Palmyra Atoll is an unoccupied equatorial Northern Pacific atoll administered as an unorganized incorporated territory by the United States federal government. The variable temporary population of 4–20 "non-occupants" are staff and scientists employed by various departments of the US government and The Nature Conservancy, as well as a rotating mix of Palmyra Atoll Research Consortium scholars pursuing research.
Palmyra is one of the Northern Line Islands (southeast of Kingman Reef and north of Kiribati Line Islands), located almost due south of the Hawaiian Islands, roughly one-third of the way between Hawaii and American Samoa. The atoll is 4.6 sq mi (12 km2), and it is located in the equatorial Northern Pacific Ocean. Its 9 mi (14 km) of coastline has one anchorage known as West Lagoon.
The atoll consists of an extensive reef, two shallow lagoons, and some 50 sand and reef-rock islets and bars covered with vegetation—mostly coconut trees, Scaevola, and tall Pisonia trees.
The islets of the atoll are mostly connected. Sand Island and the two Home Islets in the west and Barren Island in the east are not. The largest island is Cooper Island in the north, followed by Kaula Island in the south. The northern arch of islets is formed by Strawn Island, Cooper Island, Aviation Island, Quail Island, Whippoorwill Island, followed in the east by Eastern Island, Papala Island, and Pelican Island, and in the south by Bird Island, Holei Island, Engineer Island, Tanager Island, Marine Island, Kaula Island, Paradise Island, and Home Island (clockwise). Average annual rainfall is approximately 175 in (4,400 mm) per year. Daytime temperatures average 85 °F (29 °C) year round.