January in Cagliari is the cloudiest month of the year. In January, the weather in Cagliari is typically warm. Average daily high temperature in January is about 12 degrees above zero. On average, Cagliari has 12 partly cloudy, 11 sunny, and 8 rainy days in January. The rains are usually moderate. January as well as February is considered the most uncomfortable time to visit Cagliari.