TMD warns of heavy rain and flash floods through September 2

SATURDAY, AUGUST 29, 2026
TMD warns of heavy rain and flash floods through September 2

Heavy to very heavy rain is forecast across upper Thailand from August 29 to September 2, raising the risk of flash floods and run-off.

The Thai Meteorological Department (TMD) has warned of heavy to very heavy rain across upper Thailand from Saturday (August 29) to Wednesday (September 2), with residents in vulnerable areas urged to prepare for flash floods and run-off.

The department issued Warning No. 7 at 5pm on Saturday, forecasting increased rainfall across the country during the period.

Heavy to very heavy rain is expected in some areas, particularly in the western parts of the North and Central region, the upper and eastern parts of the Northeast, and the East.

The conditions will be caused by a monsoon trough moving down across the North and upper Northeast towards an active low-pressure cell over the coast of upper Vietnam and the Gulf of Tonkin.

A rather strong southwest monsoon is also prevailing over the Andaman Sea, Thailand and the Gulf of Thailand.

Residents in affected areas have been advised to remain alert for heavy and accumulated rainfall, which could trigger flash floods and run-off, particularly on foothills near waterways and in low-lying areas.

Travellers should avoid routes with recurring flood problems, especially in low-lying locations where temporary flooding may occur.

TMD warns of heavy rain and flash floods through September 2


Strong waves forecast in Andaman Sea

Winds and waves in the upper Andaman Sea will be rather strong, with waves reaching two to three metres and exceeding three metres during thunderstorms.

Waves in the lower Andaman Sea and upper Gulf of Thailand will be about two metres high, rising above two metres in stormy areas.

Mariners in the Andaman Sea and Gulf of Thailand should proceed with caution and avoid sailing in areas affected by thunderstorms.

Small boats in the upper Andaman Sea should remain ashore throughout the warning period.

The TMD urged the public to plan daily activities and journeys carefully to minimise possible risks and disruption.

People can follow further announcements through the TMD website or obtain information around the clock by calling 0 2399 4012-13 or 1182.