Meteorological Bulletin No. 6 states that some areas in Thailand will experience heavy rainfall until 2 September. It warns of flash floods and advises avoiding travel in frequently flooded areas. The Gulf of Thailand is experiencing strong waves, and small boats in the upper Andaman Sea should refrain from setting out to sea.
At 05:00 on 29 August 2026, the Meteorological Department issued Bulletin No. 6 (173/2569) regarding heavy to very heavy rainfall in upper Thailand, effective from 29 August to 2 September 2026. It states that during this period, rainfall will increase with heavy to very heavy rain in some areas, especially in the western parts of the north and central regions, upper northeast and eastern parts of the northeast, and the east. This is due to a monsoon trough moving across the north and upper northeast into a strong low-pressure area near northern Vietnam and the Gulf of Tonkin, combined with a fairly strong southwest monsoon covering the Andaman Sea, Thailand, and the Gulf of Thailand. Residents in these areas are urged to be cautious of heavy to very heavy rain and accumulated rainfall, which may cause flash floods and flash floods from mountain streams, especially in foothill areas near waterways and lowlands. People should avoid traveling through routes prone to repeated flooding, especially low-lying areas where short-term waterlogging may occur.
Regarding sea conditions, the upper Andaman Sea will experience fairly strong winds with waves 2-3 meters high; in areas with thunderstorms, waves may exceed 3 meters. The lower Andaman Sea and upper Gulf of Thailand will have waves about 2 meters high, with waves exceeding 2 meters in thunderstorm areas. Mariners in the Andaman Sea and Gulf of Thailand should navigate with caution and avoid sailing in areas with thunderstorms. Small boats in the upper Andaman Sea are advised to refrain from leaving the shore during this period.
For safety and to minimize potential impacts, the public is advised to carefully plan their activities and travel during this time. Citizens should continue to monitor announcements from the Meteorological Department and can access information at http://www.tmd.go.th or call 0-2399-4012-13 and 1182, available 24 hours.