It forms the bulk of Kauai County, which also includes the small nearby islands of Kaʻula, Lehua, and Niʻihau.

The story relates that he named the island after a favorite son; a possible translation of Kauaʻi is "place around the neck", describing how a father would carry his child.

[11] In January 1778, British navigator James Cook made the first recorded contact between any European and the indigenous people of the Hawaiian Islands when he arrived at Kauai by accident while crossing the Pacific during his third voyage of exploration.

The British immediately observed similarities in language and culture between the Kauaians and the parts of Polynesia with which they were already familiar, such as Tahiti.

[12]: 312  Later, while investigating a location for the ships to anchor, a shore party was mobbed by a crowd, a shot was fired, and one Kauaian was killed.

The local people especially valued iron: even small amounts, such as a single nail, could be traded for plentiful food supplies.

Kamehameha tried to conquer Kauai in 1796, but stormy seas caused the attack from Oahu to be canceled and he was afterward distracted by events elsewhere.

But on Kamehameha's orders, and persuaded by other foreign traders, Kaumualiʻi abandoned his relationship with Schäffer and forced the Russians to leave Kauai.

[17] From 1906 to 1934 the office of County Clerk was held by John Mahiʻai Kāneakua, who had been active in attempts to restore Queen Liliuokalani to the throne after the U.S. takeover of Hawaiʻi in 1893.

He later sought a warmer land and purchased the leases to Mana and Kekaha, where he became a successful sugarcane plantation owner.

Rejuvenation of the volcano 0.6–1.40 million years ago left lava flows and cones over the eastern two-thirds of the island.

One of the wettest spots on earth, with an annual average rainfall of 460 in (38.3 ft; 11.7 m), is on the east side of Mount Waiʻaleʻale.

The rain has eroded deep valleys in the central mountains, carving out canyons with many scenic waterfalls.

[citation needed] The Na Pali Coast is an isolated center for recreation, including kayaking along the beaches and hiking on the trail along the coastal cliffs.

Kauaʻi's climate is tropical, with generally humid and stable conditions year-round, although infrequent storms cause severe flooding.

At Kōkeʻe State Park, 3,200–4,200 ft (980–1,280 m) ASL, day temperatures vary from an average of 45 °F (7 °C) in January to 68 °F (20 °C) in July.

Based on data for the period from 1931 through 1960, the average yearly precipitation was 460 in (11,700 mm) (U.S. Environmental Science Services Administration, 1968).

Guava, coffee, sugarcane, mango, banana, papaya, avocado, star fruit, kava, noni and pineapple are all cultivated on the island, but most agricultural land is used for raising cattle.

[37] Kauaʻi is home to the U.S. Navy's "Barking Sands" Pacific Missile Range Facility, on the western shore.

[40] By 2008, transition of energy sources and growth in generating capacity had occurred, with most of Kauaʻi's electricity produced by imported liquid petroleum.

KIUC integrated large-scale solar into its grid so that, during sunny daylight hours, 97% or more of its generation came from renewable sources.

KIUC offers $1,000 rebates to residential customers who have solar water heating systems installed on their homes.

The Pacific Missile Range Facility has a 6,006-foot runway that is closed to general aviation traffic, but could be used for an emergency landing.

It offers classes in Hawaiian language, hula, lei and cordage making, the lunar calendar, chanting, and trips to cultural sites.

A scene in the opening credits of popular TV show M*A*S*H was filmed in Kauaʻi (helicopter flying over mountain top).

The Descendants, a 2011 film, has major parts shot in Kauaʻi, where the main character and his cousins own ancestral lands they are considering selling.