April in Sioux City averages a daily high of 16.7°C with nights around 2.6°C. Expect roughly 10 wet days totalling 78.1mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Sioux City is September–October.
Based on SIOUX CITY AIRPORT, IA US (12.2km), 1995–2024. 30 years of April data.