Early Peat Fires Sparked by El Niño Accelerate Indonesia's 2026 Fire Season

Indonesia is facing an early rise in underground peat blazes as the 2026 fire season gets underway, driven by a strengthening El Niño and a severe drought that has left wetlands bone‑dry. Satellite data collected this month reveal a pronounced increase in hot spots across Sumatra, Kalimantan and Papua, showing that fires are taking hold beneath the surface weeks before the usual seasonal peak.

Peatlands, made up of centuries‑old organic material, are especially vulnerable to smoldering combustion. A drop in the water table dries the peat, allowing it to ignite without visible flames and to burn below ground for weeks or even months. This concealed behavior makes detection and suppression challenging, while the slow, oxygen‑starved burn releases large amounts of fine particulate matter and volatile organic compounds that are far more hazardous than the smoke from surface fires.

The stakes for health and the environment are considerable. Fine particles (PM2.5) produced by peat fires can travel hundreds of kilometres, degrading air quality in major Indonesian cities and neighboring nations. Residents report a rise in respiratory problems, and the haze has forced school closures and cut labor productivity. Climate‑wise, the carbon locked in peat—estimated at up to 30 percent of global soil carbon—is rapidly emitted, adding a powerful source of greenhouse gases to an already warming atmosphere.

Traditionally, Indonesia’s fire season reaches its height between August and October, when the dry spell coincides with land‑clearing practices. This year, however, an early‑starting drought combined with an unusually strong El Niño has moved the timeline forward, permitting fires to spark as early as May. Comparisons with the 2015 and 2019 crises—both marked by severe haze—indicate that the present conditions could generate a similarly extensive, if not larger, impact should containment efforts falter.

Authorities have deployed fire‑fighting crews, aerial water drops, and community alert systems, yet the subterranean nature of peat combustion curtails the efficacy of standard suppression methods. International agencies are keeping watch, and scientists emphasize that restoring peat hydrology—through re‑wetting initiatives and stricter land‑use enforcement—remains the most dependable long‑term mitigation approach. As the season unfolds, the path of these hidden fires will dictate regional air quality, public‑health outcomes, and Indonesia’s role in global carbon emissions.