December in Oak Park averages a daily high of 3.4°C with nights around -3.6°C. Expect roughly 9.4 wet days totalling 49.2mm. A hard month to visit for comfort alone.
Across the year, the best time to visit Oak Park is May–June.
Based on CHICAGO MIDWAY AIRPORT, IL US (11.5km), 1995–2024. 28 years of December data.