December in Bihać averages a daily high of 5.4°C with nights around -2.3°C. Expect roughly 13.3 wet days totalling 157.7mm. A hard month to visit for comfort alone.
Across the year, the best time to visit Bihać is June–September.
Based on GOSPIC, HR (49.7km), 1995–2024. 29 years of December data.