Heavy rain and flash-flood warning issued across parts of Thailand
Thunderstorms are forecast over 70% of the North, with isolated heavy rain in several regions and rain expected across 60% of Bangkok and its vicinity.
- The Thai Meteorological Department has forecast widespread thunderstorms and isolated heavy rain across Thailand, with the northern region expecting 70% coverage.
- A flash flood and forest run-off warning has been issued for the public, especially for those in low-lying areas or near waterways.
- The weather is caused by a monsoon trough and a moderate southwest monsoon, which are also creating moderate waves (1-2 meters) in the Andaman Sea and Gulf of Thailand.
- Mariners are advised to navigate with caution and avoid thundershowers, where waves may exceed 2 meters.
The Thai Meteorological Department (TMD) forecast on Sunday (August 2, 2026) that thunderstorms would cover 70% of the North, with isolated heavy rain, while Bangkok and its vicinity would have thunderstorms across 60% of the area.
Over the next 24 hours, isolated heavy rain is expected in parts of Thailand as a monsoon trough lies across the upper North and upper Laos, while a moderate southwest monsoon prevails over the Andaman Sea, Thailand and the Gulf of Thailand.
People are advised to watch for heavy and accumulated rain that could cause flash floods and forest run-off, particularly on foothill slopes near waterways and in low-lying areas.
Moderate winds and waves are forecast in the Andaman Sea and the Gulf of Thailand.
Waves in the upper Andaman Sea are expected to reach 1–2 metres, while those in the lower Andaman Sea and the Gulf will be about 1 metre.
Waves may exceed 2 metres in thundershowers.
Mariners are advised to navigate with caution and avoid areas affected by thundershowers.
Forecast for Thailand from 6am on Sunday (August 2) to 6am on Monday (August 3)
Bangkok and vicinity
- Thunderstorms are expected across 60% of the area.
- Minimum temperatures will range from 25–27 degrees Celsius.
- Maximum temperatures will range from 33–35 degrees Celsius.
- Southwesterly winds will reach 10–20 km/h.
North
- Thunderstorms are expected across 70% of the region, with isolated heavy rain in Mae Hong Son, Chiang Mai, Chiang Rai, Lampang, Phayao, Nan, Tak, Kamphaeng Phet, Uttaradit and Phitsanulok.
- Minimum temperatures will range from 23–28 degrees Celsius.
- Maximum temperatures will range from 30–36 degrees Celsius.
- Southwesterly winds will reach 10–20 km/h.
Northeast
- Thunderstorms are expected across 60% of the region, with isolated heavy rain in Loei, Nong Khai, Bueng Kan, Nong Bua Lamphu, Udon Thani, Sakon Nakhon, Nakhon Phanom and Mukdahan.
- Minimum temperatures will range from 23–24 degrees Celsius.
- Maximum temperatures will range from 30–35 degrees Celsius.
- Southwesterly winds will reach 10–20 km/h.
Central region
- Thunderstorms are expected across 60% of the region, with isolated heavy rain in Nakhon Sawan, Lop Buri, Saraburi, Kanchanaburi and Ratchaburi.
- Minimum temperatures will range from 23–25 degrees Celsius.
- Maximum temperatures will range from 34–35 degrees Celsius.
- Southwesterly winds will reach 10–20 km/h.
East
- Thunderstorms are expected across 60% of the region, with isolated heavy rain in Nakhon Nayok, Prachin Buri, Chanthaburi and Trat.
- Minimum temperatures will range from 24–26 degrees Celsius.
- Maximum temperatures will range from 31–34 degrees Celsius.
- Southwesterly winds will reach 15–30 km/h.
- Waves will be about 1 metre high, rising above 2 metres in thundershowers.
South (east coast)
- Thunderstorms are expected across 40% of the region, mainly in Prachuap Khiri Khan, Chumphon, Surat Thani, Yala and Narathiwat.
- Minimum temperatures will range from 23–26 degrees Celsius.
- Maximum temperatures will range from 33–36 degrees Celsius.
- Southwesterly winds will reach 15–30 km/h.
- Waves will be about 1 metre high, rising above 2 metres in thundershowers.
South (west coast)
- Thunderstorms are expected across 60% of the region, with isolated heavy rain in Ranong, Phang Nga and Phuket.
- Minimum temperatures will range from 23–26 degrees Celsius.
- Maximum temperatures will range from 32–36 degrees Celsius.
- From Phang Nga northwards, southwesterly winds will reach 15–35 km/h. Waves will be 1–2 metres high, rising above 2 metres in thundershowers.
- From Phuket southwards, southwesterly winds will reach 15–30 km/h. Waves will be about 1 metre high, rising above 2 metres in thundershowers.
