April in Rhinelander is the rainiest month of the year. In April, the weather in Rhinelander is typically cold. Average daily high temperature in April is about 7 degrees above zero. On average, Rhinelander has 15 rainy, 9 cloudy, 5 sunny, and 1 partly cloudy day in April. The rains are usually moderate. April as well as January, March, May, and October is considered the most uncomfortable time to visit Rhinelander.