The meridian 90° west of Greenwich is a line of longitude that extends from the North Pole across the Arctic Ocean, North America, the Gulf of Mexico, Central America, the Pacific Ocean, the Southern Ocean, and Antarctica to the South Pole.
The 90th meridian west forms a great circle with the 90th meridian east, located midway between the Prime meridian and the 180th meridian; thus, the center of the Western Hemisphere is on this meridian.
One of the four 45 x 90 points is located in Rietbrock, Wisconsin, where the 45th parallel north intersects with the 90th meridian west, marking the halfway point between the 90° Latitude North, 180th Meridian East & West, 0° latitude, and 0° longitude.
From Pole to Pole
91st meridian west
|90th meridian west
forms a great circle with
90th meridian east
89th meridian west