June in Grande Prairie is the rainiest month of the year. In June, the weather in Grande Prairie is typically warm. Average daily high temperature in June is about 20 degrees above zero. On average, Grande Prairie has 13 rainy, 8 sunny, 7 partly cloudy, and 2 cloudy days in June. The rains are usually heavy. June as well as January, March, April, and October is considered the most uncomfortable time to visit Grande Prairie.