May in Charleston averages a daily high of 26.3°C with nights around 20.1°C. Expect roughly 6.8 wet days totalling 69.1mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Charleston is March–May.
Based on DOWNTOWN CHARLESTON, SC US (0.8km), 1995–2024. 29 years of May data.