Indonesian Towns and Villages Submerged in Floodwaters

Indonesia flood scene. Credit: Image by Jeffry Surianto, Pexel. 

Between 23 February and 1 March 2026, Indonesia experienced major flooding on 24 February after rivers overflowed, overwhelming communities across Nunukan Regency in North Kalimantan.  

Deep floodwaters of 1-3 m submerged towns and villages, affecting life and infrastructure across the region. 

Key highlights 

• Flooding struck 10 sub-districts in Nunukan Regency after heavy rainfall and waterway overflow.  

• ~4,000 households, involving ~12,500 people, were impacted by high waters.  

• Roughly 30 residents were displaced to emergency shelters for safety.  

• Public infrastructure damage was extensive, including schools, health centres, government offices, businesses, public facilities, and places of worship.  

• The flooding was part of widespread weather extremes in early 2026, including heavy seasonal rainfall across the archipelago. 

Climate Change Context 

Hydrometeorological hazards like floods and cyclone-linked rainfall in Southeast Asia are driven by large-scale climate variability and global warming. Warm sea surface temperatures increase atmospheric moisture, raising the risk of heavier rainfall and flooding in tropical regions. The El Niño–Southern Oscillation (ENSO), a natural cycle of sea surface temperature and atmospheric pressure across the tropical Pacific, strongly affects rainfall patterns in Indonesia, with La Niña typically enhancing wet season rainfall and flood risk.  

Between February 23–March 1, 2026 event in Nunukan Regency, the flooding was linked not only to intense monsoonal rainfall but also to active tropical weather systems in surrounding waters. Regional meteorological monitoring reported tropical disturbances in the Indo-Pacific that can strengthen moisture inflow and prolong heavy rainfall over Indonesia, increasing river overflow and flash flood risks. 

Research also suggests that continued Arctic warming and sea-ice loss may alter global climate systems and contribute to more frequent strong El Niño events by the late 21st century, potentially changing the timing and intensity of ENSO-related rainfall extremes that contribute to events like the February 2026 floods. 

Health and Socioeconomic implications 

• Increased risk of waterborne diseases and sanitation challenges after prolonged floods.  

• Disruption to education as schools were damaged or closed.  

• Healthcare access strained with health facilities damaged or overwhelmed.  

• Economic losses for small businesses, farmers, and transport networks.  

• Displaced families face shelter, food, and livelihood insecurity. 

Urgent response needed 

• Strengthen early warning systems and improve real-time monitoring of heavy rainfall, river levels, and tropical cyclone activity. 

• Invest in flood-resilient infrastructure, including better drainage systems, river embankments, and safe evacuation shelters. 

• Deploy rapid public health and sanitation services to prevent waterborne and vector-borne disease outbreaks. 

• Provide financial and livelihood support for affected households, small businesses, and farmers to accelerate recovery. 

• Scale up climate mitigation and ecosystem protection, including reducing greenhouse gas emissions, protecting forests and mangroves, and promoting nature-based solutions to lower long-term flood risk. 

Read more about extreme weather here. 

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