Sahara Desert: Size, Temperature Extremes & Major Ergs
The Sahara: Earth's Largest Hot Desert by the Numbers
The Sahara Desert spans 9.4 million km² (3.6 million mi²)—comparable to China or the contiguous United States. It stretches across 11 North African countries from the Atlantic to the Red Sea.
Temperature Extremes
- Highest recorded: 57.8°C (136°F) – though disputed; reliably >50°C (122°F) in multiple locations.
- Average summer highs: 38–46°C (100–115°F).
- Diurnal swing: Can exceed 30°C (54°F) between day and night.
- Cause: Subtropical high pressure, intense solar angle, near-zero humidity, no cloud cover.
Major Sand Seas (Ergs)
| Erg | Location | Notable Features |
|---|
| Erg Chebbi | SE Morocco | Dunes >150 m; tourist hub (Merzouga) |
| Erg Chigaga | S Morocco | Wilder, less visited; 40 km long |
| Erg Iguidi | W Algeria | Massive crescentic (barchan) dunes |
| Grand Erg Oriental | Algeria/Tunisia | Vast, complex dune forms; oil fields beneath |
| Grand Erg Occidental | Algeria | Star dunes, linear dunes; extreme aridity |
| Erg Bilma | Niger | Salt mines, oasis towns (Bilma) |
Beyond Sand: Diverse Landscapes
- Hamada: Rocky plateaus (70% of Sahara).
- Reg: Gravel plains.
- Mountains: Tibesti (Chad, 3,415 m), Ahaggar (Algeria), Air (Niger).
- Oases: Siwa, Ghadames, Timbuktu fringe—fed by fossil aquifers.
Human Context
- Population density: <1/km² (mostly in oases, Nile Valley, coast).
- Tuareg, Berber, Arab, Toubou, Kanuri peoples.
- Climate change expanding desert southward (Sahel encroachment).
Wanderlust World