December in Hermosillo is the coldest month of the year. In December, the weather in Hermosillo is typically warm. Average daily high temperature in December is about 23 degrees above zero. On average, Hermosillo has 21 sunny, 6 partly cloudy, 2 rainy, and 2 cloudy days in December. The rains are usually light. December as well as January and February is considered the most comfortable time to visit Hermosillo.