May in Harrisburg averages a daily high of 22.4°C with nights around 10.8°C. Expect roughly 13.1 wet days totalling 115.6mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Harrisburg is May–June.
Based on HARRISBURG 1 NE, PA US (1.5km), 1995–2024. 26 years of May data.