January in Weymouth averages a daily high of 3.4°C with nights around -5.4°C. Expect roughly 13.5 wet days totalling 118mm. 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 January data.