Generally the liquid is water and the fluid above the liquid is air. The molecules within the liquid attract each other and at the interface there are more attractive forces towards the bulk of the liquid than there are towards the adjacent gas molecules. The molecular forces tend to pull into the fluid bulk.
Weather lowdown. Despite the fact that the month of September in Athens can produce summer-like temperatures, the weather starts to cool off significantly in October, and especially at night. The average temperature this month is 19Â°C (66Â°F), while the average low is 15Â°C (59Â°C), and the average high is 23Â°C (73Â°F).
Climate in Greece in September. The weather in Greece in September is warm and mild. Greeceâs Mediterranean climate means that September weather is still relatively warm. Average temperatures in Athens for September range from 19 to 29Â°C (66 to 84Â°F). The average temperature during September on many of Greeceâs islands is only slightly cooler than that of Athens. Sunshine hours begin to decrease in Greece during September.