TMD issues heavy rain warning for 29 provinces across Thailand

The Thai Meteorological Department (TMD) has warned of heavy rain in 29 provinces on Monday (July 13, 2026), as the southwest monsoon prevails over the Andaman Sea and a low-pressure cell covers upper Vietnam.

Over the next 24 hours, heavy rain is forecast in some parts of Thailand, with very heavy rain in parts of the upper Northeast, the western part of the Central region, the East and the western coast of southern Thailand.

The strong southwest monsoon is prevailing over the Andaman Sea, Thailand and the Gulf of Thailand, while a low-pressure cell covers upper Vietnam.

People in these areas should beware of hazards from heavy to very heavy rain and accumulated rainfall, which could cause flash floods and forest run-off, particularly on foothill slopes near waterways and in low-lying areas.

Strong winds and waves are expected in the Andaman Sea and the Gulf of Thailand.

Waves in the upper Andaman Sea will be 2-4 metres high, rising above 4 metres during thundershowers.

In the lower Andaman Sea and the upper Gulf, waves will be 2-3 metres high, rising above 3 metres during thundershowers.

Mariners should proceed with caution and avoid sailing in areas of thundershowers.

Small boats in the Andaman Sea and the upper Gulf should remain ashore until Wednesday (July 15, 2026).

People along the west coast of southern Thailand should also beware of waves surging ashore.

Meanwhile, Tropical Storm “Bavi” is over Anhui province, China, and is expected to weaken into a tropical depression and then an active low-pressure cell.

The storm is not expected to enter Thailand.

Travellers to the area should check the weather before departure.

Weather forecast for Thailand from 6am on Monday (July 13) to 6am on Tuesday (July 14)

Bangkok and the surrounding provinces

• Rain or thundershowers are expected across 60% of the area.
• Minimum temperature: 25-27°C
• Maximum temperature: 34-35°C
• Southwesterly winds: 10-30 km/h

North

• Thundershowers are expected across 70% of the area, with heavy rain in some parts of Mae Hong Son, Chiang Mai, Chiang Rai, Phayao, Nan and Tak.
• Minimum temperature: 22-25°C
• Maximum temperature: 30-34°C
• Southwesterly winds: 10-20 km/h

Northeast

• Thundershowers are expected across 70% of the area, with heavy to very heavy rain in some parts of Nong Khai, Bueng Kan, Udon Thani, Sakon Nakhon, Nakhon Phanom, Mukdahan, Amnat Charoen and Ubon Ratchathani.
• Minimum temperature: 22-24°C
• Maximum temperature: 28-35°C
• Southwesterly winds: 10-20 km/h

Central region

• Thundershowers are expected across 40% of the area, with heavy to very heavy rain in some parts of Kanchanaburi and Ratchaburi.
• Minimum temperature: 23-25°C
• Maximum temperature: 31-36°C
• Southwesterly winds: 10-25 km/h

East

• Thundershowers are expected across 60% of the area, with heavy to very heavy rain in some parts of Nakhon Nayok, Prachin Buri, Sa Kaeo, Chanthaburi and Trat.
• Minimum temperature: 24-27°C
• Maximum temperature: 29-35°C
• Southwesterly winds: 20-40 km/h
• Sea waves: 2-3 metres, rising above 3 metres during thundershowers

Southern (east coast)

• Thundershowers are expected across 40% of the area, with heavy rain in some parts of Phetchaburi, Prachuap Khiri Khan, Chumphon and Surat Thani.
• Minimum temperature: 22-25°C
• Maximum temperature: 30-34°C
• From Surat Thani northwards: southwesterly winds at 20-40 km/h. Waves will be 1-2 metres high, rising above 2 metres offshore and during thundershowers.
• From Nakhon Si Thammarat southwards: southwesterly winds at 20-35 km/h. Waves will be 1-2 metres high, about 2 metres offshore and above 2 metres during thundershowers.

Southern (west coast)

• Thundershowers are expected across 70% of the area, with heavy to very heavy rain in some parts of Ranong, Phang Nga, Phuket and Krabi.
• Minimum temperature: 24-27°C
• Maximum temperature: 30-33°C
• From Phuket northwards: southwesterly winds at 20-45 km/h. Waves will be 2-4 metres high, rising above 4 metres during thundershowers.
• From Krabi southwards: southwesterly winds at 20-40 km/h. Waves will be 2-3 metres high, rising above 3 metres during thundershowers.