July in Downtown DC averages a daily high of 32.1°C with nights around 21.1°C. Expect roughly 10.6 wet days totalling 117.6mm. 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. 29 years of July data.