January in Rockford averages a daily high of -1.3°C with nights around -9.6°C. Expect roughly 10.2 wet days totalling 41.7mm. A hard month to visit for comfort alone.
Across the year, the best time to visit Rockford is August–September.
Based on ROCKFORD GREATER ROCKFORD AIRPORT, IL US (8.7km), 1995–2024. 30 years of January data.