Smoke from fires in Indonesia closed schools across much of Peninsular Malaysia on Friday, Oct. 9, affecting roughly 2 million students, while Singapore's 24-hour Pollutant Standards Index reached its highest level in 2026. Singapore's National Environment Agency recorded a 24-hour PSI of 192 in the central region between 5 p.m. and 8 p.m. local time on Oct. 9, near the top of the "unhealthy" band.

Malaysia ordered schools closed in Kuala Lumpur, Putrajaya, Johor, Malacca, Negeri Sembilan and Selangor, along with the Rompin district of Pahang, Al Jazeera reported. Affected schools were directed to switch to home-based teaching.

The haze is a regional public health problem — not a local one. Fine smoke particles can travel hundreds of miles, and the same plume is affecting millions of people in two countries that did not start the fires, raising pressure for a coordinated response through the Association of Southeast Asian Nations.

Readings Across Malaysia and Singapore

Malaysia's Department of Environment reported unhealthy readings in dozens of areas. Segamat in Johor recorded an Air Pollutant Index of 190 on Thursday, Oct. 8, according to Outlook India, and Kuala Lumpur's reading was about 170, Al Jazeera reported. Malaysia classifies readings of 101 to 200 as unhealthy and above 300 as hazardous.

In Singapore, the National Environment Agency said at 7 p.m. on Oct. 10 that "moderate to dense smoke haze from southern Sumatra was observed to drift towards Singapore," The Straits Times reported. The 24-hour PSI peaked at 183 in the central region that day, and one-hour PM2.5 levels in the central region briefly reached the "high" band at 151 micrograms per cubic meter.

The agency forecast that the 24-hour PSI on Oct. 11 would stay in the unhealthy to high unhealthy range, below the "very unhealthy" band of 201 to 300. The worst one-hour PM2.5 reading of this haze episode so far was 171 in the west on Oct. 9.

Fires in Sumatra and Kalimantan — fueled by hot, dry conditions — are the source. Al Jazeera, citing its correspondent, said fires have burned across six Indonesian provinces and scorched at least 200,000 hectares (about 494,000 acres), in what it described as Indonesia's worst fire season in more than a decade. Indonesia's Health Ministry has recorded more than 170,000 respiratory infections, a count limited to people who sought care.

Leaders Press for an ASEAN Response

Malaysian Prime Minister Anwar Ibrahim said "The haze issue is indeed at a worrying level," and that Indonesian President Prabowo Subianto agreed to take necessary steps, though he gave no details. Anwar asked Malaysia's foreign minister to seek an urgent meeting of ASEAN environment ministers, and Malaysia is expanding cloud seeding to try to induce rain.

Malaysia's King, Sultan Ibrahim, called for protections for schoolchildren, older people and people with respiratory illnesses, and said schools should close when readings reach 150 or higher, Al Jazeera reported. Education Minister Fadhlina Sidek said the ministry would announce future closure decisions earlier so parents can plan.

Singapore has prepared steps for worse conditions. If the 24-hour PSI exceeds 200, N95 masks will be distributed to eligible residents and preschools must stop outdoor and strenuous indoor activities. Education Minister Desmond Lee said lessons and national exams would continue in enclosed rooms with air purifiers, and that school closures would be considered only if forecasts exceed a PSI of 300.

Organizers said the Formula 1 Singapore Grand Prix, held Oct. 9 to 11, would go ahead with masks and extra medical staff on hand.

Health Risks and Who Faces Them

The greatest health risk falls on children, older adults, pregnant people and anyone with heart or lung disease. Singapore's agency advises healthy people to reduce prolonged or strenuous outdoor activity when the PSI is unhealthy, and vulnerable groups to minimize or avoid it. When one-hour PM2.5 readings reach the high band, everyone should avoid strenuous outdoor activity.

Practical steps include staying indoors with windows closed, running air purifiers with HEPA filters where available and wearing well-fitted N95 masks outdoors. People who develop chest pain, severe shortness of breath or worsening asthma should seek medical care promptly.

The same exposure matters for U.S. readers who live with wildfire smoke. Smoke particles of this size are the main health concern in American smoke events, and similar precautions apply when local air quality alerts are issued in the West.

A Fire Season Shaped by Drought and El Niño

Indonesian officials warned in August that El Niño conditions threatened more fires during the dry season, Al Jazeera reported. El Niño typically brings drier weather to much of Indonesia, and fires on drained peatlands can smolder underground and reignite even after hotspot counts fall.

Outlook India reported that Indonesia recorded a recent drop in hotspots, but environmental groups cautioned that peat fires can persist. Forecasts for wind direction will determine whether the smoke continues to blow toward Malaysia and Singapore.

Several questions remain open, including when all Malaysian schools will fully reopen, whether ASEAN ministers will meet, and how quickly rains will arrive. Singapore issues daily haze forecasts at 7 p.m. local time, and Malaysia's Department of Environment posts hourly readings.

The bottom line is that smoke from Indonesian fires has pushed air quality to unhealthy levels across a densely populated region, closing schools and setting a 2026 high in Singapore. Residents should check official readings before going outside and take extra care with children and older relatives until the haze clears.

What Readers Want to Know

What is causing the haze?

Smoke from fires in Indonesia's Sumatra and Kalimantan regions, driven by hot, dry conditions, is drifting across Malaysia and Singapore.

How many students were affected in Malaysia?

About 2 million students were affected when schools closed on Oct. 9 in Kuala Lumpur, Putrajaya, Johor, Malacca, Negeri Sembilan, Selangor and part of Pahang.

How bad is Singapore's air?

The 24-hour PSI reached 192 in the central region on Oct. 9, the highest of 2026, within the unhealthy range of 101 to 200.

Who is most at risk?

Children, older adults, pregnant people, and people with heart or lung disease face the greatest risk from fine smoke particles.

How can people protect themselves?

Stay indoors with windows closed, use air purifiers if available, wear N95 masks outdoors and avoid strenuous outdoor activity when readings are unhealthy.

When will the haze end?

That depends on rain and wind direction. Singapore's NEA forecast unhealthy readings to continue on Oct. 11, and officials update forecasts daily.