TMD warns of heavy rainfall nationwide, storm Bualoi makes landfall in Vietnam

The Thai Meteorological Department (TMD) on Monday (September 29, 2025) issued a weather warning, forecasting widespread heavy rainfall across much of the country over the next 24 hours, with the most intense conditions expected in the Northeast and East.

Provinces likely to face heavy to hefty rain include Bueng Kan, Sakon Nakhon, Nakhon Phanom, Udon Thani, Khon Kaen, Kalasin, Mukdahan, Chanthaburi and Trat. Bangkok and surrounding provinces are forecast to see thunderstorms.

The department urged residents in upper Thailand to be on alert for flash floods, forest run-off and overflowing rivers, especially in foothill areas, low-lying zones and flood-prone communities. The conditions are being driven by a strong monsoon trough crossing the lower North, upper Central region and Northeast, combined with a rather strong southwest monsoon covering the Andaman Sea, the South and the Gulf of Thailand.

In the upper Andaman Sea and upper Gulf, waves are expected to reach 2–3 metres, rising above 3 metres in thundershower areas. In the lower Andaman, waves will reach around 2 metres, rising above 2 metres in storm zones. Mariners are advised to proceed with caution and avoid sailing in storm areas, while small boats in the upper Andaman and upper Gulf should remain ashore until September 30.

Meanwhile, Typhoon Bualoi has made landfall over Quang Binh province in northern Vietnam, weakening into a severe tropical storm. It is forecast to move across north Laos before further downgrading to a tropical depression and then a low-pressure system.

Weather forecast for Thailand: 6am Monday, September 29 to 6am Tuesday, September 30

Bangkok and vicinity

• Thunderstorms in 60% of the area with isolated heavy rain.
• Low temperature: 24–26 °C; High: 31–33 °C
• Southwesterly winds 10–30 km/h

North

• Thunderstorms in 60% of the area with isolated heavy rain, especially in Chiang Rai, Phayao, Nan, Uttaradit, Phitsanulok and Phetchabun.
• Low: 22–24 °C; High: 31–35 °C
• Variable winds 10–30 km/h

Northeast

• Thunderstorms in 70% of the area with strong winds and heavy to very heavy rain in Nong Khai, Bueng Kan, Sakon Nakhon, Nakhon Phanom, Mukdahan, Yasothon, Amnat Charoen, Si Sa Ket, Ubon Ratchathani, Udon Thani, Nong Bua Lamphu, Khon Kaen, Kalasin, Roi Et and Loei.
• Low: 22–25 °C; High: 29–33 °C
• Variable winds 15–30 km/h

Central region

• Thunderstorms in 60% of the area with isolated heavy rain in Kanchanaburi, Suphan Buri, Phra Nakhon Si Ayutthaya, Ratchaburi and Nakhon Pathom.
• Low: 23–25 °C; High: 32–34 °C
• Southwesterly winds 10–25 km/h

East

• Thunderstorms in 70% of the area with strong winds and heavy to very heavy rain in Nakhon Nayok, Prachin Buri, Rayong, Chanthaburi and Trat.
• Low: 23–25 °C; High: 29–33 °C
• Southwesterly winds 20–40 km/h
• Waves 2–3 metres, rising above 3 metres in thunderstorm areas.

South (east coast)

• Thunderstorms in 70% of the area with isolated heavy rain in Prachuap Khiri Khan, Chumphon, Surat Thani and Nakhon Si Thammarat.
• Low: 23–25 °C; High: 31–34 °C
• From Surat Thani northwards: Southwesterly winds 15–35 km/h; waves 1–2 m, about 2 m in storms.
• From Nakhon Si Thammarat southwards: Southwesterly winds 15–30 km/h; waves around 1 m, 1–2 m in storms.

South (west coast)

• Thunderstorms in 80% of the area with heavy to very heavy rain in Ranong, Phang Nga, Phuket, Krabi, Trang and Satun.
• Low: 24–26 °C; High: 29–32 °C
• From Phuket northwards: Southwesterly winds 20–40 km/h; waves 2–3 m, rising above 3 m in storms.
• From Krabi southwards: Southwesterly winds 20–35 km/h; waves around 2 m, rising above 2 m in storms.