HAT YAI, THAILAND – Record-breaking rains and surging floodwaters left southern Thailand struggling with one of its worst natural disasters in years.
Disaster agency issues urgent alerts
The national disaster prevention agency DDPM issued high-level warnings for 20 districts in Nakhon Si Thammarat, where authorities feared extreme rainfall, flooding and landslides. The alert was sent via cell broadcast in cooperation with mobile operators AIS, True and NT to residents in Muang, Thasala, Phromkhiri, Lansaka and other hard-hit areas. People were told to move valuables to safety, avoid electrical hazards and stay away from unstable slopes, canals and riverbanks, with particular attention to older people, the sick and children.
“Stay vigilant – it can get worse at any time!”
said the DDPM.
Millions affected across southern provinces
Conditions deteriorated across the wider region, with 1.9 million people in 10 provinces reported affected by the flooding. Entire districts in Surat Thani, Krabi, Songkhla, Trang, Satun, Pattani, Yala and Narathiwat were under water. In around 4,100 inundated villages, residents battled the floods, often without power and unsure whether help would arrive in time.
Overwhelmed communities and rising waters
In many locations, water levels continued to rise even as emergency shelters were already overcrowded. Experts warned that a low-pressure system over the south could bring further heavy rain. As a result, thousands of people spent the night on rooftops, tables or upper floors, waiting desperately for rescue.
Hat Yai hit by historic downpour
In Hat Yai, the main city of Songkhla province, authorities reported a historic deluge. According to the Smart Water Operation Center, 335 millimetres of rain fell there on 21 November, the heaviest recorded in 300 years. For days, additional runoff from surrounding mountains had been pushing into the city, driving a relentless rise in the level of the U-Taphao canal.
Canal levels turn districts into lakes
Experts expected the U-Taphao canal to reach between 1.25 and 1.45 metres on 25 November, a range that had already turned entire neighbourhoods into lakes. Officials described the situation as a “high-level evacuation warning,” while accounts on social media pointed to mounting frustration and fear among residents.
“We are screaming for help – but no one comes.”
said residents online, according to the authorities.
Three drivers behind the “mega-flood”
Environmental researcher Sonthi Kotchawat said the south was facing one of its most severe natural disasters in years, with all 16 districts of Songkhla under water and damage already exceeding 1.5 billion baht. He cited three main factors for the scale of the crisis: low-lying geography that channels water through Hat Yai toward Songkhla Lake, extreme weather patterns and inadequate preparation.
“This is one of the worst natural disasters in years.”
said Sonthi Kotchawat, environmental researcher.
Geography, weather and weak preparedness
Hat Yai’s low elevation and drainage system toward Songkhla Lake failed once levels rose beyond capacity. La Niña conditions, a high-pressure system from China and a strong monsoon trough combined to produce historically intense rainfall. Despite prior warnings, emergency plans remained incomplete and response teams overstretched, leaving many communities exposed.
Bottlenecks at Khao Kho Hong
The impact was worsened by this year’s rains over Khao Kho Hong, an area whose runoff cannot pass through the relieving R1 canals. Instead, the water flowed directly into Hat Yai, further increasing the pressure on already flooded districts and straining drainage infrastructure.
Chaotic evacuations in Songkhla
As conditions worsened in Hat Yai, desperate calls echoed through the city’s streets.
“We need boats! We need help!”
said residents during the night, according to local accounts. When Songkhla governor Ratthasart Chidchoo ordered a full evacuation, many people were already trapped in buildings.
Rescue capacity under strain
Hundreds of residents, including bedridden patients, children and older people, remained stranded without adequate supplies. The army and navy deployed boats, trucks and helicopters from the aircraft carrier HTMS Chakri Naruebet, but the scale of need outstripped available resources. By Tuesday, the DDPM reported 2.19 million people affected and rising water levels in nine southern provinces, with no clear end to the disaster in sight.
North and central regions also at risk
While the south was submerged, authorities also reported flooded provinces in the north and central regions, from Phitsanulok to Ayutthaya and from Uthai Thani to Nakhon Pathom. In many of these areas, water levels had started to recede, but Phitsanulok remained steadily inundated.
Meteorologists warn of more heavy rain
Meteorologists warned that heavy rainfall could continue until Wednesday before conditions might improve. Until then, officials and residents across the affected regions faced days of endurance, rescue operations and uncertainty, holding out hope that the waters would begin to fall.