The Arctic Circle is a circle of latitude encompassing the northernmost pole of the Earth and is located at approximately 66°33′45.6″ north of the Equator. The Arctic Circle is about 7,700,000 square miles. This line of latitude separates the Arctic zone in the north from the Northern Temperate Zone in the south. What makes the Arctic Circle in the north (and its counterpart in the south, the Antarctic Circle) unique from other regions on Earth is that the sun is below or above the horizon for a full 24 hours during the solstices, in June and December. In June the sun stays out constantly for an entire day and it is completely dark for 24 hours in December. Parts of the Arctic Circle might still see a reflection of the sun during a solstice because of atmospheric refraction and the angle of the Earth. Every year the actual location of the Arctic Circle (and therefore the Antarctic Circle as well) changes slightly due to Earth’s axial tilt, which is influenced by the orbit of the Moon and resulting changes in the tides of Earth’s bodies of water. There is an average shift of about 49 feet per year to the north.
The weather in the Arctic Circle is harsh, as are the long days and nights that categorize this particular region of the world. Although relatively few people reside in the Arctic Circle full time there are major cities including some in Russia and Norway that have between 70,000-310,000 people living in them all throughout the year. The migration of humans from harsh climates like the Arctic Circle from the areas of modern day Russia across the Bering Strait to areas of Alaska, Canada and southwards has been documented.
The Arctic Circle intersects eight nations including Scandinavia (Norway, Sweden), Denmark, Finland, Russia, the US, Canada, and Iceland. The water portions of the Arctic Circle cross the Arctic Ocean.