Thailand Braces for Heavy Rain Alert Through Aug 21
Thailand's meteorological department issued its fifth heavy rain alert through August 21, warning of severe flooding across the North and Northeast as a monsoon trough intensifies rainfall and a vigorous southwest monsoon generates waves up
The Thai Meteorological Department announced on August 17 its fifth heavy rain alert (Warning 159/2026) for August 18-21, affecting predominantly the North and Northeast as a monsoon trough sweeps across these regions combined with a vigorous southwest monsoon over the Andaman Sea and Thailand. Residents are warned to watch for severe to very heavy rainfall and accumulated precipitation that may cause flash floods and mudslides, especially in foothill and low-lying areas. Travel through flood-prone routes, particularly in basins, should be avoided as water may accumulate rapidly. Strong winds and high waves of 2-3 metres are forecast for the upper Andaman Sea from August 19-21, exceeding 3 metres in thunderstorm zones. The lower Andaman Sea and upper Gulf of Thailand expect waves around 2 metres, rising above 2 metres during storms. Fishing boats are urged to navigate carefully and avoid thunderstorm areas; small vessels in the upper Andaman should remain ashore during this period. The public is advised to plan activities and travel carefully. Updates are available via the Thai Meteorological Department website at http://www.tmd.go.th or by calling 0-2399-4012-13 and 1182. The next bulletin will be issued on August 18 at 05:00.
Affected provinces by date:
August 18: Extremely heavy rain in Bueng Kan and Nakhon Phanom (Northeast), Trat (East). Heavy rain in Mae Hong Son, Chiang Mai, Chiang Rai, Phayao, Nan, Lampang, Phrae, and Tak (North); Nong Khai, Udon Thani, Sakon Nakhon, Kalasin, Mukdahan, Roi Et, Yasothon, Amnat Charoen, Surin, Si Sa Ket, and Ubon Ratchathani (Northeast); Kanchanaburi and Saraburi (Central); Nakhon Nayok and Chanthaburi (East).
August 19: Extremely heavy rain in Chiang Mai, Chiang Rai, Phayao, Nan, Phrae, and Lampang (North); Nong Khai, Bueng Kan, Nakhon Phanom, Sakon Nakhon, Mukdahan, and Kalasin (Northeast); Trat (East). Heavy rain in Mae Hong Son, Lampoon, Uttaradit, Sukhothai, Tak, Phitsanulok, and Phetchabun (North); Loei, Nong Bua Lamphu, Udon Thani, Khon Kaen, Roi Et, Yasothon, Amnat Charoen, Si Sa Ket, and Ubon Ratchathani (Northeast); Saraburi, Kanchanaburi, and Ratchaburi (Central); Nakhon Nayok, Prachuap Khiri Khan, and Chanthaburi (East).
August 20: Heavy rain forecast for select areas.
