Doesn't need to be, but you see it both ways, as well as Western hemisphere.
western hemisphere
The Western hemisphere is the is the largest hemisphere.
in the northern and Western Hemisphere
The Eastern Hemisphere lies opposite the Western Hemisphere.
Western Hemisphere
The U.S.A is in the Western Hemisphere. It is also in the northern hemisphereThe U.S. is in the western hemisphere.
Western Hemisphere
western hemisphere
Southern Hemisphere
The Western Hemisphere.
Mexico is in the Northern Hemisphere, and the Western Hemisphere.
Yes, Argentina is located in the western hemisphere. It is situated in South America, which is primarily in the western hemisphere.
Yes, you should capitalize "Northern Hemisphere" as it is a proper noun referring to a specific geographic region.
western hemisphere
Western
The US is in the Northern hemisphere, and in the Western hemisphere. :3
It is in the northern hemisphere and also the western hemisphere.