Widespread thundershowers and heavy rains forecast for most parts of the country

A monsoon trough prevails across the lower Central and East of Thailand, and a strong southwest monsoon prevails over the Andaman Sea, Thailand and the Gulf of Thailand, the department said.

"People should beware of the severe conditions that may cause overflows and flash floods," the department said.

Wind waves 2-4 metres high are expected in the upper Andaman Sea from Phuket northward and above three metres high during thundershowers. In the upper Gulf, waves about two metres high and above two metres during thundershowers are expected.

"All ships in the Andaman Sea and the upper Gulf should proceed with caution, while small boats in the upper Andaman Sea should keep ashore until July 12," the department added.

The 24-hour weather forecast for different regions:

North: Fairly widespread thundershowers with isolated heavy rains in Mae Hong Son, Chiang Mai, Tak, Sukhothai, Phitsanulok, Kamphaeng Phet, Phichit and Phetchabun provinces; minimum temperature 23-25 degrees Celsius, maximum 32-34°C; southeasterly winds 10-25 km/hr.

Northeast: Scattered thundershowers with isolated heavy rains in Chaiyaphum, Khon Kaen, Nakhon Ratchasima, Buri Ram and Surin provinces; minimum temperature 24-25°C, maximum 32-34°C; southeasterly winds 10-25 km/hr.

Central: Fairly widespread thundershowers with isolated heavy rains in Nakhon Sawan, Uthai Thani, Chainat, Sing Buri, Lop Buri, Ang Thong, Saraburi, Ayutthaya, Suphanburi, Kanchanaburi, Ratchaburi, Nakhon Pathom, Samut Songkhram and Samut Sakhon provinces; minimum temperature 24-25°C, maximum 32-34°C; southeasterly winds 10-25 km/hr.

East: Fairly widespread thundershowers with isolated heavy to very heavy rains in Nakhon Nayok, Prachin Buri, Sa Kaew, Chachoengsao, Chonburi, Rayong, Chanthaburi and Trat provinces; minimum temperature 23-25°C, maximum 28-33°C; southeasterly winds 20-35 km/hr; waves about two metres high and above two metres during thundershowers.

South (east coast): Fairly widespread thundershowers with isolated heavy rains mostly in Prachuap Khiri Khan, Chumphon, Surat Thani, Nakhon Si Thammarat and Phatthalung provinces; minimum temperature 23-25°C, maximum 30-33°C.

Chumphon northward: Southwesterly winds 15-35 km/hr; waves 1-2 metres high and above two metres during thundershowers.

Surat Thani southward: Southwesterly winds 15-30 km/hr; waves about a metre high and 1-2 metres during thundershowers.

South (west coast): Fairly widespread thundershowers with isolated heavy to very heavy rains in Ranong, Phang Nga, Phuket, Krabi and Trang provinces; minimum temperature 19-25°C, maximum 27-31°C.

Phuket northward: Southwesterly winds 20-45 km/hr; waves 2-4 metres high and above three metres in thundershowers.

Krabi southward: Southwesterly winds 15-35 km/hr; waves 1-2 metres high and about two metres during thundershowers.

Bangkok and surrounding areas: Fairly widespread thundershowers with isolated heavy rain; minimum temperature 25-26°C, maximum 32-34°C; southeasterly winds 10-25 km/hr.