June in Downtown DC averages a daily high of 29.6°C with nights around 18.5°C. Expect roughly 11 wet days totalling 121.2mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Downtown DC is April–May.
Based on NATIONAL ARBORETUM DC, MD US (4.8km), 1995–2024. 27 years of June data.