April in Rockville averages a daily high of 20.4°C with nights around 6.7°C. Expect roughly 10.6 wet days totalling 87mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Rockville is April–May.
Based on DALECARLIA RESERVOIR, MD US (16.5km), 1995–2024. 27 years of April data.