The Meteorological Department issued its third warning. "Heavy to very heavy rain." In upper Thailand, check the list of provinces affected from 18-21 August 2026.
On 16 August 2026, the websiteof the Meteorological Departmentannounced the third warning regarding heavy to very heavy rain in upper Thailand (affecting 18-21 August 2026).
It states that from 18-21 August 2026, Thailand will experience heavy to very heavy rain in some areas, especially in the north and northeast. This is due to a monsoon trough passing through the north and upper northeast, combined with a fairly strong southwest monsoon covering the Andaman Sea, Thailand, and the Gulf of Thailand. Residents in these areas should be cautious of dangers from heavy and persistent rain, which may cause flash floods and mountain runoff, particularly in foothill areas near watercourses and lowlands. Avoid traveling through frequently flooded routes, especially low-lying areas prone to temporary flooding.
Regarding sea conditions, the upper Andaman Sea will have fairly strong winds from 19-21 August 2026, with waves 2-3 meters high. Areas with thunderstorms may see waves over 3 meters. The lower Andaman Sea and upper Gulf of Thailand will have waves about 2 meters high, with waves over 2 meters where thunderstorms occur. Mariners in the Andaman Sea and Gulf of Thailand should navigate cautiously and avoid sailing in stormy areas. Small boats in the upper Andaman Sea should refrain from departing during this period for safety.
For safety and to reduce potential impacts, the public is advised to plan their activities and travel carefully during this time. Please follow announcements from the Meteorological Department and check information on their website.http://www.tmd.go.thor call 0-2399-4012-13 and 1182, available 24 hours.
18 August 2026
19 August 2026
20 August 2026
21 August 2026
