January in Piraeus is the rainiest, the cloudiest, and the coldest month of the year. In January, the weather in Piraeus is typically warm. Average daily high temperature in January is about 11 degrees above zero. On average, Piraeus has 10 sunny, 10 partly cloudy, 9 rainy, and 2 cloudy days in January. The rains are usually light. January as well as February and December is considered the most uncomfortable time to visit Piraeus.