It added that the southwest monsoon prevailing over the Andaman Sea and the Gulf will also bring heavy rain to the Northeast and South over the next seven days.
Meanwhile, winds in the Andaman Sea are weakening. Boats have been advised to proceed with caution as waves of around 2 metres will rise higher during thundershowers.
Meanwhile, waves in the upper Gulf are currently about 1-2 metres high but will rise during thundershowers.
The department advised all boats to proceed with caution and avoid thunderstorms.