Artic regions are cold because...?

Answer 1

Why they don't even see the sun for months at a time would probably be part of it. Plus even in the summer, the sun is so low in the sky, not as much of the sun's warmth gets there. Then, the prevailing winds usually don't "wash over" the poles and thereby mix warmer air in. They move more or less in circles around the poles.

Answer 2

bkc99xx hit on it, but it's primarily due to the low angle of the sun, even in "summertime" (yes, there's "summer" even near the poles).

Every spot on earth gets roughly the same hours of sunlight over a year, but the acute angle at which the sun's rays strike near the poles results in less infrared radiation warming those regions. (This is called insolation.)

Answer 3

The amount of sunlight that reaches the arctic regions is a lot less than other regions.