Bangkok faces heavy rain while monsoon persists over Thailand
Heavy rain is forecast in parts of central, eastern and southern Thailand, with warnings over flash floods, forest run-off and stormy seas.
- Bangkok and its vicinity are forecast to experience heavy rain and thunderstorms across 60% of the area.
- The severe weather is caused by a moderate southwest monsoon that continues to persist over Thailand, the Andaman Sea, and the Gulf of Thailand.
- Authorities have warned residents in affected areas of the risk of flash floods and forest run-off due to the heavy and accumulated rainfall.
- The monsoon is also bringing isolated heavy rain to Thailand's Central, Eastern, and Southern regions.
The Thai Meteorological Department (TMD) forecast weather conditions on Sunday (June 21, 2026), warning people in Bangkok and its vicinity to prepare for heavy rain and thunderstorms across 60% of the area, as the monsoon continues to cover Thailand.
Over the next 24 hours, isolated heavy rain is forecast in the Central region, including Bangkok and its vicinity, the East and the South, as the moderate southwest monsoon continues to cover the Andaman Sea, Thailand and the Gulf of Thailand.
People in these areas are urged to beware of heavy rain and accumulated rainfall, which may cause flash floods and forest run-off, especially in risk areas near waterways and low-lying areas.
Moderate wind and waves are forecast in the upper Andaman Sea, with waves 1-2 metres high.
Waves in the lower Andaman Sea and the Gulf of Thailand are forecast at about 1 metre, rising to more than 2 metres in thunderstorms.
All vessels in the Andaman Sea and the Gulf of Thailand are advised to proceed with caution and avoid sailing in thunderstorm areas.
Weather forecast for Thailand from 6am on Sunday (June 21) to 6am on Monday (June 22)
Bangkok and vicinity
- Thunderstorms are forecast across 60% of the area, with isolated heavy rain.
- Minimum temperature: 25-27°C
- Maximum temperature: 34-36°C
- Southwesterly winds: 10-20 km/h
North
- Thunderstorms are forecast across 40% of the area, mostly in Mae Hong Son, Chiang Mai, Chiang Rai, Lampang, Phayao, Nan, Tak, Kamphaeng Phet and Phetchabun.
- Minimum temperature: 23-26°C
- Maximum temperature: 33-36°C
- Southwesterly winds: 10-20 km/h
Northeast
- Thunderstorms are forecast across 30% of the area, mostly in Loei, Nong Khai, Bueng Kan, Sakon Nakhon, Nakhon Phanom, Chaiyaphum, Nakhon Ratchasima, Buri Ram and Ubon Ratchathani.
- Minimum temperature: 24-26°C
- Maximum temperature: 34-36°C
- Southwesterly winds: 10-20 km/h
Central region
- Thunderstorms are forecast across 60% of the area, with isolated heavy rain in Phra Nakhon Si Ayutthaya, Suphan Buri, Saraburi, Kanchanaburi, Ratchaburi, Nakhon Pathom and Samut Sakhon.
- Minimum temperature: 23-26°C
- Maximum temperature: 35-37°C
- Southwesterly winds: 10-20 km/h
East
- Thunderstorms are forecast across 60% of the area, with isolated heavy rain in Nakhon Nayok, Chon Buri, Rayong, Chanthaburi and Trat.
- Minimum temperature: 23-26°C
- Maximum temperature: 31-36°C
- Southwesterly winds: 15-30 km/h
- Waves are forecast at about 1 metre, rising to more than 2 metres in thunderstorms.
South (east coast)
- Thunderstorms are forecast across 60% of the area, with isolated heavy rain in Surat Thani, Nakhon Si Thammarat, Phatthalung, Songkhla, Pattani, Yala and Narathiwat.
- Minimum temperature: 23-25°C
- Maximum temperature: 33-35°C
- Southwesterly winds: 15-30 km/h
- Waves are forecast at about 1 metre, rising to more than 2 metres in thunderstorms.
South (west coast)
- Thunderstorms are forecast across 60% of the area, with isolated heavy rain in Phangnga, Krabi, Trang and Satun.
- Minimum temperature: 23-26°C
- Maximum temperature: 30-34°C
- From Phuket province northward: southwesterly winds of 15-35 km/h, with waves 1-2 metres high and more than 2 metres in thunderstorms.
- From Krabi province southward: southwesterly winds of 15-30 km/h, with waves about 1 metre high and more than 2 metres in thunderstorms.
