December in Hämeenlinna averages a daily high of -0.7°C with nights around -5.4°C. Expect roughly 16.7 wet days totalling 46.7mm. A hard month to visit for comfort alone.
Across the year, the best time to visit Hämeenlinna is June–August.
Based on HAMEENLINNA KATINEN, FI (1.7km), 1995–2024. 23 years of December data.