Aswan Low Dam was summoned to Egypt by the Fatimid Caliph, Al-Hakim bi-Amr Allah, to regulate the flooding of the Nile, a task requiring an early attempt at an Aswan Dam. After his field work convinced him of the impracticality of this scheme, and fearing the Caliph's anger, he feigned madness. He was kept under house arrest from 1011 until al-Hakim's death in 1021, during which time he wrote his influential "Book of Optics". Following their 1882 invasion and occupation of Egypt, the British began construction of the first dam across the Nile in 1898. Construction lasted until 1902, and it was opened
Aswan remain above during the coldest month of the year while average low temperatures remain above . Winters are short, brief and extremely warm. Wintertime is very pleasant and enjoyable while summertime is unbearably hot with blazing sunshine although desert heat is dry. The climate of Aswan is extremely dry year-round, with less than of average annual precipitation. The desert city is one of the driest ones in the world, and rainfall doesn't occur every year, as of early 2001, the last rain there was seven years earlier. Aswan is one of the least humid cities on the planet, with an