January in Oshkosh averages a daily high of -3°C with nights around -11.5°C. Expect roughly 9 wet days totalling 34.1mm. A hard month to visit for comfort alone.
Across the year, the best time to visit Oshkosh is May–September.
Based on OSHKOSH, WI US (1.3km), 1995–2024. 30 years of January data.