December in Yakima averages a daily high of 3.3°C with nights around -4.8°C. Expect roughly 10.8 wet days totalling 37.6mm. A hard month to visit for comfort alone.
Across the year, the best time to visit Yakima is May–June.
Based on YAKIMA AIRPORT, WA US (4.8km), 1995–2024. 30 years of December data.