December in Lowell averages a daily high of 4.6°C with nights around -5.2°C. Expect roughly 10.8 wet days totalling 114.6mm. A hard month to visit for comfort alone.
Across the year, the best time to visit Lowell is May–June.
Based on LOWELL, MA US (4km), 1995–2024. 29 years of December data.