Singapore, Singapore Air Quality & Smog

Dominant pollutants, when pollution and smog are worst, a notable historical episode, and the official monitoring agencies for Singapore, Singapore — plus how to check the current reading. Singapore reports air quality on the Pollutant Standards Index (PSI) — our full guide explains how that scale works and how it compares to the US AQI.

Dominant pollutants

PM2.5 (haze), PM10, ozone.

Seasonal pattern: when smog is worst

For most of the year Singapore's air is good, ventilated by maritime winds. The major exception is the transboundary haze season, roughly June to October, when smoke from land and peat fires in the wider region drifts over the island. Haze years are worst during dry El Niño phases. Because the headline PSI is a 24-hour figure that lags a fast-moving plume, the NEA also publishes a 1-hour PM2.5 reading — the number to watch when haze is active.

A notable air-quality episode

During the June 2013 haze, Singapore's 3-hour PSI hit a record of around 400 (Hazardous) on 21 June, the worst in the nation's history at the time. The 2015 episode was less intense but far more prolonged, lingering for weeks.

The local index and who runs it

Singapore reports air quality using the Pollutant Standards Index (PSI), not the US AQI — so the same air can read as a different number than you may be used to. The NEA haze portal and the myENV app publish both the 24-hour PSI by region and the 1-hour PM2.5 reading. During haze, NEA's activity advisories are keyed to the 1-hour PM2.5 band.

• National Environment Agency (NEA)

How to check air quality in Singapore

For the official live reading, the agency portals above are the canonical source. To understand what the numbers mean, start with our guide to the Pollutant Standards Index (PSI) and the broader comparison of world air-quality indices. Smog Report puts glanceable air quality on your iPhone — widgets, Live Activities, Siri, and Apple Watch — free and with no account.

Common questions about Singapore air quality

Why does Singapore have air-quality and smog problems?

For most of the year Singapore's air is good, ventilated by maritime winds. The major exception is the transboundary haze season, roughly June to October, when smoke from land and peat fires in the wider region drifts over the island. Haze years are worst during dry El Niño phases. Because the headline PSI is a 24-hour figure that lags a fast-moving plume, the NEA also publishes a 1-hour PM2.5 reading — the number to watch when haze is active.

What are the main air pollutants in Singapore?

Singapore's dominant pollutants are PM2.5 (haze), PM10, ozone. The reading on any given day is usually driven by whichever of these is highest.

Has Singapore had a major air-quality or smog event?

During the June 2013 haze, Singapore's 3-hour PSI hit a record of around 400 (Hazardous) on 21 June, the worst in the nation's history at the time. The 2015 episode was less intense but far more prolonged, lingering for weeks.

What air-quality index does Singapore use?

Singapore reports air quality on the Pollutant Standards Index (PSI) (PSI), not the US AQI — so the same air can read as a different number than you may be used to. For live, glanceable readings on your iPhone, the free Smog Report app auto-selects the right local index for wherever you are.

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