Auckland is located in the North Island of New Zealand, is the largest and most populous urban area in the country with 1,377,200 residents, 31 percent of the country's population. Auckland has the largest Polynesian population of any city in the world.Auckland also straddles the Auckland Volcanic Field, which has produced about 50 volcanoes. These take the form of cones, lakes, lagoons, islands and depressions, and several have produced extensive lava flows. Most of the cones have been partly or completely quarried away. The individual volcanoes are all considered extinct, although the volcanic field itself is merely dormant. Auckland has at least 14 large lava tube caves which run from the volcanoes down towards the sea Auckland has a warm-temperate climate, with warm, humid summers and mild, damp winters. Under oceanic climate classification, the city has an moderate climate. It is the warmest main centre of New Zealand and is also one of the sunniest, with an average of 2060 sunshine hours per year. The average daily maximum temperature is 23.7 °C. Auckland is popularly known as the "City of Sails" because the harbour is often littered with hundreds of yachts and has more per capita than any other city in the world, with around 135,000 yachts and launches. Around 60,500 of the country's 149,900 registered yachtsmen come from the Auckland Region. About one in three Auckland households owns a boat, while in auckland sailing is a must for any tourist.