January in Sveti Vlas is the rainiest and the coldest month of the year. In January, the weather in Sveti Vlas is typically cold. Average daily high temperature in January is about 5 degrees above zero. On average, Sveti Vlas has 10 rainy, 8 sunny, 7 partly cloudy, and 6 cloudy days in January. The rains are usually heavy. January as well as February, March, and December is considered the most uncomfortable time to visit Sveti Vlas.