July in Portsmouth averages a daily high of 31.4°C with nights around 21.8°C. Expect roughly 11 wet days totalling 152.5mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Portsmouth is April–May.
Based on NORFOLK SOUTH, VA US (7.3km), 1995–2024. 22 years of July data.