January in Mount Prospect averages a daily high of 0°C with nights around -7.6°C. Expect roughly 6.7 wet days totalling 32.2mm. A hard month to visit for comfort alone.
Across the year, the best time to visit Mount Prospect is May–September.
Based on CHICAGO PALWAUKEE AIRPORT, IL US (6.6km), 1995–2024. 28 years of January data.