January in Grenoble is the coldest month of the year. In January, the weather in Grenoble is typically cold. Average daily high temperature in January is about 3 degrees above zero. On average, Grenoble has 13 rainy, 9 sunny, and 9 partly cloudy days in January. The rains are usually heavy. January as well as February, March, April, and May is considered the most uncomfortable time to visit Grenoble.