Monsoon brings heavy rains across Thailand, authorities warn of flood risks

The monsoon is expected to bring isolated heavy rains to the upper regions of the country, with very heavy rains likely in the North and Northeast.

The monsoon trough has shifted northward, now lying across the upper North of Thailand and extending into upper Laos, connecting with a low-pressure system over upper Vietnam, the Thai Meteorological Department forecast on Friday. 

Meanwhile, the moderate southwest monsoon continues to dominate the Andaman Sea, Southern Thailand, and the Gulf of Thailand, it added.

This weather pattern is expected to bring isolated heavy rains to the upper regions of the country, with very heavy rains likely in the North and Northeast. The department warned the public to be cautious of heavy to very heavy rainfall and water accumulation that could cause flash floods and overflows, particularly near waterways, foothills, and lowland areas.

Farmers are advised to improve drainage systems in agricultural areas to reduce potential damage to crops and livestock.

The moderate winds over the upper Andaman Sea are generating waves reaching up to 2 metres in height, while waves in the lower Andaman Sea range between 1 to 2 metres. During thunderstorms, waves can exceed 2 metres, the department said.

All vessels operating in the Andaman Sea and the Gulf of Thailand are urged to exercise caution and avoid thunderstorm areas. Small boats in the upper Andaman Sea are advised to remain ashore until conditions improve.

Additionally, the active low-pressure cell near the coast of India is expected to weaken soon, minimizing its impact on Thailand’s weather.
Residents and travelers are advised to stay updated on weather developments and take necessary precautions during this period.

The weather forecast for the next 24 hours is as follows:

North: Fairly widespread thundershowers and isolated heavy to very heavy rains in Mae Hong Son, Chiang Mai, Chiang Rai, Lamphun, Lampang, Phayao, Phrae, Nan, Uttaradit, Tak, Phitsanulok, and Phetchabun; minimum temperature 24-25 degrees Celsius, maximum 30-34°C. 

Northeast: Fairly widespread thundershowers and isolated heavy to very heavy rains in Loei, Nong Bua Lamphu, Udon Thani, Nong Khai, Bueng Kan, Sakon Nakhon, Nakhon Phanom, Chaiyaphum, Khon Kaen, Maha Sarakham, Kalasin, Mukdahan, Roi Et, Yasothon, Amnat Charoen, and Nakhon Ratchasima; minimum 23-25°C, maximum 32-34°C.

Central: Scattered thundershowers and isolated heavy rains in Kanchanaburi, Ratchaburi, Lopburi and Saraburi; minimum 26-28°C, maximum 33-35°C. 

East: Fairly widespread thundershowers and isolated heavy rains in Nakhon Nayok, Prachin Buri, Sa Kaeo, Chachoengsao, Chonburi, Rayong, Chanthaburi and Trat; minimum 24-28°C, maximum 32-34°C; waves about a metre high and above 2 metres high in thundershowers.

South (east coast): Isolated thundershowers mostly in Phetchaburi, Prachuap Khiri Khan, Chumphon, Yala and Narathiwat; minimum 26-27°C, maximum 32-35°C; waves about a metre high and above 2 metres high in thundershowers.

South (west coast): Isolated thundershowers mostly in Ranong and Phang Nga; minimum 26-27°C, maximum 32-35°C; waves about 1-2 metres high and above 2 metres high in thundershowers.

Bangkok metropolitan area: Fairly widespread thundershowers and isolated heavy rains; minimum 25-28°C, maximum 32-35°C.

(2025/05/30-00:00)