Singapore

See hourly PM2.5 readings and 24-hr PSI (by National Environment Agency)
See the haze health advisory (by National Environment Agency)
See Haze Situation Updates and Hot Spots map (ASEAN Specialised Meteorological Centre)
See the annual mean exposure to PM2.5 in Singapore (WHO’s BreatheLife campaign)

Background

Like so many other developed nations, Singapore’s air is also affected by air pollution, which comes from industrial and vehicular emissions. Smoke from land and forest fires in the region causes haze that gets blown into Singapore usually between June and September.

Haze

Haze is a local term for air pollution due to forest fires in the Southeast Asian region. It usually occurs during the southwest monsoon season, which lasts from June to September. When neighbouring countries begin burning forests to clear land at the start of the farming season, Singapore is affected by smoke being blown into the country.

Haze Health Advisory FAQs by the Singapore Ministry of Health
The Singapore Ministry of Manpower have specific haze guidelines and advisory for work

Air quality monitoring

The country has been using the Pollutant Standards Index (PSI) to measure pollution levels for major air pollutants. With the release of the WHO Air Quality Guidelines, the National Environment Agency (NEA) formed the Advisory Committee on Ambient Air Quality (2010). The Committee recommended alignment with the WHO AQGs recognising the WHO-led guidelines to be backed with studies and scientific data.

The NEA has set air quality targets by 2020, setting values lower than the WHO Interim Target.

As of 01 April 2014, Singapore adopted an integrated air quality index. The pollutants being measured using the Pollutant Standards Index (PSI) are sulphur dioxide (SO₂), particulate matter (PM₁₀), fine particulate matter (PM_2.5), nitrogen dioxide (NO₂), carbon monoxide (CO) and ozone (O₃).

Air quality and hourly PM2.5 levels

The hourly PM2.5 levels are published. During the haze season, these levels indicate the air quality status. Authorities advise that the hourly PM2.5 levels should be used as a guide by the public to decide on what outdoor activities they can undertake immediately. The 24-hour PSI can be used to plan outdoor activities for the next day.

Band 1 (NORMAL) (0-55μg/m³)	Band 2 (ELEVATED) (56-150 μg/m³)	Band 3 (HIGH) (151-250 μg/m³)	Band 4 (VERY HIGH) (>=251 μg/m³)
Continue with normal activities	Reduce strenous outdoor activity for the next hour	Avoid strenous outdoor activity for the next hour	Minimise all outdoor activity for the next hour
Continue with normal activities	Vulnerable people should avoid strenous outdoor activity for the next hour	Vulnerable people should avoid all outdoor activity for the next hour	Vulnerable people should avoid all outdoor activity for the next hour

Air quality and PSI

PSI VALUE	AIR QUALITY DESCRIPTOR
0-50	Good
51-100	Moderate
101-200	Unhealthy
201-300	Very Unhealthy
Above 300	Hazardous

Health advisories

To limit the adverse effects of haze, advice on the level of outdoor activities and physical exertion is given to the general population, to elderly and children and those with chronic medical conditions.

24-hr PSI	Healthy Person	Elderly, pregnant women, children	Persons with chronic lung disease, heart disease
0-100 (Good/Moderate)	Normal activities	Normal activities	Normal activities
101-200 (Unhealthy)	Reduce prolonged or strenuous outdoor physical exertion	Minimise prolonged or strenuous outdoor physical exertion	Avoid prolonged or strenuous outdoor physical exertion
201-300 (Very unhealthy)	Avoid prolonged or strenuous outdoor activity	Minimise outdoor activity	Avoid outdoor activity
>300 (Hazardous)	Minimise outdoor activity	Avoid outdoor activity	Avoid outdoor activity

Reviewed: September 2026

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