Greece has a Mediterranean climate with plenty of sunshine, mild temperatures
and a limited amount of rainfall. Due to the country's geographical position,
its rugged relief and its distribution between the mainland and the sea,
there is great variation in Greece's climate. In summer, the dry hot days are
cooled by seasonal winds called the meltemi, while mountainous regions
have generally lower temperatures. The winters are mild in lowland areas,
with a minimum amount of snow and ice, yet, mountains are
usually snow-covered. Moreover, a common phenomenon is the
occurrence of different climactic conditions during the same season
(for instance, mild heat in coastal areas and cool temperatures
in mountainous regions).

Please use this link below for live Athens Forecast

Also, use this link to a pdf file containing Athens' main meteorological data.