April in Calgary is the cloudiest month of the year. In April, the weather in Calgary is typically cold. Average daily high temperature in April is about 8 degrees above zero. On average, Calgary has 10 rainy, 9 partly cloudy, 7 cloudy, and 4 sunny days in April. The rains are usually moderate. April as well as March, May, June, and November is considered the most uncomfortable time to visit Calgary.