Phuket warned of waves above 3 metres during monsoon advisory

The Thai Meteorological Department (TMD) has warned of rough seas along Phuket’s west coast, with waves forecast to reach 2–3 metres and rise above 3 metres in thunderstorms from August 29 to September 2, 2026.

The warning forms part of TMD Weather Advisory No. 3, issued at 5pm on August 27. The department said a strong southwest monsoon would prevail over the Andaman Sea, Thailand and the Gulf of Thailand during the period.

For the southern west coast, thunderstorms are forecast across 30% of the region, with isolated heavy rain in Ranong and Phang Nga. From Phuket northwards, southwesterly winds are expected to reach 20–40km/h, with waves of 2–3 metres and higher than 3 metres during thunderstorms.

The TMD advised all vessels in the Andaman Sea and Gulf of Thailand to proceed with caution and avoid areas affected by thunderstorms. Small boats in the upper Andaman Sea should remain ashore during the warning period.

The wider weather system is also expected to bring heavy to very heavy rain to parts of upper Thailand from August 29 to September 2, increasing the risk of flash floods, overflowing waterways and landslides. The TMD said accumulated rainfall could make slopes unstable, particularly near foothills, waterways and low-lying areas.

The next advisory was scheduled for 5am on August 28.