September in Hammond averages a daily high of 24.8°C with nights around 13.2°C. Expect roughly 8.2 wet days totalling 82.2mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Hammond is August–September.
Based on PARK FOREST WATER, IL US (17.9km), 1995–2024. 30 years of September data.