Flash flood risks rise with heavy rain across western Thailand
The Thai Meteorological Department has warned of heavy to very heavy rain, flash-flood risks and rough seas, with waves above four metres through July 15.
- Thailand's meteorological department has issued a warning for heavy to very heavy rain across western parts of the country, effective from July 10 to 15.
- The severe weather is caused by a strengthening southwest monsoon, creating a significant risk of flash floods and forest run-off in affected areas.
- Provinces identified as being at high risk include Kanchanaburi in the Central region, Chanthaburi and Trat in the East, and Ranong and Phang Nga in the South.
- In addition to the flood risk, the weather system is generating strong winds and high waves (2-4 meters), prompting a warning for mariners in the Andaman Sea and Gulf of Thailand.
The Thai Meteorological Department (TMD) issued a warning at 5pm on Friday (July 10, 2026) over strong winds and waves in the Andaman Sea and the upper Gulf of Thailand.
It also forecast heavy to very heavy rain on the west coast of the South, the western side of the Central region and the East.
The warning remains in effect through July 15, with provinces at risk listed for July 11 to 14.
Saturday (July 11)
Provinces expected to be affected by very heavy rain:
- Central: Kanchanaburi
- East: Trat
- Provinces expected to be affected by heavy rain:
- East: Chanthaburi
- South: Ranong and Phang Nga
Sunday (July 12)
Provinces expected to be affected by very heavy rain:
- Central: Kanchanaburi and Ratchaburi
- East: Chanthaburi and Trat
- South: Phetchaburi, Prachuap Khiri Khan, Ranong and Phang Nga
- Provinces expected to be affected by heavy rain:
- East: Nakhon Nayok, Prachin Buri and Sa Kaeo
- South: Chumphon, Surat Thani, Phuket and Krabi
Monday (July 13)
Provinces expected to be affected by very heavy rain:
- Central: Kanchanaburi
- East: Chanthaburi and Trat
- South: Prachuap Khiri Khan, Chumphon, Surat Thani, Ranong and Phang Nga
- Provinces expected to be affected by heavy rain:
- Central: Ratchaburi
- East: Nakhon Nayok, Prachin Buri and Sa Kaeo
- South: Phetchaburi, Phuket and Krabi
Tuesday (July 14)
Provinces expected to be affected by very heavy rain:
- Central: Kanchanaburi
- East: Chanthaburi and Trat
- Provinces expected to be affected by heavy rain:
- Central: Ratchaburi
- East: Nakhon Nayok, Prachin Buri and Rayong
- South: Phetchaburi, Prachuap Khiri Khan, Chumphon, Surat Thani, Ranong and Phang Nga
From July 10 to 15, the southwest monsoon prevailing over the Andaman Sea, Thailand and the Gulf of Thailand will strengthen.
Waves in the upper Andaman Sea are forecast to reach 2-4 metres and rise above four metres in thundershowers.
The upper Gulf of Thailand and the lower Andaman Sea will have waves of 2-3 metres, rising above three metres in thundershowers.
Mariners in the Andaman Sea and the Gulf of Thailand are advised to proceed with caution and avoid areas affected by thundershowers, while small boats should remain ashore during the period.
From July 11 to 14, isolated heavy to very heavy rain is forecast on the west coast of the South, the western side of the Central region and the East, particularly in Ranong, Phang Nga, Chanthaburi, Trat and Kanchanaburi.
People in these areas are advised to be aware of heavy to very heavy and accumulated rainfall, which may cause flash floods and forest run-off, particularly on slopes near waterways and in low-lying areas.
Typhoon Bavi over the Pacific Ocean is expected to pass Taiwan and make landfall on the eastern side of Fujian province in China between July 11 and 12.
The typhoon will not enter Thailand and will therefore have no direct impact on the country’s weather, although it will strengthen the southwest monsoon prevailing over Thailand.
Travellers planning to visit the affected areas are advised to check weather conditions before departure.
For safety and to reduce possible impacts, people are advised to plan their daily activities and journeys carefully during the period and follow announcements from the TMD.
Updates are available at http://www.tmd.go.th or by calling 0-2399-4012-13 and 1182, 24 hours a day.
