March in St. John's is the coldest month of the year. In March, the weather in St. John's is typically warm. Average daily high temperature in March is about 26 degrees above zero. On average, St. John's has 16 sunny, 11 partly cloudy, and 4 rainy days in March. The rains are usually light. March as well as February is considered the most comfortable time to visit St. John's.