Why is Antarctica colder than the Arctic?

Antarctica is significantly colder than the Arctic primarily due to the fundamental differences in their geography and elevation.1

• Land vs. Ocean: The Arctic is an ocean surrounded by land, whereas Antarctica is a high-altitude continent surrounded by ocean. The Arctic Ocean acts as a heat source that helps moderate the climate, a feature that has no counterpart at the South Pole.1
• Elevation: Antarctica is the world's highest continent, with an average elevation of about 7,200 feet (2,200 metres). This high altitude, combined with a vast, perpetually reflective ice sheet, intensifies the cold.21
• Isolation: During the winter, the freezing of the surrounding sea effectively doubles the size of the continent, pushing the moderating influence of the ocean nearly 1,800 miles away from the central polar plateau.1
• Heat Loss: Lacking a thick, water-vapor-rich atmosphere to trap heat, the Antarctic surface readily loses energy into space, leading to extreme surface cooling.1