Thailand’s Meteorological Department (TMD) has placed multiple provinces on high alert as heavy monsoon rains sweep across the country, raising the risk of flash floods, overflowing rivers and dangerous sea conditions.
The department reported that the monsoon trough remains strong over northern and northeastern Thailand, with southwesterly winds driving moisture from the Andaman Sea and Gulf of Thailand. Thunderstorms are forecast across most regions, with certain provinces expected to experience intense downpours. Authorities have urged residents, particularly in low-lying and foothill areas, to remain vigilant for sudden flooding and landslides.
Rising flood risk and rough seas
The TMD warned that accumulated rainfall could overwhelm rivers and drainage systems, heightening the possibility of flash floods. Coastal areas are also bracing for rough conditions, with waves in the upper Andaman Sea expected to reach between 1 and 2 metres, surging above 2 metres in stormy weather. The Gulf of Thailand and lower Andaman region may also experience waves of up to 2 metres during thunderstorms.
Mariners have been strongly advised to avoid storm-prone zones and small boats are urged to stay ashore until conditions improve. Fishing communities, tourist operators and shipping routes are expected to be affected, particularly in provinces such as Phuket, Krabi, Ranong and Songkhla.
Regional forecasts across Thailand
According to the TMD, northern provinces including Chiang Mai, Chiang Rai, Nan and Phitsanulok will see widespread thunderstorms and isolated heavy showers. The northeast, covering Nong Khai and Bueng Kan, is forecast to have scattered thundershowers, while central provinces such as Nakhon Sawan and Ayutthaya will also face unsettled weather.
Eastern provinces including Chanthaburi and Trat should prepare for rough seas, while both east and west coasts in the south — covering Surat Thani, Songkhla, Krabi and Trang — are forecast to face thunderstorms with high waves.
Bangkok and surrounding areas will not be spared, with scattered thundershowers expected, although temperatures are set to remain within 24°C to 34°C.
Authorities call for vigilance
Officials have stressed that people living near rivers, canals and hilly terrain must prepare for sudden water surges. Emergency services have been placed on standby across several regions.
The TMD emphasised that the public should closely monitor weather updates and avoid unnecessary risks, especially in areas where floodwaters can rise quickly. With the monsoon season still in full swing, Thailand remains on high alert for more heavy rainfall in the coming weeks.