The Western Hemisphere consists of the
Americas, excluding some of the
Aleutian Islands to the southwest of the
Alaskan mainland; the westernmost portion of
Europe, both mainland and islands; the westernmost portion of
Africa, both mainland and islands; the
extreme eastern tip of the
Russian mainland and islands (
North Asia); numerous territories in
Oceania; and a large portion of
Antarctica.
In an attempt to match the Western Hemisphere more closely with the Americas, some sources use the
20th meridian west and the diametrically opposed
160th meridian east to define the hemisphere.[1][3] This definition excludes all of the European and African mainlands, but still includes some islands associated with these continents, more of eastern Russia and Oceania, and part of Antarctica. It includes all islands of Alaska, but excludes a small portion of northeast
Greenland. There is no hemisphere that includes all of the Americas while excluding all land outside of it, regardless of the meridians or points chosen to define it.
Sovereign states in both hemispheres
Below is a list of the sovereign states in both the Western and Eastern hemispheres on the
IERS Reference Meridian, in order from north to south:
Below is a list of additional sovereign states which are in both the Western and Eastern hemispheres along the
180th meridian, in order from north to south. (France is not listed below due to its inclusion above, though the meridian does pass
Wallis and Futuna.) With the exception of the United States (due to Wake Island, Guam and the Northern Mariana Islands), all of them are located on just one side of the
International Date Line, which curves around them.
Russia, passing through
Chukotka Autonomous Okrug. Its portion lying east of the 180th meridian is the only part of the country lying in the Western Hemisphere.
Kiribati, passing close to
Arorae. The country has both the
Equator and the 180th meridian (
antimeridian) crossing through its territory. It is the only country located in four hemispheres.
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abOlson, Judy M (1997), "Projecting the hemisphere", in Robinson, Arthur H; Snyder, John P (eds.),
Matching the map projection to the need, Bethesda, MD: Cartography and Geographic Information Society, American Congress on Surveying and Mapping,
archived from the original on 2016-03-14, retrieved 2020-03-03. - "Western Hemisphere", Merriam-Webster's Geographical Dictionary (3rd ed.), Springfield, Massachusetts: Merriam-Webster, 2001, p. 1294.