December in Lanzhou is the sunniest month of the year. In December, the weather in Lanzhou is typically cold. Average daily high temperature in December is about 2 degrees above zero. On average, Lanzhou has 20 sunny, 8 partly cloudy, 2 cloudy, and 1 snowy day in December. The snowfalls are usually light. December as well as January, February, and November is considered the most uncomfortable time to visit Lanzhou.