Final answer:
The polar regions do not receive the most sun rays throughout the year due to the low angle of sunlight, which is more pronounced in the winter. In the summer, they experience continuous daylight for 24 hours, but the angle still provides only moderate warmth. Earth's orbit variation does not preferentially affect the poles.
Step-by-step explanation:
The polar regions do not receive the most sun rays throughout the year. This is because the angle of sunlight in the polar regions, such as the Arctic and Antarctic Circles, is very low, causing the rays to spread out over a larger area and therefore diminish in intensity. In contrast, during the summer solstice, regions within 23° of the poles experience continuous daylight for 24 hours a day, but even then, the sunlight comes in at a low angle, providing only moderate warmth.
In the winter, the sun is low in the sky and the polar regions receive the least sunlight, further reducing the amount of heat they receive. It's even possible for the temperature to remain below freezing even while the sun is up for 24 hours during the summer, simply because the sunlight arrives at such an oblique angle and lacks intensity.
The Earth's orbit is slightly elongated, which means the Earth comes closest to the sun around January, but this affects the entire Earth and actually serves to moderate northern hemisphere winters, without preferentially warming the polar regions.