July in Lowell averages a daily high of 29.4°C with nights around 16.5°C. Expect roughly 10.4 wet days totalling 110.1mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Lowell is May–June.
Based on LOWELL, MA US (4km), 1995–2024. 28 years of July data.