 Clinton County comprises the Lock Haven, PA Micropolitan Statistical Area, which is also included in the Williamsport-Lock Haven, PA Combined Statistical Area.According to the U.S. Census Bureau, the county has a total area of , of which is land and (1.0%) is water.The county has a humid continental climate which is warm-summer ("Dfb") except in lower areas near the West Branch and the Bald Eagle Creek which are hot-summer ("Dfa").