The midnight sun is a natural phenomenon that occurs when the sun remains visible at midnight during the local summer months, either in places north of the Arctic Circle or south of the Antarctic Circle. At the time of the summer solstice (about 21 June in the Northern Hemisphere and 22 December in the Southern Hemisphere) the sun is visible (given fair weather), for the full 24 hours of the day.

The number of days per year with potential midnight sun increases the farther towards either pole one goes.

Although the extent of the visibility of the midnight sun is normally defined by the polar circles, in practice it can be seen as much as 55 miles outside of the polar circle. The exact latitudes of the farthest reaches of midnight sun depend on topography and vary slightly year-to-year.

Although not a major circle of latitude, the north pole, also known as the geographic north pole, is the point in the Northern Hemisphere where the Earth′s axis of rotation meets the its surface. This point is called the called the True North Pole, or just True North.

The north pole lies antipodally opposite to the south pole and defines geodetic latitude 90° North.

At true north, all directions point south and all of Earth′s longitude lines converge there. No time zone has been assigned to the North Pole, so any time can be used as the local time. Along tight latitude circles, east is counterclockwise and west is clockwise. The North Pole is at the center of the Northern Hemisphere.

The north pole is located in the Arctic Ocean amid waters that are permanently covered with constantly shifting sea ice and the depth has been measured at over 13,700 feet (4200 meters). The nearest land is usually said to be Kaffeklubben Island, off the northern coast of Greenland about 430 miles (700 km) away, however, there are some perhaps semi-permanent gravel banks that lie slightly closer.

The nearest permanently inhabited settlement is Alert on Ellesmere Island in Canada, which is located 508 miles (817 km) from the Pole.

Magnetic north is located at a different location than the axial north pole and its location depend entirely upon where the planet′s magnetic field point vertically downward, at such place as a three dimensional compass will point straight down. In 2023, the location of the magnetic north pole was at o 86.100°N 142.000°E.

Since the earth is associated with a geomagnetic field that has a North-South Pole, a magnetic compass, therefore, will approximately point toward the north. The pointing direction is slightly different from true north by an angle called the declination.

The Arctic Circle marks the northernmost point at which the center of the noon sun is just visible on the December solstice. The region north of this circle is known as the Arctic, and the zone just to the south is called the Northern Temperate Zone.

The area above the Arctic Circle is the Frigid Zone, or could be called perpetual winter.

The degrees of latitude of the Tropic of Cancer is the same degrees as the tilt of the Earth (and is the same degree of latitude as the Tropic of Capricorn which is south of the equator).

The Tropic of Cancer marks the southernmost limit of the Northern Temperate Zone and this temperate zone extends from the Tropic of Cancer to the Arctic Circle.

The temperate zones generally have wider temperature ranges throughout the year and more distinct seasonal changes compared to tropical climates, where such variations are often small.

The portion of the Earth between the Tropic of Cancer and the Tropic of Capricorn is referred to the as the Torrid Zone, known as the region of perpetual summer.

Also, between the two Tropic latitudes, and nowhere else on Earth, the Sun appears directly overhead twice per year; except at the Tropic circles, where in appears overhead only once each year.

The southern temperate zone extends from the Tropic of Capricorn to the Antarctic Circle.

Within both Temperate Zones, the northern and southern, is also where we have the yearly cycle of four seasons, except that a particular season occurs a half-year apart in the Northern and Southern Temperate Zones because of the 23 1/2 tilt of our Earth as it travels it's orbit around the Sun.

The Antarctic Circle marks the southernmost point at which the center of the midnight sun is just visible on the June solstice. Likewise the region south of this circle is known as the Antarctic, and the zone just to the north is called the Southern Temperate Zone.

Also not a major circle of latitude, the South Pole, also known as the Geographic South Pole or Terrestrial South Pole, is the southernmost point on Earth and lies antipodally on the opposite side of Earth from the North Pole, at a distance of 12,430 miles (20,004 km) in any directions. It is one of the two points where Earth′s axis of rotation intersects its surface.

The south pole is situated on the continent of Antarctica and is the site of the United States Amundsen–Scott South Pole Station, which was established in 1956 and has been permanently staffed since that year. The Geographic South Pole is distinct from the South Magnetic Pole, the position of which is defined based on the magnetic field of the Earth. The South Pole is the center of the Southern Hemisphere.