Storm Narra moves towards Guangxi and four Thai regions face heavy rain

The Thai Meteorological Department (TMD) on Sunday (August 23, 2026) forecast thunderstorms across Thailand over the next 24 hours, with isolated heavy rain in the North, the upper Northeast, the Central region and the East.

A monsoon trough extends across the upper North and upper Laos into Tropical Storm Narra over the Gulf of Tonkin, while a rather strong southwest monsoon prevails over the Andaman Sea, Thailand and the Gulf of Thailand.

People in those areas were advised to remain alert to the dangers posed by heavy rain and accumulated rainfall, which could lead to flash floods, rapid run-off from forested areas and rivers overflowing their banks, particularly on foothill slopes near waterways and in low-lying areas.

Winds and waves in the upper Andaman Sea are rather strong, with waves 2–3 metres high and exceeding 3 metres in thunderstorms.

In the upper Gulf of Thailand, waves are about 2 metres high and exceed 2 metres in thunderstorms.

Mariners in the Andaman Sea and Gulf of Thailand were advised to proceed with caution and avoid areas with thunderstorms.

Small boats in the upper Andaman Sea should remain ashore for the time being.

Tropical Storm Narra over the Gulf of Tonkin is likely to make landfall in southern Guangxi, China, between Monday (August 24) and Tuesday (August 25).

It will not move into Thailand and will therefore have no direct effect on the country’s weather.

Travellers planning to visit the area were advised to check weather conditions before setting out during that period.

Thailand weather forecast from 6am on Sunday (August 23) to 6am on Monday (August 24)

North

• Thunderstorms across 60% of the region, with isolated heavy rain.
• Areas with heavy rain: Mae Hong Son, Chiang Mai, Chiang Rai, Phayao, Nan, Uttaradit, Phitsanulok, Phetchabun and Tak.
• Minimum temperature: 22–27°C.
• Maximum temperature: 32–34°C.
• Southwesterly winds: 10–20 km/h.

Northeast

• Thunderstorms across 40% of the region, with isolated heavy rain.
• Areas with heavy rain: Nong Khai, Bueng Kan and Nakhon Phanom.
• Minimum temperature: 23–25°C.
• Maximum temperature: 32–33°C.
• Southwesterly winds: 10–20 km/h.

Central region

• Thunderstorms across 60% of the region, with isolated heavy rain.
• Areas with heavy rain: Nakhon Sawan, Uthai Thani, Kanchanaburi and Ratchaburi.
• Minimum temperature: 23–25°C.
• Maximum temperature: 31–33°C.
• Southwesterly winds: 10–25 km/h.

East

• Thunderstorms across 60% of the region, with isolated heavy rain.
• Areas with heavy rain: Nakhon Nayok, Prachin Buri, Sa Kaeo, Chanthaburi and Trat.
• Minimum temperature: 24–27°C.
• Maximum temperature: 32–33°C.
• Southwesterly winds: 20–35 km/h.
• Waves about 2 metres high and exceeding 2 metres in thunderstorms.

South (east coast)

• Thunderstorms across 30% of the region.
• Rain mainly in Phetchaburi, Prachuap Khiri Khan, Chumphon and Surat Thani.
• Minimum temperature: 23–25°C.
• Maximum temperature: 31–37°C.
• From Surat Thani northwards: southwesterly winds at 20–35 km/h. Waves 1–2 metres high, about 2 metres offshore and exceeding 2 metres in thunderstorms.
• From Nakhon Si Thammarat southwards: southwesterly winds at 15–35 km/h. Waves about 1 metre high, rising to 1–2 metres offshore and exceeding 2 metres in thunderstorms.

South (west coast)

• Thunderstorms across 30% of the region, with isolated heavy rain.
• Area with heavy rain: Ranong.
• Minimum temperature: 23–25°C.
• Maximum temperature: 32–35°C.
• From Phang Nga northwards: southwesterly winds at 20–40 km/h.
• Waves 2–3 metres high and exceeding 3 metres in thunderstorms.
• From Phuket southwards: southwesterly winds at 15–35 km/h.
• Waves 1–2 metres high and exceeding 2 metres in thunderstorms.

Bangkok and vicinity

• Thunderstorms across 70% of the area.
• Minimum temperature: 25–26°C.
• Maximum temperature: 31–32°C.
• Southwesterly winds: 10–25 km/h.