June in Lemont is the rainiest month of the year. In June, the weather in Lemont is typically warm. Average daily high temperature in June is about 26 degrees above zero. On average, Lemont has 17 rainy, 10 sunny, and 3 partly cloudy days in June. The rains are usually heavy. June as well as February, March, April, and December is considered the most uncomfortable time to visit Lemont.