I often read posts from people who are worried about the weather during their trip to Greece.
To know the weather forecast when I am in Greece or before leaving, I consult meteo.gr
(available in Greek and English)
Very useful with forecasts for each region or for each island. showing the beaches map, wave heights, UV, forecast for sailors and especially the expected wind which is very useful to know if there will be risks of canceled ferry which is possible from 7 to 8 Beaufort (Bf) and
inevitable above 8 Bf (can also cancel flights)
Some 7-day forecast direct links for:
It's available on the web and smartphone apps.
I do not do commercial promotion, this is the National Observatory of Athens website