Coordinates: 0°N 90°W / 0°N 90°W
Western Hemisphere is a geographical term  for the half of  Earth which lies west of the prime meridian (which crosses Greenwich, London, United Kingdom) and east of the antimeridian. The other half is called the Eastern Hemisphere.
As an example of
totum pro parte, the term Western Hemisphere is widely used by the United States government to mean the Americas.       
The Western Hemisphere consists of the
Americas, the western portions of Europe and Africa, the extreme eastern tip of Siberia ( Russia), numerous territories in Oceania, and a portion of Antarctica, while excluding some of the Aleutian Islands to the southwest of the Alaskan mainland.
In an attempt to define the Western Hemisphere as the parts of the world which are not part of the
Old World, there also exist projections which use the 20th meridian west and the diametrically opposed 160th meridian east to define the hemisphere. This projection excludes the European and African mainlands and a small portion of northeast  Greenland, but includes more of eastern Russia and Oceania.
The center of the Western Hemisphere is located in the
Pacific Ocean at the intersection of the 90th meridian west and the Equator, among the Galápagos Islands. The nearest land is Genovesa Island at .
0°19′00″N 89°57′00″W / 0.316667°N 89.95°W
highest mountain in the Western Hemisphere is Aconcagua in the Andes of Argentina at 6,960.8 metres (22,837 ft).
Sovereign states in both hemispheres
Below is a list of the sovereign states which are in both the Western and Eastern Hemispheres on the
IERS Reference Meridian, in order from north to south:
Denmark (due to Greenland and the Faroe Islands; mainland Denmark lies entirely in the Eastern Hemisphere).
Norway (due to Jan Mayen; mainland Norway lies entirely in the Eastern Hemisphere).
United Kingdom, passing through Greenwich, London. Most of the country is in the Western Hemisphere.
France, passing through Puynormand ( Gironde.) About 1/3 of the country, including cities like Nantes or Bordeaux, lies in the Western Hemisphere.
Spain, passing through Castelló de la Plana ( Valencian Community.) Most of Spain, including the capital Madrid, the Canary Islands and the southern half of its Mediterranean territorial waters, lies in the Western Hemisphere. Spanish, Moroccan and Algerian Mediterranean waters are the only part of the Mediterranean Sea located in the Western Hemisphere.
Algeria, passing through Stidia. About 1/4 of the country including Oran, Algeria's second largest city, is in the Western Hemisphere.
Mali, passing through the municipal area of Gao. Most of Mali, including the capital Bamako, lies in the Western Hemisphere.
Burkina Faso, passing through Lalgaye. Most of the country, including the capital Ouagadougou, is in the Western Hemisphere.
Ghana, passing through Tema. Most of Ghana, including the capital Accra, lies in the Western Hemisphere. Togo, passing near Tami ( Savanes Region).
Below is a list of the sovereign states which are in both the Western and Eastern Hemispheres along the
180th meridian, in order from north to south. With the exception of the United States ( Wake Island), all of them are located on just one side of the International Date Line, which is curved around them.
One sovereign state has territory on both hemispheres, but neither the prime meridian nor the 180th meridian passes through its territory:
Countries and territories in the Western Hemisphere but not in the Americas
The following countries and territories lie outside the
Americas yet are entirely/mostly or partially within the Western Hemisphere:
^ a b
Olson, Judy M (1997), "Projecting the hemisphere", in Robinson, Arthur H; Snyder, John P (eds.), , Bethesda, MD: Cartography and Geographic Information Society, American Congress on Surveying and Mapping Matching the map projection to the need . - "Western Hemisphere", Merriam-Webster's Geographical Dictionary (3rd ed.), Springfield, Massachusetts: Merriam-Webster, 2001, p. 1294 .
(2nd ed.), London, UK: Oxford Dictionary of English Oxford University Press, 2006, p. 2001 - "Western /western%20hemisphere", Merriam Webster's Online Dictionary (based on Collegiate vol., 11th ed.), Springfield, MA: Merriam-Webster, 2006
"Western Hemisphere", Britannica.com
Bureau of Western Hemisphere Affairs, United States Department of State.
Western Hemisphere, United States Department of the Treasury.
Western Hemisphere, Office of the United States Trade Representative.
Joe Biden: The Western Hemisphere Needs U.S. Leadership, Americas Quarterly, 17 December 2018.
Western Hemisphere, United States Department of Justice.
Western Hemisphere, United States Department of Agriculture.
Western Hemisphere, United States Fish and Wildlife Service.
Western Hemisphere, Fulbright Program.
"Informe científico que estudia el Aconcagua, el Coloso de América mide 6960,8 metros" [Scientific Report on Aconcagua, the Colossus of America measures 6960,8m] (in Spanish). Universidad Nacional de Cuyo. 2012. Archived from the original on September 8, 2012 . Retrieved . September 3, 2012