Smoke from fires burning across Indonesia – which are being enhanced by El Niño – has arrived over Australia’s northwest coast this week.

Indonesia ablaze under El Niño’s influence

Seasonal fire activity in Indonesia is being made more intense and widespread this year by the drying influence of El Niño. When El Niño is underway, trade winds weaken or reverse over the tropical Pacific, resulting in less moisture-laden air flowing towards Indonesia and northern Australia.

This drying influence has been evident over the last three months as El Niño became established in the tropical Pacific. The map below shows that rainfall was below average over Indonesia and above average across the tropical Pacific during the June-to-August period this year. This is a typical rainfall footprint of a strengthening El Niño.

The dry conditions over the last few months caused a rapid increase in fire activity in Indonesia and other parts of the Maritime Continent.

Some of the fires in Indonesia in recent weeks are likely burning through tropical peatlands that have been drying out in the last few months. Peat fires can be difficult to extinguish because they smoulder slowly underground, creating large volumes of smoke for prolonged periods.

The map below shows where NASA’s Terra and Aqua satellites detected fire hotspots with high confidence in Indonesia during the first week of September.

Image: Fire hotspots in Indonesia during the first week of September. Source: SIPONGI KEMENFUT.

According to data from Indonesia’s Ministry of Forestry fire monitoring program, SiPongi, this appears to be the most active fire season since at least 2019 based on hotspot data.

Smoke from the fires in Indonesia has been drifting across southeast Asia and the eastern Indian Ocean in recent weeks. Visible satellite images reveal that some of the smoke has even made it to the Australian mainland around Broome on Western Australia’s Kimberley coast. This smoke could be seen from the ground as a haze on the horizon.

Image: Smoke from fires in Indonesia being blown towards northern Australia on Wednesday, September 9, 2026. Source: Weatherzone.

How long will the fires last?

Indonesia’s fire season typically runs from around July to October, with the most intense burning usually happening in September and October before the wet season rainfall arrives from October or November.

With El Niño still gaining strength in the Pacific Ocean, fires are likely to remain active across Indonesia for several more weeks at least. This may include smoke plumes periodically drifting over parts of northern Australia in the next couple of months.