Taking into account the local weather in Wellsville is an important factor for planning your visit, especially if you plan to spend your trip poolside. The hottest months are usually July and August with an average temp of 68°F, while the coldest months are January and December with an average of 26°F. The snowiest months in Wellsville are January, December, March, and February, with each month seeing an average of 9 inches of snowfall.