
In the daily weather forecast issued at 6am on Saturday, the department said another strong high pressure area from China will extend to upper Thailand during the period, resulting in a drop in temperature by 2-4C.
The department said the upper part of Thailand would be covered with fog in the morning so motorists need to be careful.
The department added that a moderate northeast monsoon across the Gulf of Thailand would bring isolated heavy rains over the lower part of the country and would cause waves about 2 to 4 metres high in the Gulf from Sunday till January 2.
For the next 24 hours, the department predicted the lowest temperature on northern mountaintops at 8C and northeastern mountaintops at 9C .
The department expected the lowest temperature in Bangkok during the next 24 hours to be around 23 to 25C.