45°

45th parallel south

The 45th parallel south is a circle of latitude that is 45° south of the Earth's equator.

It is the line that marks the theoretical halfway point between the equator and the South Pole. The true halfway point is 16.2 km (10.1 mi) south of this parallel because Earth is not a perfect sphere, but bulges at the equator and is flattened at the poles.^[1]

Unlike its northern counterpart, almost all (97%) of it passes through open ocean. It crosses the South Atlantic Ocean, the Indian Ocean, Australasia (New Zealand and just south of Tasmania), the Southern Ocean, and Patagonia.

At this latitude, daytime lasts for 15 hours, 37 minutes during the December solstice and 8 hours, 46 minutes during the June solstice.

Around the world

Starting at the Prime Meridian and heading eastwards, the parallel 45° south passes through:

Co-ordinates	Country, territory or ocean	Notes
45°0′S 0°0′E / 45.000°S 0.000°E / -45.000; 0.000 (Prime Meridian)	Atlantic Ocean
45°0′S 20°0′E / 45.000°S 20.000°E / -45.000; 20.000 (Indian Ocean)	Indian Ocean
45°0′S 147°0′E / 45.000°S 147.000°E / -45.000; 147.000 (Pacific Ocean)	Pacific Ocean	Tasman Sea
45°0′S 167°8′E / 45.000°S 167.133°E / -45.000; 167.133 (New Zealand)	New Zealand	South Island, passing just north of the towns of Oamaru, Naseby, Cromwell and Queenstown, and through the small settlement of Becks
45°0′S 171°6′E / 45.000°S 171.100°E / -45.000; 171.100 (Pacific Ocean)	Pacific Ocean	Passing just south of Guamblin Island,  Chile
45°0′S 74°23′W / 45.000°S 74.383°W / -45.000; -74.383 (Chile)	Chile	Islands in the Chonos Archipelago including James Island and Melchor Island, and Moraleda Channel before reaching the mainland near Macá Volcano.
45°0′S 71°33′W / 45.000°S 71.550°W / -45.000; -71.550 (Argentina)	Argentina	Chubut Province
45°0′S 65°35′W / 45.000°S 65.583°W / -45.000; -65.583 (Atlantic Ocean)	Atlantic Ocean