Monsoon covers Thailand as South, East face rain in 70% of areas
The East, the South's west coast and the Central region face heavy rain, while upper Andaman Sea waves may exceed 3 metres in thunderstorms.
- A strong south-westerly monsoon is causing sustained heavy rain across Thailand.
- The South and East are the most heavily impacted regions, with rainfall forecast over 60% to 70% of these areas.
- Authorities have warned residents about the risk of flash floods and run-off, particularly in low-lying areas.
- The monsoon is also generating high waves of 2-3 meters in the Andaman Sea, prompting a warning for mariners and advising small boats to remain ashore.
The Thai Meteorological Department (TMD) forecast on Sunday (June 7, 2026) that a monsoon would continue to affect Thailand, bringing sustained heavy rain, particularly in the South and the East, where rainfall was expected over up to 70% of some areas.
Bangkok and the surrounding provinces were forecast to see thunderstorms.
In its 24-hour forecast, the department said the East, the South’s west coast and the Central region would see heavy rain in some areas, with very heavy rain in parts of the western side of the North.
The conditions were caused by a rather strong south-westerly monsoon covering the Andaman Sea, Thailand and the Gulf of Thailand, combined with a low-pressure cell over upper Myanmar.
People in the affected areas were urged to prepare for heavy to very heavy rain and accumulated rainfall, which could trigger flash floods and run-off, especially in risk areas near waterways and low-lying areas.
Waves in the upper Andaman Sea were expected to be rather strong, reaching 2-3 metres, and more than 3 metres in areas with thunderstorms.
Mariners in the Andaman Sea and the Gulf of Thailand were advised to navigate with caution and avoid sailing in stormy areas, while small boats in the upper Andaman Sea should remain ashore during this period.
Weather forecast for Thailand from 6am on Sunday (June 7) to 6am on Monday (June 8)
Bangkok and the surrounding provinces
- Thunderstorms are forecast over 40% of the area.
- Minimum temperature: 27-28 degrees Celsius
- Maximum temperature: 33-35 degrees Celsius
- South-westerly winds: 10-25 km/h
North
- Thunderstorms are forecast over 60% of the area, with heavy rain in some areas of Chiang Mai, Chiang Rai, Lampang, Phayao, Nan, Phrae and Tak, and very heavy rain in some parts of Mae Hong Son.
- Minimum temperature: 24-26 degrees Celsius
- Maximum temperature: 30-35 degrees Celsius
- South-westerly winds: 10-20 km/h
Northeast
- Thunderstorms are forecast over 30% of the area, mostly in Loei, Nong Khai, Bueng Kan, Udon Thani, Sakon Nakhon and Nakhon Phanom.
- Minimum temperature: 24-25 degrees Celsius
- Maximum temperature: 34-36 degrees Celsius
- South-westerly winds: 10-25 km/h
Central region
- Thunderstorms are forecast over 40% of the area, with heavy rain in some parts of Kanchanaburi.
- Minimum temperature: 25-27 degrees Celsius
- Maximum temperature: 34-36 degrees Celsius
- South-westerly winds: 10-25 km/h
East
- Thunderstorms are forecast over 60% of the area, with heavy rain in some parts of Chanthaburi and Trat.
- Minimum temperature: 25-27 degrees Celsius
- Maximum temperature: 32-35 degrees Celsius
- South-westerly winds: 20-35 km/h
- The sea is expected to have waves about 2 metres high, rising above 2 metres in areas with thunderstorms.
South, east coast
- Thunderstorms are forecast over 60% of the area, mostly in Surat Thani, Nakhon Si Thammarat, Phatthalung, Songkhla, Yala and Narathiwat.
- Minimum temperature: 23-26 degrees Celsius
- Maximum temperature: 32-35 degrees Celsius
- South-westerly winds: 20-35 km/h
- The sea is expected to have waves 1-2 metres high, about 2 metres offshore, and above 2 metres in areas with thunderstorms.
South, west coast
- Thunderstorms are forecast over 70% of the area, with heavy rain in some parts of Ranong, Phangnga and Phuket.
- Minimum temperature: 24-26 degrees Celsius
- Maximum temperature: 31-34 degrees Celsius
- From Ranong northwards: south-westerly winds of 20-40 km/h; waves 2-3 metres high and above 3 metres in areas with thunderstorms.
- From Phangnga southwards: south-westerly winds of 20-35 km/h; waves about 2 metres high and above 2 metres in areas with thunderstorms.
