Egypt lies within the zone of great tropical deserts, and except for the Mediterranean littoral has an arid climate with a great diurnal range of temperature and a high amount of sunshine throughout the year.
The weather is very stable and there are two well-defined seasons: the hot summer (May-October) and the cooler winter (November-April).
In the desert, summer daytime temperatures exceed 38°C but heat escapes into the cloudless sky at night, when temperatures fall by 14 or 17°C.
Winter temperatures are substantially lower, the January mean being between 13 and 16°C. Years may pass without any rainfall and then a sudden storm might give one or two inches. In spring, occasional depressions from the Sahara cross Egypt towards the Delta, bringing the khamsin, a dry scorching wind notorious for dust and sand storms.
Unlike the interior, the Mediterranean coast receives fairly regular, if small, winter rainfall (100 to 200 mm). The coast also has milder winters and rather lower summer temperatures than the interior through the tempering effect of the sea.
Sparse scrub finds a roothold on wadi floors within the desert, especially east of the Nile, but most of the deserts' sandy, gravelly or rocky surface is bare of vegetation. Desert plants include coarse grass, stunted tamarisks and dwarf mimosas. Date palms flourish in the Nile Valley and in oases, where subterranean water is found near the surface. Large desert mammals include gazelles, hyenas and jackals; mongooses live in the Delta. Among birds, kites, hawks and vultures are common, and the Nile and the Delta lakes attract waterbirds that include cranes, kingfishers and spoonbills.