16 August 2026
Thailand’s Meteorological Department has warned of heavy to very heavy rainfall from August 18 to 21, with the North and Northeast expected to face some of the highest risks.
The department said a monsoon trough is expected to stretch across northern Thailand and the upper Northeast while a relatively strong southwest monsoon covers the Andaman Sea, Thailand and the Gulf of Thailand. The combination could trigger heavy accumulated rainfall in vulnerable areas.
Authorities are warning of possible flash floods and runoff, particularly near foothills, waterways and low-lying areas. Thailand’s northern-region outlook also forecasts thunderstorms across 60% to 80% of the region during August 15 to 21, with very heavy rain possible in some areas between August 18 and 20.
For international visitors and foreign residents, the warning is particularly relevant to overland travel in northern Thailand. Conditions may vary sharply by province, so travelers should follow local warnings rather than treating the forecast as applying equally to every destination.
Vihok News Sources: Thai Meteorological Department