Best Period to Go: The climate of St. Petersburg is maritime and milder than its northern latitude. During the month of January it is -8 degree Celsius so it is a windy city and it is also not possible for some travelers to visit the city. The summer season is cool and it is also convenient for the tourists to visit this time of the year too. From June to August, one can also visit the city as it is warm during these months. The city experiences northern latitude which means one can get long summer days and long winter nights in St. Petersburg.