Thailand will enter winter on Thursday as temperatures remain cool and rainfall declines in the upper part of the country.

Phuwiang Prakhammin, director-general of the Meteorological Department, on Monday announced the beginning of winter. He forecast winds blowing from the Northeast and East at low altitudes between 100 metres and 3,500 metres. Rain would decline in upper Thailand while continuing in the South.

He expected winter to last until mid-February, with lower temperatures than usual in Chiang Rai, Nan, Nakhon Phanom and Sakol Nakhon provinces.

This winter the average low temperature nationwide will be 20-21 degrees Celsius, lower than last year's 21.9 degrees Celsius, he said. Frost is likely on mountain peaks in December and January.

Mr Phuwiang said the country's lowest temperature is expected to be 7-8 degrees Celsius in Chiang Rai, Nan, Nakhon Phanom and Sakol Nakhon, while the low in greater Bangkok will be 15-17 degrees Celsius.

On Monday and Tuesday, heavy rain is still likely in upper Thailand. Afterwards the rain will decrease, winds will strengthen and temperatures will drop by 2-3 degrees Celsius, he said.