April in Whistler is the rainiest month of the year. In April, the weather in Whistler is typically cold. Average daily high temperature in April is about 2 degrees above zero. On average, Whistler has 26 rainy, 2 snowy, 1 sunny, and 1 cloudy day in April. The rains are usually heavy. April as well as May, June, and October is considered the most uncomfortable time to visit Whistler.