Which desert is the largest hot desert on Earth, spanning much of North Africa?

The Sahara Desert is the largest hot desert on Earth, spanning much of North Africa.

The Sahara covers roughly 9.2 million square kilometres, extending across a broad belt from the Atlantic Ocean to the Red Sea. It includes parts of countries such as Algeria, Chad, Egypt, Libya, Mali, Mauritania, Morocco, Niger, Sudan and Tunisia. Its landscapes are varied, with sand seas, gravel plains, rocky plateaus, mountains, salt flats and scattered oases.

The desert is not uniformly covered by dunes; sand accounts for only part of its surface. The highest mountain in the Sahara is Emi Koussi, a volcanic massif in Chad. Rainfall is generally very low and irregular, but conditions have changed substantially over geological time.

During the African Humid Period, roughly between 11,000 and 5,000 years ago, much of today’s Sahara supported grasslands, lakes and wildlife. Rock art and archaeological evidence record human communities from that greener era. The Sahara is the world’s largest hot desert, but Antarctica is larger overall when cold polar deserts are included.