- 50 millimetre(s)
- Antarctica ()
With an average precipitation of 50 millimetres (2 inches) water equivalent per annum, decreasing to lower values farther inland, the driest continent is Antarctica. More than 99% of the 14-million-square-kilometre (5.4-million-square-mile) continent is covered by the Antarctic Ice Sheet, but one of its driest areas is the extremely low-humidity McMurdo Dry Valleys – the largest ice-free region on the continent – which sit between the Transantarctic Mountains and the Ross Sea.
Antarctica is also the highest continent, with an average elevation of 2,194 metres (7,198 feet).
Due to the continent's low rainfall, the Antarctic Ice Sheet is technically the largest desert in the world, despite also being the largest single body of fresh water (most of it in the form of ice). The Sahara, meanwhile, is the largest hot desert.
The driest place overall is located in the Atacama Desert in Chile. Between 1964 and 2001, the average annual rainfall for the meteorological station in Quillagua was just 0.5 millimetres (0.019 inches).