The total area of the UAE is approximately 77,700 square kilometers. The largest amirate, Abu Dhabi, accounts for 87 percent of the UAE's total area (67,340 square kilometers). The smallest amirate, Ajman, encompasses only 259 square kilometers (see fig. 11).
The UAE stretches for more than 650 kilometers along the southern shore of the Persian Gulf. Most of the coast consists of salt pans that extend far inland. The largest natural harbor is at Dubayy, although other ports have been dredged at Abu Dhabi, Sharjah, and elsewhere. The UAE also extends for about ninety kilometers along the Gulf of Oman, an area known as the Al Batinah coast. The Al Hajar al Gharbi (Western Al Hajar) Mountains, rising in places to 2,500 meters, separate the Al Batinah coast from the rest of the UAE. South and west of Abu Dhabi, vast, rolling sand dunes merge into the Rub al Khali (Empty Quarter) of Saudi Arabia.
Climate: The UAE generally is hot and dry. The hottest months are July and August, when average maximum temperatures reach above 48° C on the coastal plain. In the Al Hajar al Gharbi Mountains, temperatures are considerably cooler, a result of increased altitude. Average minimum temperatures in January and February are between 10° C and 14° C. During the late summer months, a humid southeastern wind known as the sharqi makes the coastal region especially unpleasant. The average annual rainfall in the coastal area is fewer than 120 millimeters, but in some mountainous areas annual rainfall often reaches 350 millimeters. Rain in the coastal region falls in short, torrential bursts during the summer months, sometimes resulting in floods in ordinarily dry wadi beds. The region is prone to occasional, violent dust storms, which can severely reduce visibility.