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).
The first two weeks of June have perfect, sunny and warm 80 degree (27 Â°C) weather, with little clouds or rain. Children are not yet out of school, so places are open and not crowded. Do your best to avoid traveling in August, since Athens, like Paris, belongs to the tourists: Some 60% of all Athenians take their summer holiday between the 1st and 15th of August. Stretches when it's well over 100Â°F (38Â°C) are not uncommon in August, when anyone with health problems such as asthma should be wary of Athens's nefos.