December in Yakima is the coldest month of the year. In December, the weather in Yakima is typically cold. Average daily high temperature in December is about 2 degrees above zero. On average, Yakima has 14 partly cloudy, 8 sunny, 6 cloudy, and 3 rainy days in December. The rains are usually light. December as well as January, February, and November is considered the most uncomfortable time to visit Yakima.