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Antarctic Circle

The Antarctic Circle rings Antarctica and marks where the southern midnight sun begins. Here it is on the globe, with this year’s latitude, the stretches where it touches land, the research stations near it and how far any place is from it.

Latitude in 2026 (on January 1)

66° 33′ 50.8″ S

In decimal degrees: 66.56410° S

It drifts about 14.5 m south every year, because Earth’s axis is slowly straightening up.

How far away is it?

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Pick a place to see how far it is from the line and which side it’s on.

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Where it is and which way it’s moving

On January 1, 2026, the Antarctic Circle was at 66° 33′ 50.8″ S (66.56410° S): 90° minus the tilt of Earth’s axis (23° 26′ 09.2″), using the International Astronomical Union’s formula for the mean obliquity (IAU 2006).

Since the tilt shrinks by about 0.47″ a year, the circle creeps south, toward the pole, by about 14.5 m a year, or 0.9 mi (1.5 km) per century. South of the line lie 21.2 million km², 4.2% of Earth’s surface, including almost all of Antarctica.

Where it runs: mostly ocean

The circle is 9,932 mi (15,984 km) long, the same as the Arctic Circle, but it’s mostly sea: only 1,587 km touches land (10%), in 5 stretches of the Antarctic coast. The other 14,397 km crosses the Southern Ocean.

Countries, in order
Country Enters Leaves Over land
Southern Ocean 0.00° 50.20° E 2,229 km over sea
Antarctica 50.20° E 57.26° E 314 km
Southern Ocean and Davis Sea 57.26° E 85.08° E 1,235 km over sea
Antarctica 85.08° E 85.20° E 5.1 km
Davis Sea 85.20° E 91.61° E 285 km over sea
Antarctica 91.61° E 115.46° E 706 km 9 stretches of land plus 353 km of sea between its lands
Southern Ocean 115.46° E 125.25° E 435 km over sea
Antarctica 125.25° E 138.98° E 473 km 4 stretches of land plus 137 km of sea between its lands
Southern Ocean 138.98° E 65.72° W 6,895 km over sea
Antarctica 65.72° W 62.71° W 89 km 3 stretches of land plus 45 km of sea between its lands
Southern Ocean 62.71° W 0.00° 2,784 km over sea
Total 9,932 mi (15,984 km) · over land 1,587 km · over sea 14,397 km

Those stretches of coast lie in sectors claimed by several countries: Australia across most of East Antarctica, France in Adélie Land, and Argentina, Chile and the United Kingdom, whose claims overlap, on the Antarctic Peninsula. The 1959 Antarctic Treaty froze those claims, and most countries don’t recognize them.

Research stations near the circle

There are no cities or permanent residents in or around the circle, only research stations whose staff rotate. Russia’s Mirny station sits practically on the line, 0.8 mi (1.3 km) away according to Natural Earth’s coordinates. France’s Dumont d’Urville is 15 mi (24 km) away and Australia’s Casey 19 mi (31 km).

Station Distance Side
Mirny Station 0.8 mi (1.3 km) S
Dumont d'Urville Station 15 mi (24 km) S
Casey Station 19 mi (31 km) N
Rothera Research Station 69 mi (112 km) S
Mawson Station 73 mi (117 km) S
San Martín Base 108 mi (173 km) S
Palmer Station 125 mi (201 km) N
Davis Station 153 mi (247 km) S

The nearest real towns are in Tierra del Fuego: Puerto Williams (Chile) is 805 mi (1,296 km) from the circle and Ushuaia (Argentina) 815 mi (1,312 km).

Midnight sun in December, polar night in June

In the Southern Hemisphere the seasons are reversed. At the December solstice (around the 21st) the sun doesn’t set anywhere on the circle, and at the June solstice it doesn’t rise. The farther south you go, the longer that lasts: the South Pole gets about six months of daylight and six of night.

Because the atmosphere bends light and makes the sun look a little higher, the midnight sun can peek over the horizon up to about 90 km (56 mi) north of the circle.

Antarctic Circle facts

The first ship to cross the Antarctic Circle was James Cook’s Resolution, on January 17, 1773. It crossed twice more on that voyage, but Cook never sighted the continent.

Antarctica isn’t entirely inside the circle: the Antarctic Peninsula and a few bits of coast poke out to the north. That’s why several of the most visited stations, like Palmer, lie outside the line.

Frequently asked questions

What is the exact latitude of the Antarctic Circle?

66° 33′ 50.8″ S (66.56410° S) on January 1, 2026. Every year it moves about 14.5 m closer to the South Pole.

Which countries does it pass through?

None: only Antarctica. The stretches of coast it crosses lie in sectors claimed by Argentina, Australia, Chile, France, and the United Kingdom, claims frozen by the Antarctic Treaty.

Does anyone live inside the Antarctic Circle?

Not permanently. There are research stations with rotating staff, more of them in summer than in winter.

What’s the closest town?

Puerto Williams (Chile), 805 mi (1,296 km) away, and Ushuaia (Argentina), 815 mi (1,312 km) away.

Is all of Antarctica inside the circle?

Almost all of it, but not quite: the Antarctic Peninsula and a few capes along the coast lie north of the line.

Related tools

All tools
Equator map See exactly where the equator runs, which countries it crosses and how far any place is from it. Tropic of Cancer Follow the Tropic of Cancer around the globe and see which countries and cities it passes through. Tropic of Capricorn Follow the Tropic of Capricorn around the globe and see which countries and cities it passes through. Arctic Circle See where the Arctic Circle runs, which countries it crosses and where the midnight sun begins.

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