April in New Ulm is the rainiest month of the year. In April, the weather in New Ulm is typically warm. Average daily high temperature in April is about 12 degrees above zero. On average, New Ulm has 13 rainy, 6 sunny, 6 cloudy, and 5 partly cloudy days in April. The rains are usually heavy. April as well as January, March, and November is considered the most uncomfortable time to visit New Ulm.