December in Sydney averages a daily high of 25.9°C with nights around 18.5°C. Expect roughly 9.2 wet days totalling 64.4mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Sydney is July–February.
Based on SYDNEY OBSERVATORY HILL, AS (0.8km), 1995–2024. 25 years of December data.