Taking into account the local weather in Altmar 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 66°F, while the coldest months are January and February with an average of 28°F. The snowiest months in Altmar are January, February, March, and December, with each month seeing an average of 14 inches of snowfall.