The Meteorological Department issued its first bulletin warning of heavy to very heavy rain in Thailand, advising to monitor vulnerable areas with impacts from 17 to 20 September 2026.
15 September 2026 GMT+7Meteorological DepartmentAnnouncement on heavy to very heavy rainfall over Thailand (effective from 17 to 20 September 2026), Bulletin No. 1 (205/2569).
From 17 to 20 September 2026, Thailand will experience heavy to very heavy rain in some areas, starting with the northern and northeastern regions on 17 September 2026. Subsequently, the central, eastern, and southern regions will be affected on the following day (18 September 2026).
This is due to a high-pressure area or cold air mass from China spreading over upper northern and upper northeastern Thailand, causing a monsoon trough to shift across lower central, eastern, and upper southern regions. Additionally, the southwest monsoon covering the Andaman Sea, Thailand, and the Gulf of Thailand will strengthen.
Residents throughout Thailand are urged to be cautious of heavy to very heavy rainfall and accumulation, which may cause flash floods and forest runoff. Those in foothill areas near waterways and lowlands should avoid traveling through frequently flooded routes, especially low-lying areas prone to short-term flooding.
Waves and winds in the Andaman Sea will be quite strong, with waves 2 to 3 meters high, and over 3 meters in areas with thunderstorms. Fishermen in the Gulf of Thailand and Andaman Sea should navigate carefully and avoid areas with thunderstorms. Small boats in the Andaman Sea should refrain from leaving shore from 17 to 20 September 2026.
For safety and to minimize potential impacts, residents are advised to plan their activities and travel cautiously during this period. Please follow updates from the Meteorological Department and check information on their website.http://www.tmd.go.thOr contact 0-2399-4012-13 and 1182, available 24 hours a day.
17 September 2026
18 September 2026
19 September 2026
20 September 2026