The Meteorological Department issued Announcement No. 1 warning of heavy to very heavy rain across Thailand, affecting the period from 8 to 13 September 2026.
7 September 2026 GMT+7Meteorological DepartmentAnnouncement on Heavy to Very Heavy Rain in Thailand (Effective 8-13 September 2026), No. 1 (191/2569).
From 8 to 13 September 2026, rainfall will increase across Thailand with heavy rain in many areas and very heavy rain in some, starting first in the northeastern region, followed by other regions in subsequent phases.
Between 8 and 11 September 2026, a monsoon trough will pass over the northern, upper central, and northeastern regions, combined with a moderate-strength southwest monsoon covering the Andaman Sea, Thailand, and the Gulf of Thailand, causing heavy rain in many northern areas and very heavy rain in some.
Then, from 12 to 13 September 2026, a high-pressure system or cold air mass from China will extend over the upper northern and upper northeastern regions, causing the monsoon trough to shift southward through the lower central and eastern regions, entering a strong low-pressure area over the central South China Sea. Meanwhile, the southwest monsoon over the Andaman Sea, southern region, and Gulf of Thailand will intensify, resulting in decreased rain in the north and northeast, but increased heavy to very heavy rain in the central region, including Bangkok metropolitan area, eastern region, and southern region.
Residents across Thailand are advised to be cautious of dangers from heavy to very heavy rainfall and accumulated rain that may cause flash floods and mountain runoff. Those in foothill areas near waterways and lowlands should avoid traveling through flood-prone routes, especially low-lying areas susceptible to short-term flooding.
Additionally, from 11 to 13 September 2026, a low-pressure area near the Philippines is expected to intensify into a tropical cyclone and move into the central South China Sea.
For safety and to minimize potential impacts, people are advised to plan their activities and travel carefully during this period. Please follow updates from the Meteorological Department and access information via their website.http://www.tmd.go.thOr contact 0-2399-4012-13 and 1182, available 24 hours.
Information from the Meteorological Department