Singapore Air quality today

What is the haze, and where does it come from?

The haze is smoke from regional forest fires, which start when open burning is used to clear land for farming ^[1]. NEA, Singapore's National Environment Agency, says the haze that reaches Singapore mainly comes from forest and peat fires in the region ^[3]. Besides smoke particles, these fires give off a mix of gases that cause an acrid burning smell ^[3].

Haze is often worse in dry periods, when rain is low, and when the wind changes direction ^[1]. In June 2013, NASA satellites saw smoke from illegal fires on Sumatra blowing east toward southern Malaysia and Singapore ^[4]. NASA noted that farmers in Sumatra often burn forests in the dry season to prepare soil for new crops, though local laws ban it ^[4].

When is haze season in Singapore?

Singapore has two monsoon seasons. The Northeast Monsoon runs from December to early March, and the Southwest Monsoon from June to September ^[2]. In the Southwest Monsoon, winds generally blow from the southeast or south ^[2].

The Meteorological Service Singapore says slight to moderate haze is common during the Southwest Monsoon ^[2]. NEA says prevailing winds sometimes carry smoke from the forest fires over Singapore, particularly during the Southwest Monsoon ^[1].

In July 2026, with El Nino conditions building, a climate and health research centre at Nanyang Technological University said haze episodes were more likely between July and October that year ^[8]. It named August and September as the greatest concern, and linked the risk to southwest monsoon winds that can carry smoke toward Singapore ^[8].

What are the PSI and PM2.5, and is the PSI the same as the AQI?

PM2.5 is fine particulate matter, meaning very small particles in the air ^[3]. It is the main pollutant when transboundary haze, haze blown in from other countries, reaches Singapore ^[3]. The PSI, or Pollutant Standards Index, is Singapore's main measure of air pollution ^[4]. NEA works it out from 24-hour averages of six pollutants, and the highest of their sub-scores becomes the PSI ^[3]. PM2.5 was added as the sixth pollutant in April 2014 ^[3].

NEA's PSI bands are 0 to 50 Good, 51 to 100 Moderate, 101 to 200 Unhealthy, 201 to 300 Very Unhealthy, and above 300 Hazardous ^[3]. NEA also publishes 1-hour PM2.5 readings, a key sign of the air at that moment ^[3]. Outside haze periods, NEA's records show 1-hour PM2.5 stays below 55 micrograms per cubic metre about 99 per cent of the time ^[3].

NASA describes the PSI as similar to the Air Quality Index, or AQI, used by the US Environmental Protection Agency ^[4]. NEA says Singapore referred to the US system, but the two are not identical, and indices from other websites are not comparable with the 24-hour PSI ^[3].

What were Singapore's worst haze episodes?

In June 2013, the PSI rose to 371 on June 20, which NASA reported as the highest level ever recorded at the time ^[4]. The earlier record was 226, set in 1997 ^[4].

NEA's records show haze episodes in September 2015 and September 2019, when transboundary haze affected Singapore ^[3]. Between 9 and 23 September 2019, smoke from land and vegetation fires in Sumatra brought hazy conditions ^[5]. The 24-hour PSI peaked at 154, in the Unhealthy range, in southern Singapore on 19 September 2019 ^[5]. Showers in the last week of that month helped ease the haze ^[5].

What is Singapore doing about the haze?

In August 2014, Singapore's Parliament passed the Transboundary Haze Pollution Act 2014 ^[7]. It lets regulators prosecute companies and individuals that cause severe air pollution in Singapore by burning forests and peatlands in neighbouring countries ^[7]. The law was first proposed after fires in Indonesia spiked in June 2013 ^[7].

NEA leads a Haze Task Force of 28 government agencies, which makes and carries out plans to manage the impact of haze ^[3]. NEA and the Meteorological Service Singapore also host the ASEAN Specialised Meteorological Centre, which monitors forest fires and smoke haze in the ASEAN region of Southeast Asia ^[1].

How to protect yourself in Singapore

NEA says reducing outdoor activity and physical effort can help limit the ill effects of haze ^[1]. Use the 24-hour PSI forecast to plan ahead, and the 1-hour PM2.5 reading for things you are about to do, like going for a jog ^[6].

When the PSI is in the Unhealthy range, the official health advisory says healthy people should reduce prolonged or strenuous outdoor exertion ^[3]. Older people, pregnant women and children should minimise it, and people with chronic lung or heart disease should avoid it ^[3]. At Hazardous levels, healthy people should minimise outdoor activity, and the other groups should avoid it ^[3].

Anyone who does not feel well, especially older people, children and people with chronic heart or lung conditions, should seek medical attention ^{[1] [6]}.