The Meteorological Department (TMD) issued its 16th bulletin warning that Thailand will continue to experience ongoing rainfall with heavy showers in some areas. It lists provinces expected to be affected, with potential flash floods and mountain torrents.
20 May 2026 GMT+7The Meteorological Department's websiteannounced the following: "Heavy to very heavy rainfall over Thailand and strong winds over the Andaman Sea" in its 16th bulletin (effective through 21 May 2026), stating that during 20–21 May 2026, Thailand will continue to see persistent rainfall with heavy showers in some areas. Particularly heavy rain is expected in parts of the North, upper Northeast, and the western coast of the South. This is due to a fairly strong southwest monsoon covering the upper Andaman Sea and Thailand, combined with a low-pressure trough over the lower North and upper Northeast regions.
Residents in these areas are urged to be cautious of heavy to very heavy rainfall and accumulated rain, which may cause flash floods and mountain torrents, especially in foothill areas near waterways and low-lying areas.
Waves and winds in the Andaman Sea and Gulf of Thailand are fairly strong. In the upper Andaman Sea, from Phuket province northwards, waves reach 2–3 meters high, with waves exceeding 3 meters in areas experiencing thunderstorms. In the lower Andaman Sea, from Krabi province southwards, and in the upper Gulf of Thailand, waves reach about 2 meters high, rising above 2 meters during thunderstorms. Fishermen in these areas are advised to navigate with caution and avoid sailing in stormy conditions. Small boats in the upper Andaman Sea should refrain from leaving shore during these days.
The public is advised to follow updates from the Meteorological Department. Information is available 24 hours a day on the TMD website http://www.tmd.go.th or by calling 0-2399-4012-13 and 1182.
20 May 2026 GMT+7
21 May 2026 GMT+7
Source: Meteorological Department website