The Meteorological Department issues Alert No. 13 warning of heavy to very heavy rain, listing provinces at risk of flash floods and mountain runoff, with impacts expected through 21 May 2026.
Date: 19 May 2026 GMT+7 Meteorological Department Announcement regarding heavy to very heavy rain over Thailand and strong waves in the Andaman Sea, Alert No. 13 (effective through 21 May 2026).
It states that during 19–21 May 2026, rainfall will increase with heavy to very heavy rain in some areas, mainly in the western parts of the country including the North, upper Northeast, Central, East, and western South. This is due to a fairly strong southwest monsoon covering the Andaman Sea, Thailand, and the Gulf of Thailand, combined with a low-pressure trough over northern coastal Vietnam.
People in these areas are advised to beware of dangers from heavy to very heavy rainfall and accumulated rain, which may cause flash floods and mountain runoff, especially in foothill areas near waterways and low-lying zones.
Waves and winds in the Andaman Sea and Gulf of Thailand are quite strong, particularly in the upper Andaman Sea from Phuket northward.
Wave heights range from 2 to 3 meters, with waves exceeding 3 meters in thunderstorm areas. In the lower Andaman Sea from Krabi southward and the upper Gulf of Thailand, wave heights are about 2 meters, exceeding 2 meters where thunderstorms occur.
Boaters in these areas should navigate with caution and avoid sailing in regions experiencing thunderstorms. Small boats in the upper Andaman Sea should refrain from going out to sea during this period.
The public is urged to follow announcements from the Meteorological Department and can access information on their website.http://www.tmd.go.thOr call 0-2399-4012-13 and 1182, available 24 hours a day.
Announcement issued on 19 May 2026 at 05:00 GMT+7.
The Meteorological Department will issue the next update on 19 May 2026 at 17:00 GMT+7.
19 May 2026
20 May 2026
21 May 2026
Source: Meteorological Department