April in Oak Lawn averages a daily high of 15.4°C with nights around 5.2°C. Expect roughly 12.4 wet days totalling 102.6mm. 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 April data.