The Meteorological Department will announce the start of winter early next week, about two weeks later than usual, as cool winds remain weak and temperatures are expected to be warmer than usual throughout the season.
Somkhuan Tonjan, head of the department's central weather forecast sub-division, said rains would continue in the upper parts of the country until Sunday amid weakening cool winds. Easterly and southeasterly winds as well as high humidity would prevail in Greater Bangkok.
Moderately cold winds would blanket upper regions from Monday this week to Monday next week, he said, with cooler temperatures in the Northeast. As cooler winds arrive, rain will affect some areas before gradually declining.
The Meteorological Department was likely to announce the beginning of winter early next week, Mr Somkhuan said.
Winter in Thailand officially arrives when morning temperatures in upper regions are under 23 degrees Celsius.
Apart from the delayed onset, Mr Somkhuan said this winter would be less cold than usual. The lowest average temperature would be 21-22 degrees Celsius, compared with 19.9 degrees Celsius on average.
Last year the average low temperature was 20.8 degrees Celsius, he said.
In the North and the Northeast, the lowest temperatures this winter will be 9-10 degrees Celsius. Meanwhile, it will be 17-18 degrees Celsius in Bangkok and 15-16 degrees Celsius in adjacent provinces.
Temperatures will be lowest from early December to late January.
Cold weather and frost would be frequent on mountaintops and winter would end in late February, Mr Somkhuan said.