A fire on the surface can be knocked down in an afternoon. The fire underneath it cannot. Once flames reach peat, they drop into a layer of partly decayed plant matter that in Malaysia runs from two metres to 20 metres deep, and embers inside it can smoulder for weeks or months after the surface has gone black and quiet. That is why Sarawak's crews count these operations in days, and why a fire that looks out is often not out.

What is actually on fire when peat burns

Peat is organic matter, waterlogged in its natural state and highly combustible once it dries. In a report published by Bernama on 31 January 2026, Prof Dr Adnan Zainorabidin, head of the Soft Soil Research Centre at the Institute of Integrated Engineering, Universiti Tun Hussein Onn Malaysia, said the layer is rich in flammable organic material and lets hidden embers keep burning after a surface fire appears to have been extinguished. He gave the depth range as two to 20 metres depending on location, and the same report put peat soil moisture content in Malaysia at between 100 and 800 per cent. The practical consequence is that water has to reach the burning layer, not the ground above it.

The Forest Department Sarawak places the state's peat swamp forests immediately behind the coastline, running inland along the lower reaches of the main rivers. On its 2020 figures, 7,721,615 hectares of Sarawak were forested, about 62 per cent of the state's 12,445,000 hectares.

Why eight days is an ordinary number here

Bernama reported on 30 March 2026 that a fire at Kuala Tatau–Serupai in the Bintulu division had reached its eighth day and was under control, with 226 of 300 hectares extinguished. The same day at Kampung Penasu in Daro, Mukah division, a fourth-day operation had put out 10 of roughly 75 hectares, the ground split into three sectors, with 16 personnel assisted by 15 estate workers and 10 residents.

The reports do not agree on the size of the Kuala Tatau–Serupai fire. On 28 March it was given as roughly 400 hectares over six days with 100 hectares controlled, and two days later as 300 hectares in total; burnt-area estimates are revised as crews map the ground.

By 11 April it reported 54 hectares put out across Bintulu and Matu–Daro: a 13-hectare fire on Pulau Bruit had taken eight days, and the largest, near the Igan bridge, had 20 of 35 hectares controlled after ten water-bombing runs by the department's Mi-17i helicopter.

What the Drought Code is telling anyone who reads it

MetMalaysia issues a Fire Danger Rating System daily, adapted from the Canadian forest fire system and implemented regionally after the 1997/98 Southeast Asian haze. Six indices each carry four colour bands:

  • Fine Fuel Moisture Code — ease of ignition in fine fuels such as grass; red above 82.
  • Duff Moisture Code — moisture in the organic surface layer; red above 29.
  • Drought Code — moisture in deep, dense organic matter such as peat; blue below 140, green 140–260, yellow 261–350, red above 350.
  • Initial Spread Index — wind and fine fuel moisture combined, so rate of spread; red above 6.
  • Build Up Index — how much fuel is available to burn; red above 34.
  • Fire Weather Index — the overall difficulty of control; red above 13.

The Drought Code is the one that matters for peat: MetMalaysia describes it as the predictor of fire behaviour in peatland. A high reading does not start a fire. It says that if one starts, it will reach the layer that takes a week to put out.

Who may burn, and what it costs if you may not

The Department of Environment defines open burning as any fire, combustion or smouldering in the open air not directed there through a chimney or stack, other than activities the Minister prescribes by order in the Gazette. Section 29A of the Environmental Quality Act 1974 prohibits it on any premises, including land; section 29B places responsibility on the owner or occupier. Conviction carries a fine of up to RM500,000, up to five years' imprisonment, or both. The department says it finds fires through daily patrols intensified in hot, dry weather, through public complaints, and through NOAA20 satellite hotspot detection.

Who turns up, and what the response depends on

Bernama reported on 27 March 2026 that open fire cases in Sarawak rose sharply from 22 March and peaked at 35 in a single day on 25 March. In the divisional tally published with that report, Miri recorded 59 cases, Sibu 29, Bintulu 24, Mukah 23, Kuching 11, Betong 8 and Sri Aman 5, with Serian, Samarahan, Sarikei and Kapit on three or four each and Limbang none. Tiong Ling Hii, deputy director of the state fire and rescue department, attributed them to agricultural and deliberate burning.

Director-general Datuk Seri Nor Hisham Mohammad said the next day that Sarawak staffing exceeds the national average relative to population, and that surges are met by changing shifts, restricting leave and moving personnel between stations, and that enforcement has to run in step with local authorities, the Department of Environment and the Natural Resources and Environment Board. Satellite monitoring flags likely hotspots, but the most reliable early warning is still a report from the public. Three new fire stations were under construction: Sungai Asap in Belaga, Engkelili in Sri Aman and Dalat in Mukah.

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