TMD warns of flash floods with heavy rain in four regions
Rain will cover up to 60% of several regions, with communities warned of flooding and mariners told to avoid storms producing two-metre waves
The Thai Meteorological Department (TMD) has warned of isolated heavy rain in 24 provinces across four regions on Thursday (September 3, 2026), with accumulated rainfall potentially triggering flash floods and run-off.
The regional forecast, covering 6am on Thursday to 6am on Friday (September 4), names 36 provinces and Bangkok where rain or thunderstorms are expected. Rainfall will cover up to 60% of several regions.
A monsoon trough extending across the upper North and upper Laos into Tropical Storm Saudel over the upper South China Sea is bringing unsettled conditions. A moderate southwest monsoon is also prevailing over the Andaman Sea, Thailand and the Gulf of Thailand.
People living near foothills, waterways and low-lying areas should monitor conditions closely. The TMD advised motorists to avoid routes prone to repeated flooding, particularly low-lying roads where water could accumulate rapidly.
Saudel heads towards southern China
Tropical Storm Saudel is forecast to make landfall in southern China on Thursday night before weakening into a tropical depression. The storm will not enter Thailand.
Travellers heading to the affected part of China should check the weather before departure.
Waves in the upper Andaman Sea will be about two metres high and could exceed two metres during thunderstorms. Mariners in the Andaman Sea and Gulf of Thailand should navigate cautiously and avoid stormy areas.
Regional forecast
North: Thunderstorms are forecast across 60% of the region, with isolated heavy rain in Chiang Rai, Phayao, Nan, Tak, Uttaradit, Phitsanulok and Phetchabun. Temperatures will range from lows of 22–27°C to highs of 31–36°C. Southwesterly winds will reach 10–20 kilometres per hour.
Northeast: Thunderstorms will cover 60% of the region, with isolated heavy rain in Bueng Kan, Nakhon Phanom, Mukdahan, Roi Et, Yasothon, Amnat Charoen, Si Sa Ket and Ubon Ratchathani. Temperatures will range from 23–25°C to 32–35°C, with southwesterly winds of 10–20km/h.
Central region: Thunderstorms are expected across 40% of the region, mainly in Nakhon Sawan, Lop Buri, Saraburi, Kanchanaburi and Ratchaburi. Temperatures will range from 23–26°C to 34–36°C, with southwesterly winds of 10–20km/h.
East: Thunderstorms will affect 60% of the region, with isolated heavy rain in Nakhon Nayok, Prachin Buri, Chanthaburi and Trat. Temperatures will range from 24–26°C to 33–35°C. Southwesterly winds will reach 15–35km/h, while waves will be one to two metres and higher than two metres during thunderstorms.
South, east coast: Thunderstorms are forecast across 40% of the region, mainly in Surat Thani, Nakhon Si Thammarat, Phatthalung, Songkhla, Pattani, Yala and Narathiwat. Temperatures will range from 23–26°C to 33–35°C. Southwesterly winds will reach 15–35km/h. Waves will be about one metre, increasing to one to two metres offshore and above two metres during thunderstorms.
South, west coast: Thunderstorms will cover 60% of the region, with isolated heavy rain in Phang Nga, Phuket, Krabi, Trang and Satun. Temperatures will range from 23–27°C to 31–34°C. From Phuket northwards, southwesterly winds will reach 20–35km/h and waves will be about two metres. From Krabi southwards, winds will reach 15–35km/h and waves will be one to two metres. Storm waves could exceed two metres throughout the area.
Bangkok and surrounding provinces: Thunderstorms are forecast across 60% of the area. Temperatures will range from 25–27°C to 34–35°C, with southwesterly winds of 10–25km/h.
