Additionally, on December 20-21, another strong high-pressure system will lead to a temperature drop of 2-4 degrees Celsius in the same areas. Residents are advised to stay healthy due to the fluctuating weather.

In the South, the ongoing moderate northeast monsoon is expected to cause isolated heavy rains until Thursday. Sea conditions in the Gulf and Andaman Sea may see waves up to 2 meters high, or higher during thundershowers. The lower Gulf might experience even rougher seas, with 2-3 meter waves and over 3 meters during storms.

Mariners are urged to exercise caution and avoid thundershower areas, while people in the lower South are warned of possible storm surges midweek.