Heaviest rains in 300 years trigger floods in Thailand, Vietnam, Malaysia
Scientists have long warned that extreme rainfall events are becoming more frequent and intense due to climate change
Large parts of Southeast Asia are battling catastrophic flooding, with Thailand, Vietnam, Malaysia and Indonesia reporting widespread devastation, mounting fatalities, and massive displacement as torrential rains continue to batter the region.
Thailand has been hit hardest, with record floods killing at least 33 people and affecting more than 2 million residents across 10 southern provinces. Hat Yai, a major commercial hub near the Malaysian border, recorded 335 mm of rain in a single day — the heaviest in 300 years.
Photos from the city show submerged buildings and vehicles, while residents stranded on rooftops await rescue. Despite the scale of the disaster, only 13,000 people have been moved to shelters, leaving the vast majority cut off from assistance.
The Thai military, which is leading the response, announced the deployment of:
An aircraft carrier
14 boats with relief supplies
Field kitchens capable of producing 3,000 meals daily
Medical teams ready to convert the carrier into a “floating hospital” if required
Boats, high-clearance trucks and jet skis are being used to rescue stranded residents, according to the governor of Songkhla, where Hat Yai lies. The cabinet has declared the province a disaster zone, freeing emergency funds.
Vietnam has reported 98 deaths in a week, as relentless rains triggered landslides and swelling rivers. In Malaysia, more than 19,000 people have been evacuated, with 126 shelters set up in flood-hit northern states including Kelantan and Perlis. Rescue teams have been wading through knee-deep water to reach stranded residents.
In Indonesia, at least 19 people have died, while seven others remain buried under landslides in north Sumatra, according to the national search and rescue agency.
While seasonal monsoon rains are expected this time of year, meteorologists say Southeast Asia is facing exceptionally severe flooding in 2025, overwhelming infrastructure and emergency resources across the region.
Climate change: The usual suspect
Scientists have long warned that extreme rainfall events like the catastrophic Southeast Asian floods are becoming more frequent and intense due to climate change — a trend repeatedly highlighted by the IPCC (Intergovernmental Panel on Climate Change).
As global temperatures rise, the atmosphere is able to hold significantly more moisture — about seven per cent more for every 1°C of warming — creating conditions for sudden, record-breaking cloudbursts. The IPCC notes that South and Southeast Asia are particularly vulnerable because warming oceans intensify monsoon dynamics, increase evaporation, and fuel slow-moving, moisture-laden storms that dump unprecedented volumes of rain in concentrated bursts.
Urbanisation and deforestation compound these risks, leaving communities exposed when extreme rainfall overwhelms drainage systems and rivers.
The 300-year rainfall record seen in Thailand aligns with these projections: what was once considered a once-in-centuries event is now entering the realm of the “new normal”, driven by a rapidly changing climate and insufficient adaptation measures.