If you’re looking forward to lots of outings with your partner, take a look at these details about year-round temperatures in Barnaul: The hottest months are usually July and June, with an average temperature of 18°C, while the coldest months are January and February, with an average of -12°C. The snowiest months in Barnaul are March, February, January and December, with each month seeing an average of 129 cm of snowfall.