January in Bilbao is the rainiest month of the year. In January, the weather in Bilbao is typically warm. Average daily high temperature in January is about 11 degrees above zero. On average, Bilbao has 18 rainy, 7 partly cloudy, 4 sunny, and 2 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 Bilbao.