December in Des Plaines averages a daily high of 2.7°C with nights around -4.7°C. Expect roughly 10.6 wet days totalling 55.6mm. A hard month to visit for comfort alone.
Across the year, the best time to visit Des Plaines is August–September.
Based on CHICAGO OHARE INTERNATIONAL AIRPORT, IL US (9.1km), 1995–2024. 30 years of December data.