Hawaii  is the most recent of the 50 U.S. states (joined the Union on August 21, 1959), and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean.

Hawaii’s diverse natural scenery, warm tropical climate, abundance of public beaches and oceanic surrounding, and active volcanoes make it a popular destination for tourists, surfers, biologists, and volcanologists alike. Due to its mid-Pacific location, Hawaii has many North American and Asian influences along with its own vibrant native culture. Hawaii has over a million permanent residents along with many visitors and U.S. military personnel. Its capital is Honolulu on the island of Oʻahu.

The state encompasses nearly the entire volcanic Hawaiian Island chain, which comprises hundreds of islands spread over 1,500 miles (2,400 km). At the southeastern end of the archipelago, the eight "main islands" are (from the northwest to southeast) Niʻihau, Kauaʻi, Oʻahu, Molokaʻi, Lānaʻi, Kahoʻolawe, Maui, and the island of Hawaiʻi. The last is by far the largest and is often called "The Big Island" to avoid confusion with the state as a whole. The archipelago is physiographically and ethnologically part of the Polynesian subregion of Oceania.

Hawaii is the 8th-least extensive, the 11th-least populous, but the 13th-most densely populated of the 50 U.S. states. Hawaii's coastline is approximately 750 miles (1,210 km) long, which is fourth in the United States after Alaska, Florida, and California.

Hawaii is one of two states that do not observe daylight saving time, the other being Arizona.

The Hawaiian language word Hawaiʻi derives from Proto-Polynesian *Sawaiki, with the reconstructed meaning "homeland"; Hawaiʻi cognates are found in other Polynesian languages, including Māori (Hawaiki), Rarotongan (ʻAvaiki), and Samoan (Savaiʻi). (See also Hawaiki).

According to Pukui and Elbert,"Elsewhere in Polynesia, Hawaiʻi or a cognate is the name of the underworld or of the ancestral home, but in Hawaiʻi, the name has no meaning."

Spelling of state name

A somewhat divisive political issue arose when the constitution of the state of Hawaii added Hawaiian as a second official state language: the exact spelling of the state's name, which in the islands' language is Hawai'i (the apostrophe marking a Hawaiian consonant, a cut-off of breath before the final i). In the Hawaii Admission Act that granted Hawaiian statehood, the federal government recognized Hawaii to be the official state name. Official government publications, as well as department and office titles, use the traditional Hawaiian spelling, with no symbols for glottal stops or vowel length. In contrast, some private entities, including a local newspaper, do use such symbols.

The title of the state constitution is "The Constitution of the State of Hawaii". In Article XV, Section 1 uses "The State of Hawaii", Section 2 "the island of Oahu", Section 3 "The Hawaiian flag", and Section 5 specifies the state motto as "Ua mau ke ea o ka aina i ka pono". Since these documents predate the modern use of the ʻokina and the kahakō in Hawaiian orthography, the diacritics were not used.

An archipelago situated some 2,000 mi (3,200 km) southwest of the North American mainland,Hawaii is the southernmost state of the United States and the second westernmost state after Alaska. Only Hawaii and Alaska do not share a border with another U.S. state.

Hawaii is the only state of the United States that is not geographically located in North America, grows coffee, is completely surrounded by water, is entirely an archipelago, has royal palaces, and does not have a straight line in its state boundary.

Hawaii’s tallest mountain, Mauna Kea, stands at 13,796 ft (4,205 m) but is taller than Mount Everest if followed to the base of the mountain, which, lying at the floor of the Pacific Ocean, rises about 33,500 ft (10,200 m).

The eight main islands, Hawaiʻi, Maui, Oʻahu, Kahoʻolawe, Lanaʻi, Molokaʻi, Kauaʻi and Niʻihau are accompanied by many others. Kaʻala is a small island near Niʻihau that is often overlooked. The Northwest Hawaiian Islands are a series of nine small, older masses northwest of Kauaʻi that extend from Nihoa to Kure that are remnants of once much larger volcanic mountains. There are also more than 100 small rocks and islets, such as Molokini, that are either volcanic, marine sedimentary or erosional in origin, totaling 130 or so across the archipelago.

Geology

All the Hawaiian islands were formed from volcanic activity initiated at an undersea magma source called a hotspot. As the tectonic plate beneath much of the Pacific Ocean moves to the northwest, the hot spot remains stationary, slowly creating new volcanoes. Due to the hotspot’s location, the only active volcanoes are located around the southern half of the Big Island. The newest volcano, Lōʻihi Seamount, is located south of the Big Island’s coast.

The last volcanic eruption outside the Big Island occurred at Haleakalā on Maui before the late 18th century, though it could have been hundreds of years earlier. In 1790, Kīlauea exploded with the deadliest eruption (of the modern era) known to have occurred in what is now the United States. As many as 5,405 warriors and their families marching on Kīlauea were killed by that eruption.

Volcanic activity and subsequent erosion have created impressive geological features. The Big Island has the third highest point among the world’s islands.

Slope instability of the volcanoes has generated damaging earthquakes with related tsunamis, particularly in 1868 and 1975. Steep cliffs have been caused by catastrophic debris avalanches on the submerged flanks of ocean island volcanos.

Flora and fauna

Because the islands are so far from other land habitats, life before human activity is said to have arrived by the “3 W’s”: wind (carried through the air), waves (brought by ocean currents), and wings (birds, insects, and whatever they brought with them). This isolation, and the wide range of environments (extreme altitude, tropical climate) produced a vast array of endemic flora and fauna (see Endemism in the Hawaiian Islands). Hawaii has more endangered species and has lost a higher percentage of its endemic species than any other U.S. state.