July in Rockville averages a daily high of 32°C with nights around 20.2°C. Expect roughly 9.8 wet days totalling 126.9mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Rockville is April–May.
Based on DALECARLIA RESERVOIR, MD US (16.5km), 1995–2024. 24 years of July data.