Visiting local bars in Marathon is more fun when the weather is good. These temperatures and rainfall averages can help you determine the best time for bar-hopping. The hottest months are usually July and August, with an average temperature of 18°C, while the coldest months are January and February, with an average of -3°C. The snowiest months in Marathon are January, March, December and February, with each month seeing an average of 26 cm of snowfall.