January in Guantanamo is the sunniest and the coldest month of the year. In January, the weather in Guantanamo is typically warm. Average daily high temperature in January is about 27 degrees above zero. On average, Guantanamo has 26 sunny, 3 partly cloudy, and 2 rainy days in January. The rains are usually light. January as well as February, March, and December is considered the most comfortable time to visit Guantanamo.