Smoke from peatland fires covered large parts of Kalimantan for much of August and September 2026. It cut visibility at airports and pushed up respiratory illness across Indonesian Borneo. In Palangka Raya, the capital of Central Kalimantan, the city health office recorded 9,324 cases of acute respiratory infection (ARI) between June and September. Cases peaked in August at 3,104.

Kalimantan peatland fires are usually reported as an environmental story about carbon emissions. For the people living under the smoke, they are a health and income crisis that comes back in most dry seasons. This year, El Niño conditions lengthened the drought, and land clearing provided the ignition, according to Indonesia's forestry ministry as reported by ABC News.

What are peatland fires?

Peat is a thick layer of partly decomposed plant material. It builds up over thousands of years in waterlogged swamp forests, and Kalimantan has large areas of it. When peat is drained for plantations or farming, or dries out during a long drought, it can catch fire.

Peat fires do not stay on the surface. They spread into the ground and can smoulder for weeks, producing dense, low-lying smoke. Firefighters often cannot reach the burning layer, so many fires only go out after sustained rain.

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How large were the 2026 fires?

More than 202,000 hectares burned across Indonesia between January and June. Nearly 95,000 more hectares burned in July, mostly in Sumatra and Kalimantan, according to government figures reported by ABC News.

West Kalimantan was the worst affected province. By 15 September, the National Disaster Management Agency (BNPB) had recorded 48,535 hectares burned there, based on satellite data and field measurements. In mid-September, visibility in Pontianak and Ketapang fell below one kilometre.

Earlier in the season, visibility had dropped to 400 metres at Syamsudin Noor Airport in South Kalimantan and 1.2 kilometres at Supadio Airport in Pontianak. Those readings were taken on 19 August and cited in a Human Initiative situation report.

The smoke also crossed borders, reaching Malaysia, Singapore, Brunei and the Philippines.

Rain and weather modification operations have since reduced the fires. On 28 September, BNPB reported that 96 hectares were still burning across its six priority provinces, which include Central, South and West Kalimantan.

Why the haze is a humanitarian problem

Health. Haze carries fine particulate matter (PM2.5). These particles are small enough to reach deep into the lungs and enter the bloodstream. The risk is highest for young children, older people, pregnant women and people with heart or lung conditions.

Between 7 and 11 August, 2,052 ARI cases were recorded across 14 districts and cities in Central Kalimantan, according to Human Initiative's situation report. Riduan, head of the Palangka Raya health office, said this year's total was still well below the major haze seasons of the 2000s.

School and work. When the smoke thickens, local governments suspend classes and outdoor work becomes difficult. Pontianak suspended in-person schooling in mid-August [TO CONFIRM]. Farmers, labourers and street vendors who are paid by the day lose income on every day they cannot work.

Livelihoods. The fires also burn smallholder fields and the forest that rural and Indigenous communities depend on for food and income. Peat that has burned once dries out further and is more likely to burn again unless it is rewetted.

How Human Initiative is responding

Human Initiative reported on 22 August that its teams had:

• coordinated with local authorities and partners in four Kalimantan provinces
• carried out needs assessments
• distributed masks to children, older people, pregnant women, people with disabilities and people with respiratory illness
• provided health checks and hygiene education at Pondok Pesantren Mathla'ul Anwar, an Islamic boarding school in Pontianak

What happens next

Some areas are still under emergency status. Sukamara district in Central Kalimantan extended its fire emergency in early October after recording 651 ARI cases [TO CONFIRM figure, period and end date of emergency]. Relief is expected when the rainy season sets in over the coming weeks. Health workers will keep watching for respiratory cases until the air clears.

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Support the response: Human Initiative is supporting families affected by the Kalimantan haze with masks and health services. Donate for Kalimantan Haze Relief