October in St. Louis averages a daily high of 20.8°C with nights around 10°C. Expect roughly 8.5 wet days totalling 81mm. 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. 20 years of October data.