If you’re looking forward to lots of outings with your partner, take a look at these details about year-round temperatures in Zelbio: The hottest months are usually July and August, with an average temperature of 17°C, while the coldest months are January and February, with an average of 2°C. The rainiest months in Zelbio are August, May, June and November, with each month seeing an average of 233 mm of rainfall.