The Sahara: heat and size

The Sahara is the world’s largest hot desert, with area estimates of roughly 9.1–9.4 million km² depending on how its boundaries are defined. When cold polar deserts are included, it is commonly ranked third after the Antarctic and Arctic deserts. Calling it simply “the hottest desert” is imprecise: temperature records depend on whether air or land-surface temperature is measured, as well as season and location; satellite surface-temperature studies have repeatedly identified Iran’s Lut Desert as the hottest.