Cyclone Seroja (2021)
In early April 2021, Tropical Cyclone Seroja did what tropical cyclones almost never do near Indonesia — it struck the country directly, devastating the southern islands of East Nusa Tenggara with catastrophic floods and landslides.
Why Seroja was unusual
Most of Indonesia is too close to the equator for tropical cyclones to form or reach. But the southernmost islands, near Timor, lie far enough south to sit at the edge of the cyclone-prone zone. Seroja formed in that fringe and, unusually, tracked right across populated islands rather than staying out at sea.
The disaster
As Seroja developed and moved through the region around 4–5 April 2021, it unleashed torrential rain across East Nusa Tenggara. On islands including Flores, Adonara, Lembata, and Timor, the downpours triggered flash floods and landslides that buried homes and swept away entire communities. More than one hundred and fifty people were killed, with many others missing, and tens of thousands were displaced. The storm went on to affect parts of neighbouring Timor-Leste and, later, Western Australia.
Why it was so deadly
- A rare hazard in an unprepared region. Communities with no history of cyclones had little reason to expect one.
- Steep, saturated terrain. Torrential rain on hilly islands produced fast, deadly landslides.
- Remote geography. Scattered islands made warning and rescue difficult.
The lesson
Seroja is Indonesia's equivalent of the rare near-equator cyclones that surprise this part of the world — much as Typhoon Vamei stunned the region near Singapore in 2001. It underlined that while the equator protects most of Indonesia from typhoons, the far southern islands must plan for the rare but devastating exception. See more on why Indonesia so rarely gets cyclones.