August in Rockville averages a daily high of 31°C with nights around 19.6°C. Expect roughly 9.5 wet days totalling 114.2mm. 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 August data.