TMD forecasts rain in 80% of central Thailand on Sept 27–28

The Thai Meteorological Department (TMD) warned on Sunday (September 27, 2026) of heavy to very heavy rain in parts of Thailand and waves of 2–3 metres in the upper Gulf of Thailand and upper Andaman Sea. Bangkok and surrounding provinces are forecast to receive less rain, although isolated heavy showers remain possible.

The TMD’s Weather Advisory No.16 (232/2026), effective from 5pm on September 27, was signed by director-general Sugunyanee Yavinchan.

Heavy rain brings flash-flood and landslide risks

Heavy rain and isolated very heavy downpours are likely in the North, western parts of the Central region, the East and the upper South, according to the TMD. The department warned that heavy and accumulated rainfall could trigger flash floods, overflowing waterways and landslides, particularly along waterways near foothills and in low-lying areas.

 

The TMD said a low-pressure cell had moved over Myanmar’s western coast and the Gulf of Martaban. A relatively strong south-west monsoon continued to prevail over the Andaman Sea, southern Thailand and the Gulf of Thailand.

The forecast for less rain in Bangkok and surrounding provinces does not exclude isolated heavy showers, according to the advisory. The capital was also included in earlier heavy-rain warnings. nationthailand

Small boats advised to stay ashore through September 28

Small boats in the upper Gulf of Thailand and upper Andaman Sea should remain ashore through Monday (September 28), the TMD advised.

Strengthening winds are expected to generate waves of 2–3 metres in the upper Gulf and upper Andaman Sea, rising above 3 metres in thunderstorms, according to the TMD.

In the lower Gulf and lower Andaman Sea, the TMD forecasts waves of about 2 metres, exceeding 2 metres in thunderstorms. All vessels should proceed with caution and avoid thunderstorm areas.

The TMD scheduled its next advisory for 11pm on September 27.

Regional weather forecast for September 27–28

The TMD’s regional forecast below covers 6pm on September 27 to 6pm on September 28, 2026. All times are Thailand local time.

North: thunderstorms across 60% of the region

• Thunderstorms are forecast across 60% of the North, with isolated heavy rain in Chiang Mai, Lamphun, Lampang, Phrae, Uttaradit, Sukhothai, Phitsanulok, Phichit and Phetchabun.
• Isolated very heavy rain is expected in Tak and Kamphaeng Phet.
• Minimum temperatures will range from 23–25°C, with maximum temperatures of 30–36°C.
• Easterly winds will reach 10–20 km/h.

Northeast: thunderstorms across 60% of the region

• Thunderstorms are forecast across 60% of the Northeast, with isolated heavy rain in Chaiyaphum, Nakhon Ratchasima and Buri Ram.
• Minimum temperatures will range from 23–24°C, with maximum temperatures of 27–33°C.
• Easterly winds will reach 10–25 km/h.

Central region: thunderstorms across 80% of the region

• Thunderstorms are forecast across 80% of the Central region, with isolated heavy rain in Chai Nat, Lop Buri, Saraburi, Sing Buri, Ang Thong, Ayutthaya, Nakhon Pathom, Samut Sakhon and Samut Songkhram.
• Isolated very heavy rain is expected in Nakhon Sawan, Uthai Thani, Suphan Buri, Kanchanaburi and Ratchaburi.
• Minimum temperatures will range from 22–24°C, with maximum temperatures of 26–31°C.
• Winds will be variable at 10–25 km/h.

East: thunderstorms across 70% of the region

• Thunderstorms are forecast across 70% of the East, with isolated heavy rain in Prachin Buri, Sa Kaeo and Chachoengsao.
• Isolated very heavy rain is expected in Nakhon Nayok, Chonburi, Rayong, Chanthaburi and Trat.
• Minimum temperatures will range from 22–24°C, with maximum temperatures of 26–28°C.
• South-westerly winds will reach 20–40 km/h.
• Waves will reach 2–3 metres, exceeding 3 metres in thunderstorms.