July in Washington averages a daily high of 31.7°C with nights around 22.3°C. Expect roughly 10.5 wet days totalling 117.5mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Washington is April–May.
Based on WASHINGTON REAGAN NATIONAL AIRPORT, VA US (5.3km), 1995–2024. 30 years of July data.