July in Oak Lawn averages a daily high of 29.4°C with nights around 20°C. Expect roughly 9.9 wet days totalling 116.2mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Oak Lawn is August–September.
Based on CHICAGO MIDWAY AIRPORT 3 SW, IL US (3.3km), 1995–2024. 30 years of July data.