December in Saint-Hyacinthe averages a daily high of -0.4°C with nights around -8.2°C. Expect roughly 13.8 wet days totalling 86.4mm. A hard month to visit for comfort alone.
Across the year, the best time to visit Saint-Hyacinthe is May–September.
Based on ST HYACINTHE 2, QC CA (7.8km), 1995–2024. 24 years of December data.