Singapore air pollution soars as Indonesian wildfire haze blankets Southeast Asia

Singapore has been engulfed by thick haze from wildfires in Indonesia, pushing air pollution to among the highest levels in the world and raising concerns about public health and outdoor activities ahead of the city's Formula One weekend.

Air quality in Singapore entered the unhealthy range, with the National Environment Agency (NEA) reporting a 24-hour Pollutant Standards Index (PSI) of 105 to 140 on Wednesday evening. The agency said smoke plumes from southern Sumatra and Kalimantan were drifting towards the city-state.

Data from IQAir had placed Singapore as the world's most polluted major city on Wednesday, with air quality reaching the “very unhealthy” category. Kuala Lumpur, which had earlier occupied the top position, was ranked second.

Indonesian fires drive regional haze

The haze is linked to widespread wildfires across Indonesia, where unusually dry conditions have intensified the annual fire season.

The situation has been exacerbated by a particularly strong El Niño, with rainfall across the region reportedly around 80% below normal since June. Indonesia is experiencing its most intense wildfire season in more than a decade, while peatland fires remain a particular concern because they can smoulder underground and reignite even after surface fires appear to have subsided.

The haze has spread beyond Indonesia, affecting Singapore, Malaysia, Brunei and parts of the Philippines. Singapore's NEA said moderate to dense smoke haze had been observed across parts of Peninsular Malaysia, Singapore, Kalimantan, Sarawak and southern and central Sumatra. Several monitoring stations across the region have recorded unhealthy to hazardous air quality.

Malaysia shuts schools as haze worsens

Malaysia has also been severely affected by the deteriorating air quality.

Around 300 educational institutions in Johor's Batu Pahat district were closed after pollution levels reached the “very unhealthy” category. The Johor government subsequently announced that all schools across the state would close for two days from October 8 as a precautionary measure to protect students.

The decision followed an Air Pollutant Index reading of 203 in Batu Pahat, placing the area in the very unhealthy category. Other parts of Johor, including Segamat, Pasir Gudang, Tangkak, Kluang, Larkin, Kota Tinggi and Pengerang, also recorded unhealthy readings.

Johor Chief Minister Onn Hafiz Ghazi has urged the Association of Southeast Asian Nations (ASEAN) to take a more active role in tackling the regional haze crisis and called for an emergency meeting.

Formula One weekend under scrutiny

The worsening haze comes just as Singapore prepares to host its annual Formula One Grand Prix at the Marina Bay Street Circuit.

Race organisers and the Federation Internationale de l'Automobile (FIA) are monitoring air quality, with concerns centred on public health, visibility and the operation of outdoor activities. The race itself is not currently expected to be affected, but the FIA has said some outdoor entertainment activities could face restrictions if conditions deteriorate further.

Organisers have said they are working with the relevant agencies and will assess the situation before making decisions if the haze creates health, visibility or operational problems. During the 2019 Singapore Grand Prix, when the city also experienced unhealthy haze, organisers had medical assistance available and provided N95 masks to people who needed them.

Health authorities urge caution

Singapore's NEA has advised people to adjust outdoor activity according to pollution levels and individual health conditions.

Healthy people are advised to reduce prolonged or strenuous outdoor exercise when the 24-hour PSI reaches the unhealthy range. Children, older people and pregnant women are advised to minimise such activity, while those with chronic heart or lung conditions are advised to avoid prolonged or strenuous outdoor exertion when the PSI is unhealthy.

The NEA has warned that dry conditions are expected to persist across parts of Sumatra and Kalimantan, with prevailing southeasterly to southerly winds potentially continuing to carry smoke towards Singapore. This means the risk of transboundary haze is expected to remain elevated in the coming days.

The crisis has also renewed scrutiny of Indonesia's management of wildfires and land-clearing practices. Indigenous and civil society groups have filed a lawsuit accusing the Indonesian government of negligence in handling recurring fires, while environmental groups have called for stronger action to protect and restore vulnerable peatlands.