Compare the Poles: Seasons
Because of the earth's tilt and orbit around the sun, the poles receive less energy and heat from the sun. This results in only two polar seasons—summer and winter. In summer at the poles, the sun does not set, and in winter the sun does not rise.
The Earth is slightly tilted—that is what gives us our seasons.
Here’s how it works. On one side of its orbit around the sun, the Earth is tilted towards the sun. During this time, the northern hemisphere receives more heat so has higher temperatures—it is summer. Six months later, the Earth is on the other side of its orbit, and the Earth is tilted away from the sun. Now, the northern hemisphere receives less heat so it is colder—it is winter.
The Land of the Midnight Sun
The Arctic has often been referred to as the "Land of the Midnight Sun." The earth rotates around an axis that is tilted by approximately 23½° from the vertical. On the summer solstice (June 21st), all of the Earth's area north of the Arctic Circle (66°33’N) is bathed in sunlight for 24 hours. Conversely, on December 21st, the winter solstice, the opposite is true - the Arctic is completely shaded from the sun's light. So if it's sunny all day long in the summer, why doesn't it get very hot? (The summer mean high temperature in Barrow, Alaska is only 45°F!)