April in Newmarket is the sunniest month of the year. In April, the weather in Newmarket is typically warm. Average daily high temperature in April is about 12 degrees above zero. On average, Newmarket has 12 rainy, 7 partly cloudy, 6 sunny, and 5 cloudy days in April. The rains are usually moderate. April as well as January, February, March, and June is considered the most uncomfortable time to visit Newmarket.