April in New Haven is the windiest month of the year. In April, the weather in New Haven is typically warm. Average daily high temperature in April is about 14 degrees above zero. On average, New Haven has 11 rainy, 9 sunny, 7 partly cloudy, and 3 cloudy days in April. The rains are usually heavy. April as well as January, February, March, and October is considered the most uncomfortable time to visit New Haven.