Heavy rain and strong winds forecast for Bangkok, North and Northeast on alert

Over the next 24 hours, heavy rainfall is also expected in parts of the North, upper Northeast, western Central Plains and the East. People in these regions are advised to watch out for flash floods and water accumulation.

The wet weather is being driven by a moderate southwesterly monsoon over the Andaman Sea, Thailand and the Gulf, combined with a low-pressure cell over northern Vietnam.

Moderate waves are also expected in both the Andaman Sea and the Gulf of Thailand. In the upper Andaman Sea, waves could reach up to 2 metres, while seas in the lower Andaman and upper Gulf may see waves of 1–2 metres. Thunderstorm zones could see waves exceeding 2 metres. Mariners are urged to proceed with caution and avoid sailing in storm-affected areas.

Forecast from 6am Monday, June 30 to 6am Tuesday, July 1:

Bangkok and the surrounding provinces

• Thunderstorms over 70% of the area
• Temperature: 24–25°C (min), 32–35°C (max)
• Southwesterly winds 10–20 km/h

North

• Thunderstorms in 60% of the area, with isolated heavy rain in Mae Hong Son, Chiang Mai, Chiang Rai, Phayao, Nan, Uttaradit and Tak
• Temperature: 23–24°C (min), 31–34°C (max)
• Southwesterly winds 10–20 km/h

Northeast

• Thunderstorms are expected in 40% of the region, with isolated heavy rain in Loei, Nong Khai, Bueng Kan, Nong Bua Lamphu, Udon Thani, Sakon Nakhon, Nakhon Phanom, Chaiyaphum, Kalasin, and Mukdahan.
• Temperature: 23–25°C (min), 31–34°C (max)
• Southwesterly winds 10–20 km/h

Central

• Thunderstorms in 60% of the area, with isolated heavy showers in Uthai Thani, Saraburi, Kanchanaburi, Ratchaburi, Nakhon Pathom, Samut Songkhram, and Samut Sakhon.
• Temperature: 24–25°C (min), 33–35°C (max)
• Southwesterly winds 10–20 km/h

East

• Thunderstorms are expected in 60% of the region, with heavy rain in some areas, including Nakhon Nayok, Prachin Buri, Sa Kaeo, Chachoengsao, Chon Buri, Rayong, Chanthaburi, and Trat.
• Temperature: 23–27°C (min), 30–33°C (max)
• Southwesterly winds 15–35 km/h
• Offshore wave height: 1–2 metres, exceeding 2 metres during thunderstorms

South (East Coast)

• Scattered thunderstorms cover 30% of the area, mainly in Phetchaburi, Prachuap Khiri Khan, Chumphon, and Surat Thani.
• Temperature: 24–26°C (min), 31–35°C (max)
• Southwesterly winds 15–30 km/h
• Sea waves about 1 metre high, rising to over 2 metres in thunderstorm areas                               

South (West Coast)

• Thunderstorms over 30% of the area, especially in Ranong, Phang Nga, and Phuket.
• From Phuket northwards:

Southwesterly winds 20–35 km/h

Sea waves around 2 metres, higher than 2 metres in thunderstorm zones

• From Krabi southwards:

Southwesterly winds 15–35 km/h

Sea waves 1–2 metres, exceeding 2 metres during thunderstorms