Spotted in the Sahara The Sahara is the world's largest hot desert, covering most of North Africa, an area comparable to the United States or China, known for extreme heat, powerful winds, sparse rainfall, and diverse landscapes including sand dunes and stony plains, not just sand. It experiences vast temperature swings, even occasional snow in higher regions, and was once a green savanna, with evidence suggesting it's naturally shifting back towards green, according to sources like Britannica and Wikipedia.