December in Weymouth averages a daily high of 6.2°C with nights around -2.4°C. Expect roughly 12.7 wet days totalling 127.5mm. A hard month to visit for comfort alone.
Across the year, the best time to visit Weymouth is May–September.
Based on HINGHAM, MA US (2.3km), 1995–2024. 30 years of December data.