Heavy rain to continue across Thailand under monsoon conditions

The Thai Meteorological Department (TMD) forecast continued rain across Thailand on Wednesday (July 29, 2026), as a monsoon trough lies across the North and Northeast, bringing increased rainfall.

Thunderstorms are expected across 70% of Bangkok and its vicinity, with isolated heavy rain.

Over the next 24 hours, isolated very heavy rain is forecast in the Northeast, East and South, while isolated heavy rain is expected in the North, Central region, Bangkok and its vicinity.

The conditions are being driven by a monsoon trough lying across the upper North and Northeast.

A rather strong southwesterly monsoon is also prevailing over the Andaman Sea, Thailand and the Gulf of Thailand.

The public has been advised to beware of heavy to very heavy rain and accumulated rainfall, which could trigger flash floods and run-off, particularly on foothill slopes near waterways and in low-lying areas.

Winds and waves in the upper Andaman Sea are rather strong, with waves of 2–3 metres and above 3 metres during thunderstorms.

Waves in the lower Andaman Sea and upper Gulf of Thailand are about 2 metres, rising above 2 metres during thunderstorms.

Mariners should proceed with caution and avoid sailing in areas with thunderstorms, while small boats in the upper Andaman Sea should remain ashore for the time being.

Weather forecast for Thailand from 6am on Wednesday (July 29, 2026) to 6am on Thursday (July 30, 2026)

Bangkok and its vicinity

• Thunderstorms are forecast across 70% of the area, with isolated heavy rain.
• Minimum temperatures: 26–27°C.
• Maximum temperatures: 32–34°C.
• Southwesterly winds: 10–25 km/h.

North

• Thunderstorms are forecast across 70% of the region, with isolated heavy rain in Mae Hong Son, Chiang Mai, Chiang Rai, Lampang, Phayao, Nan, Phrae, Uttaradit, Tak, Kamphaeng Phet, Phitsanulok, Phichit and Phetchabun.
• Minimum temperatures: 22–26°C.
• Maximum temperatures: 33–35°C.
• Southwesterly winds: 10–20 km/h.

Northeast

• Thunderstorms are forecast across 80% of the region, with isolated heavy to very heavy rain in Loei, Nong Khai, Bueng Kan, Sakon Nakhon, Nong Bua Lamphu, Udon Thani, Nakhon Phanom, Chaiyaphum, Maha Sarakham, Khon Kaen, Kalasin, Mukdahan, Roi Et, Yasothon, Amnat Charoen, Nakhon Ratchasima, Buri Ram, Surin, Si Sa Ket and Ubon Ratchathani.
• Minimum temperatures: 23–24°C.
• Maximum temperatures: 30–34°C.
• Southwesterly winds: 10–20 km/h.

Central region

• Thunderstorms are forecast across 70% of the region, with isolated heavy rain in Nakhon Sawan, Uthai Thani, Lop Buri, Saraburi, Phra Nakhon Si Ayutthaya and Kanchanaburi.
• Minimum temperatures: 24–26°C.
• Maximum temperatures: 33–35°C.
• Southwesterly winds: 10–25 km/h.

East

• Thunderstorms are forecast across 70% of the region, with isolated heavy to very heavy rain in Nakhon Nayok, Prachin Buri, Sa Kaeo, Chachoengsao, Chon Buri, Rayong, Chanthaburi and Trat.
• Minimum temperatures: 23–27°C.
• Maximum temperatures: 29–33°C.
• Southwesterly winds: 20–35 km/h.
• Waves: About 2 metres, rising above 2 metres during thunderstorms.

South (east coast)

• Thunderstorms are forecast across 60% of the region, with isolated heavy rain in Prachuap Khiri Khan, Chumphon, Surat Thani, Nakhon Si Thammarat and Phatthalung.
• Minimum temperatures: 22–26°C.
• Maximum temperatures: 31–33°C.
• Southwesterly winds: 15–35 km/h.
• Waves: About 1 metre, reaching 1–2 metres offshore and rising above 2 metres during thunderstorms.

South (west coast)

• Thunderstorms are forecast across 70% of the region, with isolated heavy to very heavy rain in Ranong, Phang Nga, Phuket, Krabi and Trang.
• Minimum temperatures: 22–24°C.
• Maximum temperatures: 29–33°C.
• From Phang Nga northwards, southwesterly winds will reach 20–40 km/h, with waves of 2–3 metres, rising above 3 metres during thunderstorms.
• From Phuket southwards, southwesterly winds will reach 20–35 km/h, with waves of about 2 metres, rising above 2 metres during thunderstorms.