Heavy rain and flash flood risks persist across southern Thailand
Small boats in the lower Gulf are advised to stay ashore as waves reach 2–3 metres, while accumulated rainfall raises flood risks near foothills and in lowlands.
- The Thai Meteorological Department has issued a warning for heavy to very heavy rain across southern Thailand, effective through November 13.
- There is a significant risk of flash floods and rapid run-off, especially in low-lying areas and on foothill slopes near waterways.
- Mariners are advised to proceed with caution due to strong winds and high waves in the Gulf of Thailand and Andaman Sea, with small boats in the lower Gulf urged to stay ashore.
- Numerous provinces on both the east and west coasts are expected to be affected, including Chumphon, Surat Thani, and Nakhon Si Thammarat.
The Thai Meteorological Department issued a warning on Thursday (November 12, 2026) for isolated heavy to very heavy rain in southern Thailand through November 13.
People should beware of accumulated rainfall that could trigger flash floods and rapid run-off, particularly on foothill slopes near waterways and in low-lying areas.
Fairly strong winds and waves are expected in the lower Gulf of Thailand.
Mariners in the Gulf of Thailand and the Andaman Sea should check their routes, proceed cautiously and avoid areas with thundershowers.
Small boats in the lower Gulf should remain ashore during this period.
Temperatures in upper Thailand are beginning to rise, although mornings will remain cool with light mist.
Rain is also expected in some areas.
People should take care of their health as weather conditions change, while farmers should take precautions to protect their crops from damage.
The fairly strong high-pressure system, or cold air mass, covering upper Thailand and the South China Sea is beginning to weaken.
Meanwhile, a westerly trough is moving over the upper North and northern Laos, while a moderate northeast monsoon prevails over the Gulf of Thailand and the South.
People should plan their daily activities and travel carefully to stay safe and reduce potential impacts. They should continue following the department’s announcements, with information available around the clock at tmd.go.th or by calling 0-2399-4012-13 and 1182.
The warning was issued at 5.00pm, with the next announcement due at 5am on November 13.
Provinces expected to be affected
November 12
Very heavy rain
- South, east coast: Chumphon, Surat Thani and Nakhon Si Thammarat.
Heavy rain
- South, east coast: Prachuap Khiri Khan, Phatthalung, Songkhla, Pattani, Yala and Narathiwat.
- South, west coast: Phang Nga, Phuket, Krabi, Trang and Satun.
November 13
Very heavy rain
- South: Prachuap Khiri Khan, Chumphon and Surat Thani.
Heavy rain
- South: Phetchaburi, Nakhon Si Thammarat, Phatthalung, Songkhla, Pattani, Yala, Narathiwat, Ranong, Phang Nga, Krabi, Trang and Satun.
The forecast covers 6pm on November 12 to 6pm on November 13.
The South’s heavy and very heavy rain areas for this forecast period are those listed under November 12 above.
North
- Cool mornings with light mist. Rain or thundershowers will cover 10% of the region, mainly in Mae Hong Son, Chiang Mai, Chiang Rai, Phayao and Nan.
- Minimum temperatures: 17–24°C.
- Maximum temperatures: 23–31°C.
- Mountaintops will be cold, with minimum temperatures of 10–15°C.
- Northeasterly winds: 10–20 km/h.
Northeast
- Cool mornings with light mist, a temperature rise of 1–2°C and isolated rain.
- Minimum temperatures: 20–23°C.
- Maximum temperatures: 28–32°C.
- Mountaintops will be cool to cold, with minimum temperatures of 11–17°C.
- Northeasterly winds: 10–25 km/h.
Central region
- Cool mornings with light mist and a temperature rise of 1–2°C.
- Minimum temperatures: 21–25°C.
- Maximum temperatures: 30–32°C.
- Easterly winds: 10–20 km/h.
East
- Cool mornings with light mist, a temperature rise of 1–2°C and isolated light rain.
- Minimum temperatures: 22–25°C.
- Maximum temperatures: 32–34°C.
- Northeasterly winds: 15–30 km/h.
- Waves will be about 1 metre high, exceeding 1 metre offshore.
South (east coast)
- Thundershowers covering 70% of the region, with isolated heavy to very heavy rain.
- Minimum temperatures: 21–25°C. Maximum temperatures: 29–35°C.
- From Surat Thani northwards: northeasterly winds of 15–35 km/h, with waves of 1–2 metres, exceeding 2 metres in thundershowers.
- From Nakhon Si Thammarat southwards: easterly winds of 20–40 km/h, with waves of 2–3 metres, exceeding 3 metres in thundershowers.
South (west coast)
- Thundershowers covering 60% of the region, with isolated heavy rain.
- Minimum temperatures: 23–25°C. Maximum temperatures: 29–34°C.
- Easterly winds: 15–35 km/h.
- Waves will be about 1 metre high, rising to 1–2 metres offshore and exceeding 2 metres in thundershowers.
Bangkok and surrounding provinces
- Mostly cloudy, with a temperature rise of 1–2°C and isolated light rain.
- Minimum temperatures: 24–26°C.
- Maximum temperatures: 31–33°C.
- Northeasterly winds: 10–20 km/h.
