October in Waukegan averages a daily high of 16.1°C with nights around 6.1°C. Expect roughly 11.7 wet days totalling 83.9mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Waukegan is May–September.
Based on CHICAGO WAUKEGAN REGIONAL AIRPORT, IL US (7.1km), 1995–2024. 26 years of October data.