St. Petersburg's climate is mild compared to that of the more inland areas of Russia. The city is on the Baltic Sea, which makes winters relatively mild, but summers are not particularly hot either. It is humid all year round.
They are long as in most areas of Russia. Temperatures as low as -10 Co are normal, and - 20 Co is not unusual. January temperatures average -8°C (17°F). The average winter temperature is -6.9 Co. The Neva River freezes between November 25 and December 5 and the ice is gone only by mid-April.
It can be quite long. From early April temperatures are above freezing and by April 15 all the snow normally melts. One should be prepared for some chilly rainy days, but it can get rather warm mid-May onwards.
Vary from year to year, but generally temperatures are somewhere near +20-25 Co. You ought to have some clear days to enjoy the White Nights. Hot sunny days are not rare, but you never know when it is going to rain. July is the hottest month of the year. It usually starts getting a bit cooler in mid-August. The highest temperature ever recorded in the city was +33.6 Co. During these months the city is packed with foreign and Russian visitors.
It starts with reasonably warm days in mid-September, but by mid-October it is often chilly. The average September temperature is 10.8 Co, and the average October temperature is 4.9 Co. In November it might start to snow, but sometimes it does not snow until mid-December.
WEATHER AVERAGES FOR STPETERSBURG