January in Gronau averages a daily high of 5.3°C with nights around 0°C. Expect roughly 16.6 wet days totalling 69.9mm. A hard month to visit for comfort alone.
Across the year, the best time to visit Gronau is May–September.
Based on TWENTHE, NL (11.3km), 1995–2024. 30 years of January data.