Southwest monsoon brings thunderstorms to 32 Thai provinces
The southwest monsoon and a low-pressure cell over upper Vietnam will bring thunderstorms to parts of Thailand, with waves exceeding two metres in stormy areas.
- The Thai Meteorological Department (TMD) has forecast thunderstorms and heavy rain for 32 provinces on Sunday, July 19.
- The weather is caused by a southwest monsoon prevailing over the Andaman Sea and Thailand, along with a low-pressure cell over Vietnam.
- Mariners are advised to proceed with caution due to moderate waves of 1-2 meters, which could exceed 2 meters in areas with thunderstorms.
- The thunderstorms are expected across all regions of the country, with the Northern, Eastern, and Southern regions forecast to have the most coverage.
The Thai Meteorological Department (TMD) warned of heavy rain and thunderstorms in 32 provinces on Sunday (July 19, 2026), as the southwest monsoon continued to prevail over Thailand.
Over the next 24 hours, thunderstorms are expected in some parts of the country as the southwest monsoon continues to cover the Andaman Sea, Thailand and the Gulf of Thailand, while a low-pressure cell covers upper Vietnam.
People are advised to be aware of thunderstorms.
Moderate wind and waves are expected in the upper Andaman Sea and the upper Gulf of Thailand, with waves 1–2 metres high.
Waves in the lower Andaman Sea will be about 1 metre high, rising above 2 metres in thundery areas.
Mariners are advised to proceed with caution and avoid sailing in areas affected by thunderstorms.
Weather forecast for Thailand from 6am on Sunday (July 19) to 6am on Monday (July 20)
Bangkok and vicinity
- Thunderstorms are forecast across 20% of the area.
- Minimum temperature: 25–27°C
- Maximum temperature: 35–37°C
- Southwesterly winds: 10–20 km/h
Northern region
- Thunderstorms are forecast across 30% of the area, mainly in Mae Hong Son, Chiang Mai, Chiang Rai, Phayao, Nan and Tak.
- Minimum temperature: 22–26°C
- Maximum temperature: 27–36°C
- Southwesterly winds: 10–20 km/h
Northeastern region
- Thunderstorms are forecast across 20% of the area, mainly in Loei, Nong Khai, Bueng Kan, Sakon Nakhon, Nakhon Phanom and Ubon Ratchathani.
- Minimum temperature: 23–25°C
- Maximum temperature: 34–37°C
- Southwesterly winds: 10–20 km/h
Central region
- Thunderstorms are forecast across 20% of the area, mainly in Nakhon Sawan, Uthai Thani, Chai Nat, Kanchanaburi, Ratchaburi and Nakhon Pathom.
- Minimum temperature: 23–26°C
- Maximum temperature: 35–37°C
- Southwesterly winds: 10–20 km/h
Eastern region
- Thunderstorms are forecast across 30% of the area, mainly in Nakhon Nayok, Rayong, Chanthaburi and Trat.
- Minimum temperature: 23–26°C
- Maximum temperature: 32–36°C
- Southwesterly winds: 15–35 km/h
- Waves will be 1–2 metres high and more than 2 metres high in thundery areas.
Southern region (east coast)
- Thunderstorms are forecast across 30% of the area, mainly in Nakhon Si Thammarat, Phatthalung, Songkhla, Pattani, Yala and Narathiwat.
- Minimum temperature: 23–26°C
- Maximum temperature: 34–36°C
- Southwesterly winds: 15–30 km/h
- Waves will be about 1 metre high, rising above 1 metre offshore and above 2 metres in thundery areas.
Southern region (west coast)
- Thunderstorms are forecast across 30% of the area, mainly in Phuket, Krabi, Trang and Satun.
- Minimum temperature: 24–26°C
- Maximum temperature: 32–34°C
- From Phang Nga northwards, southwesterly winds will reach 15–35 km/h. Waves will be 1–2 metres high and more than 2 metres high in thundery areas.
- From Phuket southwards, southwesterly winds will reach 15–30 km/h. Waves will be about 1 metre high and more than 2 metres high in thundery areas.
