January in Boston averages a daily high of 3.1°C with nights around -4.5°C. Expect roughly 12 wet days totalling 89mm. A hard month to visit for comfort alone.
Across the year, the best time to visit Boston is May–September.
Based on BOSTON LOGAN INTERNATIONAL AIRPORT, MA US (4.1km), 1995–2024. 30 years of January data.