🌊 The Wettest Spot on Earth · and the Driest Island

Mt. Waialeale, the volcano that created Kauai, sits in the middle of the island and receives close to 460 inches of rain per year — placing it in serious contention for the wettest spot on Earth. The summit is almost perpetually wrapped in clouds. But the south shore, where the Grand Hyatt sits, is in the rain shadow of that same mountain and averages 300 sunny days a year. A half-hour drive separates two of the most extreme weather environments in the United States. The canyon you visited today exists precisely because of this hydrological paradox: Waialeale's rain floods the Waimea River, and the Waimea River spent four million years carving the canyon.

Kauai is geologically the oldest of the main Hawaiian Islands — roughly five million years compared to the Big Island's half-million. By the time the Big Island is even as old as Kauai is now, Kauai itself may be largely submerged. The Hawaiian Islands are moving northwest over a stationary volcanic hotspot; the ones you see today are the current expression of that process, and older islands to the northwest including Niihau and the string of tiny atolls extending toward Midway mark the path the chain has already travelled. Wailua Falls, where the day started, flows directly off the flanks of that ancient five-million-year-old shield.

The name "Kauai" is often translated as "place around the neck" or "season" depending on the source — the exact meaning is debated. But in Hawaiian oral tradition, Kauai appears in the creation chant Kumulipo as one of the first islands named. It was also the only major Hawaiian island that Kamehameha I never conquered militarily — two invasion fleets were turned back, one by a storm, one by a disease outbreak among his troops. Kauai eventually joined the Hawaiian Kingdom through negotiation rather than battle, which makes it, by a certain reading, the one island that agreed to join.