December in Keratsíni averages a daily high of 15.5°C with nights around 9.1°C. Expect roughly 8.2 wet days totalling 59.3mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Keratsíni is April–May.
Based on HELLINIKON, GR (13.4km), 1995–2024. 19 years of December data.