Indonesia Races to Contain Wildfires as El Niño Peaks Over Kalimantan

Indonesia has made Kalimantan its top priority for wildfire response as fire hotspots climb through August 2026. The national disaster agency expects the peak of this year's El Niño — a warming of Pacific Ocean surface temperatures that shifts weather patterns worldwide — to hit Central Kalimantan between August and September (Reuters).

BNPB, Indonesia's National Disaster Management Authority, set an official fire-handling period (known locally as karhutla, short for karhutla or land and forest fires) in Central Kalimantan from 26 May through 31 October 2026. That window brackets the months when dry-season conditions are most likely to ignite peat deposits and standing vegetation (BNPB). Indonesia's weather agency expects the El Niño episode to persist into early 2027, extending the window of elevated fire risk well beyond a single dry season (Reuters).

The scale of burning has already outpaced earlier in the year. Land and forest fires consumed 107,465 hectares (265,552 acres) across Indonesia from January through June 2026 — a 110% increase as El Niño intensified (Reuters). July alone saw nearly 95,000 hectares burned, almost doubling the cumulative damage from the preceding six months (Reuters).

Hotspot data tracked the acceleration. NASA's NOAA-20 satellite recorded 46 hotspots in South Sumatra on 2 August 2026, a figure that climbed to 104 the following day (BNPB). New fire incidents have surfaced beyond Sumatra and Kalimantan: BNPB reported a karhutla event in Aceh Besar Regency, Aceh Province, on 30 July 2026 (BNPB).

BNPB has framed the 2026 El Niño and concurrent dry season as drivers of compound risk: drought, forest and land fires, and clean water crises across the archipelago (BNPB). Environmental groups share that concern. Civil society organisations warn that drier El Niño conditions could trigger renewed peatland fires across Borneo and Sumatra (Mongabay).

Indonesia's peatlands are the geophysical factor that turns a seasonal dry spell into an internationally consequential fire event. Peat is partially decayed plant matter that accumulates in waterlogged environments over thousands of years. Even a moderate El Niño can dry the landscape enough to prime it for combustion (NASA). When thick peat deposits, El Niño weather patterns, and economic development activity converge, the resulting fires release enormous volumes of planet-warming emissions, as documented during previous severe fire seasons (NASA Earth Observatory). Peat fires burn below the surface, making them unusually difficult to suppress once ignited, particularly across Sumatra and Borneo (NASA Earth Observatory).

The trajectory of the 2026 fire season bears structural parallels to those earlier episodes. The first half of the year already produced a 110% jump in burned area over the previous year, and July's near-doubling of that total indicates the burn rate is accelerating as El Niño approaches its forecast peak. BNPB's operational window, running through 31 October, is designed to cover the most dangerous months, but the weather agency's projection that El Niño will last into early 2027 raises the possibility that fire conditions could extend beyond the agency's declared handling period.

The prioritisation of Kalimantan also reflects where the risk is concentrated geographically. Central Kalimantan holds extensive peat deposits that, once dried, become subsurface fuel sources invisible to conventional suppression tactics. Reuters reported on 21 August that Indonesia had elevated Kalimantan as its response priority, a decision that aligns with BNPB's July forecast of an August-to-September El Niño peak in the province.

The broader context here is what will determine whether the 2026 season approaches the severity of the 2015 episode, which NASA characterised as producing grim, planet-warming emissions on a remarkable scale. The duration and intensity of El Niño conditions through the remainder of 2026 is the primary climatic variable. The effectiveness of BNPB's coordinated response, including weather modification operations — essentially cloud-seeding to induce rainfall — of the type already deployed in South Sumatra, will shape how quickly emerging hotspots are contained before they spread into peat layers. And the degree to which local economic activity, including land clearance practices, intersects with dried peatlands will influence ignition rates independently of broader climatic conditions.

For regional governments and international observers, the indicators to watch are hotspot counts, burned-area totals through the August-to-September peak, and any transboundary haze affecting neighbouring Southeast Asian states. Indonesia's handling period formally closes on 31 October, but the weather agency's forecast that El Niño persists into early 2027 means the operational calendar may not fully capture the risk window.