Saudi Arabia located on terrain feature Arabian Peninsula
Geography
Saudi Arabia occupies about 80 per cent of the Arabian Peninsula (the world's largest peninsula), lying between latitudes 16° and 33° N, and longitudes 34° and 56° E. Because the country's southern borders with the United Arab Emirates and Oman are not precisely marked, the exact size of the country is undefined. The United Nations Statistics Division estimates 2,149,690 km2 (830,000 sq mi) and lists Saudi Arabia as the world's 12th largest state. It is geographically the largest country in the Middle East and the Arabian Plate.Saudi Arabia's diverse geography is dominated by the Arabian Desert, associated semi-desert, shrubland, steppes, several mountain ranges, volcanic lava fields and highlands. The 647,500 km2 (250,001 sq mi) Rub' al Khali ("Empty Quarter") in the southeastern part of the country is the world's largest contiguous sand desert. Though there are lakes in the country, Saudi Arabia is the largest country in the world by area with no permanent rivers. Wadis, non-permanent rivers, however, are very numerous. The fertile areas are to be found in the alluvial deposits in wadis, basins, and oases. The main topographical feature is the central plateau which rises abruptly from the Red Sea and gradually descends into the Nejd and toward the Persian Gulf. On the Red Sea coast, there is a narrow coastal plain, known as the Tihamah parallel to which runs an imposing escarpment. The southwest province of Asir is mountainous, and contains the 3,133 m (10,279 ft) Mount Sawda, which is the highest point in the country. Saudi Arabia is home to more than 2000 dormant volcanoes. Lava fields in Hejaz, known locally by their Arabic name of harrat (the singular is harrah), form one of Earth's largest alkali basalt regions, covering some 180,000 square kilometres (69,000 sq mi), an area greater than the state of Missouri.Except for the southwestern regions such as Asir, Saudi Arabia has a desert climate with very high day-time temperatures during the summer and a sharp temperature drop at night. Average summer temperatures are around 45 °C (113 °F), but can be as high as 54 °C (129 °F) at its most extreme. In the winter the temperature rarely drops below 0 °C (32 °F) with the exception of mostly the northern regions of the country where annual snowfall, in particular in the mountainous regions of Tabuk province, is not uncommon. The lowest recorded temperature to date, −12.0 °C (10.4 °F), was measured in Turaif.In the spring and autumn the heat is temperate, temperatures average around 29 °C (84 °F). Annual rainfall is very low. The Southern regions differ in that they are influenced by the Indian Ocean monsoons, usually occurring between October and March. An average of 300 mm (12 in) of rainfall occurs during this period, which is about 60 per cent of the annual precipitation. Saudi Arabia is home to approximately 1300 islands.