October in Mount Prospect averages a daily high of 17.1°C with nights around 6.8°C. Expect roughly 10.8 wet days totalling 79.3mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Mount Prospect is May–September.
Based on CHICAGO PALWAUKEE AIRPORT, IL US (6.6km), 1995–2024. 27 years of October data.