December in Derry averages a daily high of 9.1°C with nights around 4.6°C. Expect roughly 23.4 wet days totalling 135.4mm. Demanding conditions — pack for it and plan indoor options.
Across the year, the best time to visit Derry is June–September.
Based on MALIN HEAD, EI (41.6km), 1995–2024. 21 years of December data.