April in Lake Geneva is the rainiest and the windiest month of the year. In April, the weather in Lake Geneva is typically warm. Average daily high temperature in April is about 12 degrees above zero. On average, Lake Geneva has 16 rainy, 6 sunny, 5 cloudy, and 3 partly cloudy days in April. The rains are usually heavy. April as well as March, May, and November is considered the most uncomfortable time to visit Lake Geneva.