Water condensation during winter

Hi all,

Now we are into winter we have noticed water condensation buildup on the window glass inside the apartment.

After a cold night, water builds up on the glass and when it gets warmer during the day it melts and builds up down at the bottom of the window.

Pictures attached. First thought water was getting in but seems to be melted condensation. Windows are always closed.

Didn't notice this during summer.

Any ideas of what can be done about this?

Thanks