January in Cortona is the cloudiest and the coldest month of the year. In January, the weather in Cortona is typically cold. Average daily high temperature in January is about 7 degrees above zero. On average, Cortona has 11 partly cloudy, 8 sunny, 6 rainy, and 6 cloudy days in January. The rains are usually light. January as well as February, November, and December is considered the most uncomfortable time to visit Cortona.