January in Santander is the cloudiest and the coldest month of the year. In January, the weather in Santander is typically warm. Average daily high temperature in January is about 12 degrees above zero. On average, Santander has 16 rainy, 7 partly cloudy, 4 sunny, and 4 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 Santander.