January in Nampa averages a daily high of 4.1°C with nights around -3.4°C. Expect roughly 11.4 wet days totalling 36.7mm. A hard month to visit for comfort alone.
Across the year, the best time to visit Nampa is June.
Based on BOISE AIR TERMINAL, ID US (26.2km), 1995–2024. 30 years of January data.