Sunday in Greece starts sunny, but local rain is expected in Western Greece and the Eastern Aegean. Weak winds will persist with temperatures reaching 15°C in Athens. A significant weather change is anticipated on Monday with rain and thunderstorms impacting various regions, along with snowfall in mountainous areas. Tuesday sees continued rain, while temperatures rise slightly before falling to 13°C by Christmas. The cold will be felt nationwide, particularly in northern regions, with ski resorts expecting snow.