In April, the weather in Isa is typically cold. Average daily high temperature in April is about 4 degrees above zero. On average, Isa has 9 partly cloudy, 8 rainy, 6 sunny, 6 cloudy, and 1 snowy day in April. The rains are usually light. April as well as January, February, October, and November is considered the most uncomfortable time to visit Isa.