March in St Petersburg is the windiest and the sunniest month of the year. In March, the weather in St Petersburg is typically warm. Average daily high temperature in March is about 22 degrees above zero. On average, St Petersburg has 23 sunny, 5 partly cloudy, and 3 rainy days in March. The rains are usually moderate. March as well as April, November, and December is considered the most comfortable time to visit St Petersburg.