, but it’s wise to minimise strenuous exercise. If you experience eye irritation, coughing, or breathing discomfort, head indoors and limit further exposure.
A practical tip: Keep an eye on two readings. Use the 24-hour PSI and its corresponding health advisory to plan your day’s activities, and check the one-hour PM2.5 concentration when making immediate decisions about heading outside.
Where to Stay Updated
For real-time air quality updates, visit the NEA’s haze website at haze.gov.sg or download the myENV app for push notifications and location-based advisories.
As the region heads into its traditional dry season, the haze situation may continue to fluctuate. Staying informed and adjusting your plans accordingly remains the most effective way to protect your health during this period.