Hawaii is an island state in the Western United States, located in the Pacific Ocean about 2,000 miles from the U.S. mainland. It is the only U.S. state outside North America, the only one that is an archipelago, and the only one in the tropics. Hawaii is part of the Polynesian subregion of Oceania, and its ocean coastline is 750 miles long. It is the 50th state of the United States and has been since August 1959. Hawaii is the most recent state to join the union.