March in Portsmouth averages a daily high of 15.3°C with nights around 4.8°C. Expect roughly 10.3 wet days totalling 97.8mm. 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. 21 years of March data.