The Arctic Circle marks the latitude above which the sun does not set on the summer solstice, and does not rise on the winter solstice. At the North Pole, the sun rises once each year and sets once each year: there are six months of continuous daylight and six months of continuous night.
https://nsidc.org/cryosphere/arctic-meteorology/arctic.html
So above the Arctic Circle, there is a period during the winter when the sun remains below the horizon. The same is true of the Antarctic Circle during Southern Hemisphere winter. On June 21st, when the sun is directly over the Tropic of Cancer at noon, it is not visible from below the Antarctic Circle.
http://curious.astro.cornell.edu/physics/160-our-solar-system/the-earth/seasons/15-what-is-the-significance-of-the-tropic-of-cancer-tropic-of-capricorn-arctic-circle-and-antarctic-circle-beginner
The Arctic and Antarctic Circles are located at ±66.5 degrees latitude. Note that 66.5 + 23.5 equals 90 degrees. This means that on December 21, when the Sun is directly over the Tropic of Capricorn at noon, it will not be visible from the Arctic Circle.
http://curious.astro.cornell.edu/physics/160-our-solar-system/the-earth/seasons/15-what-is-the-significance-of-the-tropic-of-cancer-tropic-of-capricorn-arctic-circle-and-antarctic-circle-beginner
The five major parallels of latitudes from north to south are called: Arctic Circle, Tropic of Cancer, Equator, Tropic of Capricorn, and the Antarctic Circle. On a maps where the orientation of the map is either due north or due south, latitude appears as horizontal lines.
https://www.geolounge.com/latitude-longitude/
Latitude indicates the location of a place on Earth north or south of the Equator. Latitude is an angular measurement in degrees (marked with °) ranging from 0° at the Equator to 90° at the poles (90° N for the North Pole or 90° S for the South Pole).
http://www.lat34north.com/Cities/CitiesLatitude.cfm
Arctic and Antarctic Circles. The Arctic and Antarctic Circles are the parallels of latitude that are roughly 66.5 degrees (66° 33′ 44″ (or 66.5622°). The region above the Arctic Circle, which includes the North Pole, is known as the Arctic. The region south of the Antarctic Circle, which includes the South Pole, is known as the Antarctic.
https://www.geolounge.com/latitude-longitude/
What is the Arctic? This map shows three definitions of the Arctic: the tree line; the 10 degrees Celsius isotherm, and the Arctic Circle at 66° 34' North. Click on image for a higher resolution version. —Credit: Map courtesy The Perry-Castañeda Library Map Collection.
https://nsidc.org/cryosphere/arctic-meteorology/arctic.html
Arctic Circle: 66° 33' 39. N. The Arctic Circle is the parallel of latitude that runs 66° 33´ 39 (or 66.56083°) north of the Equator and is one of the five major circles of latitude that mark maps of the Earth. Everything north of this circle is known as the Arctic, and the zone just to the south of this circle is the Northern Temperate Zone.
http://www.lat34north.com/Cities/CitiesLatitude.cfm
The Arctic Circle is the circle formed by all points on Earth whose latitude is roughly 66.5° North. It goes all the way around the Earth at this latitude, and there is a … point on it at every longitude. The Arctic Circle itself is a parallel of latitude, at about 66.5° North.
http://www.answers.com/Q/What_degrees_of_latitude_are_the_arctic_circle
The Arctic Circle is the circle of constant latitude at roughly 66.5 degrees north. That's about 23.5 degrees south of the North Pole. To be precise, the Arctic Circles latitude runs at 66° 33′ 39″ (or 66.56083°) north of the Equator. It is the parallel of latitude that runs 66° 33′ 44″ (or 66.5622°) north of the Equator.
http://www.answers.com/Q/What_degrees_of_latitude_are_the_arctic_circle
what is the degree of the arctic circle
The globe of the Earth showing the Arctic Circle at 66.5 degrees north of the equator. The Arctic Circle is at 66.5 degrees.