Definition:Western Hemisphere

Definition
The western hemisphere of Earth is the hemisphere immediately to the west of the principal meridian.

Points in the western hemisphere have longitude between $0 \degrees \, \mathrm W$ (the principal meridian itself) and $180 \degrees \, \mathrm W$.

Also see

 * Definition:Terrestrial Hemisphere:
 * Definition:Northern Hemisphere
 * Definition:Southern Hemisphere
 * Definition:Eastern Hemisphere