Question

Why do polar zones have cold temperatures year-round?

Answer 1

Low amount of solar radiation

Explanation:

At the poles during daylight the sun is always very low on the horizon. This means that the angle the suns rays strike the area is low as well. This results in less solar radiation reaching the surface per surface area.

Moreover in winter the nighttime is extremely long (at the poles it is six months of darkness) allowing for the temperature to drop.

Finally the presence of ice cover causes the albedo (how much radiation, including heat, is reflected back into space from the planet's surface) to be very high in the polar regions further reducing the temperature.