Today’s weather: The Meteorological Department issued Bulletin No. 9 warning of continuous rain in Thailand, with very heavy rainfall in some places until 18 May. Areas at risk may experience flash flooding, while Bangkok and nearby provinces will see rain over 60% of the area.
On 17 May 2026, the Meteorological Department released Bulletin No. 9 (69/2569) regarding heavy to very heavy rainfall over Thailand and strong waves in the Andaman Sea, effective until 18 May 2026. It stated that Thailand will experience continuous rain and heavy to very heavy rain in parts of the North, Central, East, and South regions. Residents in these areas are urged to beware of dangers from heavy rainfall and accumulated rain which may cause flash floods and flash floods, especially in foothill areas near waterways and lowland zones. This is due to the strengthening southwest monsoon covering the Andaman Sea, Thailand, and the Gulf of Thailand. People are also advised to take care of their health amid changing weather conditions.
Waves in the Andaman Sea and Gulf of Thailand are quite strong. In the upper Andaman Sea, from Phuket Province northwards, waves are 2–3 meters high, with waves exceeding 3 meters in areas with thunderstorms. In the lower Andaman Sea, from Krabi Province southwards, and in the upper Gulf of Thailand, waves are about 2 meters high, with waves over 2 meters in stormy areas. Fishermen in these areas should navigate with caution and avoid sailing in stormy conditions. Small boats in the upper Andaman Sea should refrain from going out to sea.
Northern region: thunderstorms over 40% of the area with heavy rain in some parts of Tak, Kamphaeng Phet, Phitsanulok, and Phetchabun provinces. Minimum temperatures 23-26°C, maximum 34-37°C. Southwest winds at 10-20 km/h.
Northeastern region: thunderstorms over 60% of the area with heavy rain in some parts of Loei, Nong Khai, Bueng Kan, Nong Bua Lamphu, Udon Thani, Sakon Nakhon, Nakhon Phanom, Yasothon, Amnat Charoen, Sisaket, and Ubon Ratchathani provinces. Minimum temperatures 24-27°C, maximum 33-36°C. Southwest winds at 10-20 km/h.
Central region: thunderstorms over 60% of the area with heavy rain in some parts of Nakhon Sawan, Uthai Thani, Chai Nat, Kanchanaburi, Ratchaburi, Nakhon Pathom, and Samut Sakhon provinces. Minimum temperatures 24-26°C, maximum 35-38°C. Southwest winds at 10-20 km/h.
Eastern region: thunderstorms over 60% of the area with heavy rain in some parts of Nakhon Nayok, Prachinburi, Chachoengsao, Chonburi, Rayong, Chanthaburi, and Trat provinces. Minimum temperatures 25-29°C, maximum 32-36°C. Southwest winds at 15-35 km/h. Sea waves 1-2 meters high, with waves exceeding 2 meters in areas with thunderstorms.
Southern region (East coast): thunderstorms over 60% of the area with heavy rain in some parts of Phetchaburi, Prachuap Khiri Khan, Chumphon, Surat Thani, and Nakhon Si Thammarat provinces. Minimum temperatures 23-26°C, maximum 34-36°C. Southwest winds at 15-35 km/h. Sea waves about 1 meter high near shore, 1-2 meters offshore, and over 2 meters in areas with thunderstorms.
Southern region (West coast): thunderstorms over 60% of the area with heavy to very heavy rain in some parts of Ranong, Phang Nga, Phuket, Krabi, and Trang provinces. Minimum temperatures 23-26°C, maximum 30-34°C. From Phang Nga northwards: southwest winds at 20-40 km/h, sea waves 2-3 meters high, with waves exceeding 3 meters in stormy areas. From Phuket southwards: southwest winds at 15-35 km/h, sea waves 1-2 meters high, with waves over 2 meters in areas with thunderstorms.
Bangkok and vicinity: thunderstorms over 60% of the area with heavy rain in some places. Minimum temperatures 26-28°C, maximum 35-37°C. Southwest winds at 10-20 km/h.