January in Winterthur averages a daily high of 3.6°C with nights around -1.1°C. Expect roughly 13 wet days totalling 66.1mm. A hard month to visit for comfort alone.
Across the year, the best time to visit Winterthur is May–September.
Based on ZUERICH FLUNTERN, SZ (18.1km), 1995–2024. 29 years of January data.