The extreme cold in polar climates is caused by the Earth's tilt, resulting in a low angle of sunlight, especially during winter.

Polar climates experience extreme cold primarily due to the Earth's tilt on its axis. During the winter months, the poles are tilted away from the Sun, resulting in a low angle of sunlight that spreads energy over a larger area and reduces the amount of heat received. This leads to prolonged periods of darkness and very cold temperatures. Even during summer, the Sun remains low in the sky, providing limited warmth. This phenomenon, combined with the long winters and minimal solar energy, creates the harsh, freezing conditions typical of polar climates, found in regions like the Arctic and Antarctic.