Everything still open through September; schedules start thinning only at the very end.
FAQ
Is September a good time to visit Greece?
September is, for many, the single best month in Greece: the sea holds its summer warmth, the crowds drain away after the first week, and prices drop. Summer, minus the stress.
Can you swim in Greece in September?
Sea temperature in September averages 24–25°C. Yes — sea still summer-warm.
How busy is Greece in September?
Crowd levels are medium, falling fast, and prices are mid, falling. Everything still open through September; schedules start thinning only at the very end.