April in Naperville is the rainiest and the windiest month of the year. In April, the weather in Naperville is typically warm. Average daily high temperature in April is about 13 degrees above zero. On average, Naperville has 15 rainy, 7 partly cloudy, 6 sunny, and 2 cloudy days in April. The rains are usually heavy. April as well as March, November, and December is considered the most uncomfortable time to visit Naperville.