June in Rockville averages a daily high of 29.4°C with nights around 17.6°C. Expect roughly 9.9 wet days totalling 108.7mm. 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. 26 years of June data.