April in Lemont is the windiest month of the year. In April, the weather in Lemont is typically warm. Average daily high temperature in April is about 14 degrees above zero. On average, Lemont has 14 rainy, 7 sunny, 6 partly cloudy, and 3 cloudy days in April. The rains are usually heavy. April as well as February, March, June, and December is considered the most uncomfortable time to visit Lemont.