The climate of New Zealand is varied due to the country's diverse landscape. Most regions of New Zealand belong to the temperate zone with a maritime climate (Köppen climate classification: Cfb) characterised by four distinct seasons. Winters are relatively mild and summers comparatively cool. The main contributing factors are the Pacific Ocean and latitude, although the mountain ranges can cause significant climate variations in locations barely tens of kilometres from each other. Conditions vary from extremely wet on the West Coast of the South Island to almost semi-arid in Central Otago and subtropical in Northland.