Weather can make or break a road trip, so here's some data about year-round temperatures in Usma to help you plan yours: The hottest months are usually July and August, with an average temperature of 16°C, while the coldest months are January and February, with an average of -1°C. The snowiest months in Usma are December, November, January and February, with each month seeing an average of 14 cm of snowfall.