2025 Southeast Asia floods and landslides

Since September 2025, floods and landslides have struck heavily in Southeast Asia and partly in nearby South Asia regions.^[1] The crisis peaked in November 2025, triggered by the rare and powerful Tropical Cyclone Senyar, as well as other simultaneous cyclonic systems amid Northeast Monsoon and La Niña conditions.^[2][3]

The disaster was recorded as one of the deadliest natural disaster events in Southeast Asia in 2025.^[4][5] The combined impact of Cyclone Senyar and other associated storms resulted in a total of over 798 reported deaths in Indonesia, Thailand, and Malaysia. The overall death toll across the affected region (including the Philippines, Vietnam, and Sri Lanka) exceeded 900 people, with thousands missing and millions directly affected.^[6][7][8]

Experts and international bodies explicitly linked the exceptional intensity of the disaster as "the latest example of the impact of the climate crisis on storm patterns and extreme weather."^[9] Furthermore, analyses indicate that the disaster was aggravated by non-climate factors, particularly large-scale deforestation and poor land management in hilly areas, which increased vulnerability to deadly landslides.^[10][11]

The peak of the crisis in Southeast Asia was triggered by Tropical Cyclone Senyar, a rare cyclone that formed in the Malacca Strait in November 2025. Senyar originated from a low-pressure area on November 22 and intensified into a deep depression on November 25. On November 26, the system was named Cyclone Senyar by the India Meteorological Department (IMD), with maximum wind speeds reaching 43 knots or about 80 km/h.

Cyclone Senyar moved across the Malacca Strait and made landfall in northeastern Sumatra near midnight on 25 November. Although its development was limited due to its proximity to land, the system brought heavy rainfall and flash floods to Sumatra, Southern Thailand, and the Malay Peninsula. Senyar is the second documented tropical cyclone in the Malacca Strait after Tropical Storm Vamei in 2001. After crossing the Malay Peninsula and making a second landfall in Selangor, the remnants of the storm re-emerged in the South China Sea on 28 November and regenerated.

This event occurred amid the Northeast Monsoon season and atmospheric conditions were supported by the La Niña phenomenon, which was predicted to continue until early 2026 and correlates with above-average rainfall in Southeast Asia.

In addition to Cyclone Senyar, the regional crisis was exacerbated by:

• Cyclone Ditwah which caused large-scale disaster in Sri Lanka.
• Typhoons Kalmaegi (Tino) and Fung-Wong (Uwan) which successively hit the Philippines in less than a week.

Rainfall anomalies were recorded as extremely severe. The city of Hat Yai in Songkhla Province, Thailand, recorded a rainfall amount of 335 millimetres (13.2 inches) in a single day on 21 November, reported as the heaviest amount recorded in a single day in the last 300 years in the region.

The 2025 disaster was exacerbated by internal, human-created vulnerabilities. Environmental damage, including deforestation and illegal mining activities, were cited by experts as contributing factors that worsened the impact of the disaster. In Sumatra, the loss of millions of hectares of forest over the last twenty years has eliminated the natural water retention and absorption system, which converted heavy rain into deadly flash landslides.

The total death toll from Cyclone Senyar across three countries (Indonesia, Thailand, Malaysia) reached at least 1,107 people.

Indonesia experienced the country's deadliest natural disaster since the 2018 Sulawesi earthquake and tsunami, with 604 people dead, 464 missing, and 2,600 injured due to Cyclone Senyar.^[17] A total of over 1.1 million people were affected, with 570 thousand people displaced across the three main provinces.^[18]

• North Sumatra: 283 fatalities, with the worst impact in Central Tapanuli Regency (47 deaths, 51 missing) and Sibolga City (33 deaths, 56 missing).
• West Sumatra: 165 fatalities, including 120 people killed by flash floods in Agam Regency. A landslide at the entrance gate of Padang Panjang killed 30 people.
• Aceh: 156 fatalities, 1,614 injuries, and 116 others missing. Around 46,000 homes were damaged. Power outages occurred in parts of Aceh due to a 150 KV transmission tower collapsing from the flash flood.^[19]

Infrastructure damage was extensive; major road access, such as the Tarutung-Sibolga Road, was completely paralysed due to 3-metre-deep floods and burial by landslides. Several PLN (state electricity company) power infrastructure facilities were also damaged.

Malaysia experienced two significant incidents. An incident in September 2025 in the state of Sabah has caused landslides and flash floods, killing 13 to 14 people and displacing 3,325 people.^[20][21] The second period in November, due to Cyclone Senyar, brought major flooding to Peninsular Malaysia, leading to the evacuation of over 34,000 people across 10 states. Two people were reported dead due to flooding in Kelantan.^[22]

Flooding due to Cyclone Senyar and the intensified Northeast Monsoon affected 3.6 million people in 20 provinces across Thailand, particularly in the Southern region. At least 263 fatalities were reported in the country, with 200 of these concentrated in Songkhla Province, which was declared a disaster zone. Other reports from rescue workers indicated the death toll in Songkhla was closer to 550 to 1,000 lives.

The worst impact occurred in the city of Hat Yai, Songkhla. Extreme rainfall (335 mm in one day) caused floods reaching a depth of 2 meters, stranding 7,000 foreign tourists and damaging religious sites, such as the Mahattamangkalaram temple, which was submerged under 16 feet of water. Economic damage from the floods in Thailand was estimated at 100 billion baht (US$3.11 billion).

In late September and early October, the 2025 Northern Vietnam floods caused by the combination of typhoons Ragasa, Bualoi, and Matmo, together with other rain-inducing weather systems, resulted in 85 deaths and missing persons – 67 during Bualoi^[13] and 18 during Matmo.^[14]

In late October and early November, the first period of 2025 Central Vietnam floods caused at least 66 deaths and missing following days of flooding and landslides, along with Typhoon Kalmaegi.^[15] In late November, the second period flooding in South Central Vietnam killed 98 people, 10 others missing and damage reached 14.352 trillion dong (US$571 million).^[16]

The Philippines faced successive strikes from Typhoon Kalmaegi (Tino) and Super Typhoon Fung-Wong (Uwan) in November. Collectively, these storms resulted in more than 283 deaths and over 100 people missing. The disaster affected approximately 13 million people and led to class suspensions impacting around 17 million students. However, an effective early warning system allowed for the mass precautionary evacuation of over 1.5 million people.

In response to the scale of the disaster, the Indonesian government immediately deployed massive aid, including three C-130 Hercules aircraft and one A-400 from the President of Indonesia, as well as a total of 6 tons of logistics from the Indonesian National Police (Polri) using Fokker 50 and CN295 aircraft. The Ministry of Social Affairs (Kemensos) distributed Rp 2.6 billion in aid and established emergency tents and public kitchens. The Regional Disaster Management Agency (BPBD) provided emergency aid in the form of basic necessities (sembako), family kits, kitchen kits, refugee tents, and rubber boats.

As a technological support measure, Elon Musk's Starlink satellite internet service was provided free of charge to flood and landslide victims in Sumatra and Sri Lanka until the end of December 2025.

In Thailand, the Royal Navy deployed 14 vessels, including the aircraft carrier HTMS Chakri Naruebet, to provide aid supplies and medical personnel. Internationally, India provided 10 tons of emergency assistance to Sri Lanka under Operation Sagar Bandhu, including disaster response supplies and medical teams.

• Tropical cyclones in Indonesia
• Cyclone Senyar
• Sumatra floods and landslides 2025
• Typhoon Fung-wong (2025)

• Indonesian Agency for Meteorology Climatology and Geophysics (BMKG)
• Joint Typhoon Warning Center