April in Mostar is the rainiest month of the year. In April, the weather in Mostar is typically warm. Average daily high temperature in April is about 12 degrees above zero. On average, Mostar has 16 rainy, 9 sunny, 4 partly cloudy, and 1 cloudy day in April. The rains are usually heavy. April as well as January, February, March, and November is considered the most uncomfortable time to visit Mostar.