"Meteorological Department" (Meteorological Department) Issued the 4th announcement warning that from 29 August to 2 September 2026, several provinces will experience "heavy to very heavy rain" with possible flash floods and forest runoff.
28 August 2026 GMT+7Meteorological DepartmentAnnouncement regarding Heavy to very heavy rain over upper Thailand (effective from 29 August to 2 September 2026), Announcement No. 4 (171/2569) It stated that from 29 August to 2 September 2026, rainfall in Thailand will increase, with some areas experiencing heavy to very heavy rain.
Particularly in the upper northern region, upper northeastern region, and eastern areas, as well as the windward side of the southwest monsoon. This is due to a monsoon trough moving down across the north and upper northeast into a strong low-pressure area over northern Vietnam’s coast and the Gulf of Tonkin, combined with a fairly strong southwest monsoon blowing over the Andaman Sea, Thailand, and the Gulf of Thailand.
Residents in these areas are advised to be cautious of hazards from heavy to very heavy rain and accumulated rainfall, which may cause flash floods and forest runoff, especially in foothill areas near waterways and lowlands. Avoid traveling through flood-prone routes, particularly lowland areas that may experience short-term flooding.
Waves and winds in the upper Andaman Sea will be quite strong, 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 higher than 2 meters in thunderstorm areas. Mariners in the Andaman Sea and Gulf of Thailand should navigate cautiously and avoid sailing where thunderstorms occur. Small boats in the upper Andaman Sea should refrain from leaving shore during these days.
For safety and to reduce possible impacts, residents should carefully plan their activities and travel during this period. Please follow updates from the Meteorological Department, which can be accessed at http://www.tmd.go.th or by calling 0-2399-4012-13 and 1182, available 24 hours.