Around 98% of continental Antarctica is covered in ice up to 4.7 kilometres (2.9 mi) thick.[1] Antarctica's icy deserts have extremely low temperatures, high solar radiation, and extreme dryness.[2] Any precipitation that does fall usually falls as snow, and is restricted to a band around 300 kilometres (186 mi) from the coast. Some areas receive as little as 50mm of precipitation annually. The coldest temperature recorded on Earth was −89.4 °C (−128.9 °F) at Vostok Station on the Antarctic Plateau.[1] Organisms that survive in Antarctica are often extremophiles.[2]