September in Keratsíni averages a daily high of 29°C with nights around 20.1°C. Expect roughly 3.1 wet days totalling 21.4mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Keratsíni is April–May.
Based on HELLINIKON, GR (13.4km), 1995–2024. 19 years of September data.