In April, the weather in Whistler is typically cold. Average daily high temperature in April is about 5 degrees above zero. On average, Whistler has 11 cloudy, 8 partly cloudy, 5 rainy, 4 sunny, and 2 snowy days in April. The rains are usually heavy. April as well as February, March, May, and June is considered the most uncomfortable time to visit Whistler.