April in Rapid City averages a daily high of 13°C with nights around 1.1°C. Expect roughly 10.2 wet days totalling 54.3mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Rapid City is September.
Based on RAPID CITY WEATHER FORECAST OFFICE, SD US (1.8km), 1995–2024. 29 years of April data.