December in Windsor averages a daily high of 3.5°C with nights around -2.6°C. Expect roughly 13.5 wet days totalling 66.6mm. A hard month to visit for comfort alone.
Across the year, the best time to visit Windsor is May–June.
Based on WINDSOR RIVERSIDE, ON CA (7.8km), 1995–2024. 29 years of December data.