TMD issues heavy rain warning No. 12 through October 13
Bangkok is among areas at risk of heavy rain on October 13, with warnings of flash floods, landslides and rough seas in thundershowers.
- The Thai Meteorological Department (TMD) has issued heavy rain warning No. 12, which is in effect through October 13.
- The warning initially covers 12 southern provinces on October 12 before expanding to include Bangkok and other regions in the North, Northeast, Central, and East on October 13.
- The TMD warns of potential flash floods, landslides, and gusty winds, with waves possibly exceeding two meters in the Andaman Sea and Gulf of Thailand during thundershowers.
The Thai Meteorological Department (TMD) issued advisory No. 12 (258/2026) at 5pm Thai time on October 12, 2026, warning of isolated heavy to very heavy rain through October 13. The warning identifies 12 southern provinces at risk on October 12, with Bangkok and other regions covered on October 13.
Thundershowers, gusty winds and lightning are also possible during the October 12–13 warning period, according to the TMD.
Heavy rain risk extends to Bangkok on October 13
Bangkok and its vicinity are included in the TMD’s warning for October 13, alongside the lower North, lower Northeast, Central Region, East and South. The October 12 heavy rain warning focuses on southern Thailand.
Southern provinces at risk on October 12: Prachuap Khiri Khan, Chumphon, Surat Thani, Nakhon Si Thammarat, Phatthalung, Songkhla, Pattani, Yala, Narathiwat, Krabi, Trang and Satun.
The provincial breakdown for heavy rain on October 13 is:
- North: Kamphaeng Phet.
- Northeast: Nakhon Ratchasima, Buri Ram and Surin.
- Central Region: Nakhon Sawan, Uthai Thani, Chai Nat, Sing Buri, Ang Thong, Phra Nakhon Si Ayutthaya, Suphan Buri, Kanchanaburi, Ratchaburi, Nakhon Pathom, Samut Sakhon and Samut Songkhram, together with Bangkok and its vicinity.
- East: Nakhon Nayok, Prachin Buri, Sa Kaeo, Chon Buri, Rayong, Chanthaburi and Trat.
- South: Phetchaburi, Prachuap Khiri Khan, Surat Thani, Yala, Narathiwat, Phang Nga, Phuket and Krabi.
TMD warns of flash floods and waves above two metres
Heavy rain and accumulated rainfall could trigger flash floods, rapid runoff from hills, overflowing waterways and landslides, particularly near foothills, along watercourses and in low-lying areas, the TMD warned. Waves in the Andaman Sea and Gulf of Thailand could exceed two metres in thundershowers.
The TMD advised residents to remain alert to gusty winds and lightning and avoid open areas, sheltering beneath large trees or standing near unstable billboards during thundershowers.
Mariners in the Andaman Sea and Gulf of Thailand should proceed with caution and avoid sailing through thundershowers, the TMD advised.
Chinese high pressure and monsoon conditions drive unsettled weather
The TMD linked the late-rainy-season conditions to a high-pressure system, or cool air mass, from China extending over upper Thailand and the South China Sea, alongside the continuing southwest monsoon over the Andaman Sea.
Easterly and southeasterly winds are carrying moisture from the South China Sea into the lower Northeast, Central Region, East and South, according to the TMD. The department’s English advisory No. 12 places the monsoon trough across the upper South.
Southern regions forecast to have 70% thundershower coverage
The TMD’s separate 24-hour forecast, valid from 6pm on October 12 to 6pm on October 13, predicts thundershowers across 70% of each southern coastal region, with isolated heavy rain.
North: Thundershowers are forecast across 20% of the region, mainly in Mae Hong Son, Chiang Mai, Tak and Kamphaeng Phet. Minimum temperatures are expected at 22–26°C and maximum temperatures at 33–35°C, with easterly winds of 10–20km/h.
Northeast: Thundershowers are forecast across 30% of the region, mainly in Nakhon Ratchasima, Buri Ram, Surin, Si Sa Ket and Ubon Ratchathani. Minimum temperatures are expected at 22–25°C and maximum temperatures at 33–35°C, with northeasterly winds of 10–25km/h.
Central Region: Thundershowers are forecast across 20% of the region, mainly in Kanchanaburi, Ratchaburi, Nakhon Pathom, Samut Sakhon and Samut Songkhram. Minimum temperatures are expected at 23–27°C and maximum temperatures at 33–36°C, with northeasterly winds of 10–20km/h.
East: Thundershowers are forecast across 30% of the region, mainly in Chon Buri, Rayong, Chanthaburi and Trat. Minimum temperatures are expected at 23–27°C and maximum temperatures at 32–35°C, with northeasterly winds of 10–30km/h. Waves are forecast below one metre, rising above two metres in thundershowers.
South, east coast: Thundershowers are forecast across 70% of the region, with isolated heavy rain in Prachuap Khiri Khan, Chumphon, Surat Thani, Nakhon Si Thammarat, Phatthalung, Songkhla, Yala, Narathiwat and Pattani. Minimum temperatures are expected at 22–25°C and maximum temperatures at 32–34°C, with variable winds of 15–30km/h. Waves are forecast at about one metre, rising above two metres in thundershowers.
South, west coast: Thundershowers are forecast across 70% of the region, with isolated heavy rain in Krabi, Trang and Satun. Minimum temperatures are expected at 24–26°C and maximum temperatures at 32–34°C, with variable winds of 15–30km/h. Waves are forecast at about one metre, rising above two metres in thundershowers.
Bangkok and its vicinity: Thundershowers are forecast across 30% of the area. Minimum temperatures are expected at 27–28°C and maximum temperatures at 33–35°C, with northeasterly winds of 10–20km/h.
The TMD urged residents to plan daily activities and travel carefully during the warning period and follow its announcements. Weather information is available through the department’s website and its 24-hour telephone services on 1182, 02-399-4012 and 02-399-4013.
TMD Deputy Director-General Nattawut Dandee, serving as acting director-general, signed advisory No. 12. The department is due to issue its next advisory at 5am on October 13.
