The climate in Bhutan is influenced by altitude, monsoon winds, and exposure to sunlight. It ranges from subtropical in the lowlands to alpine in the high mountains. The southern region, along the Duars Plain and its foothills, is hot and humid, with abundant rainfall and tropical vegetation. The central region, where most of the population lives, has a temperate climate with mild winters and warm summers. The northern region, in the Great Himalayas, is cold and dry, with snow and ice covering the peaks and valleys. The average temperature varies from 6 °C in January to 22 °C in July in Thimphu, the capital city. Bhutan has a rich biodiversity of plants and animals, which are protected by several national parks and conservation areas.