April in St. Louis averages a daily high of 20°C with nights around 9.2°C. Expect roughly 10.6 wet days totalling 113.2mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit St. Louis is April–May.
Based on ST LOUIS SCIENCE CENTER, MO US (6.3km), 1995–2024. 18 years of April data.