December in Lillestrøm averages a daily high of 0.8°C with nights around -4.9°C. Expect roughly 11.8 wet days totalling 68.9mm. A hard month to visit for comfort alone.
Across the year, the best time to visit Lillestrøm is June–August.
Based on SKEDSMO HELLERUD, NO (4.6km), 1995–2024. 12 years of December data.