Weather is probably a major factor when you plan your trip to Petrozavodsk, but bear in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually July and August, with an average temperature of 15°C, while the coldest months are January and February, with an average of -6°C. The snowiest months in Petrozavodsk are January, February, March and December, with each month seeing an average of 220 cm of snowfall.