January in Graz is the coldest month of the year. In January, the weather in Graz is typically cold. Average daily high temperature in January is about 2 degrees above zero. On average, Graz has 12 partly cloudy, 9 sunny, 8 cloudy, and 2 rainy days in January. The rains are usually light. January as well as February, November, and December is considered the most uncomfortable time to visit Graz.