The Middle East generally has a hot, arid climate, especially in the Peninsula and Egyptian regions. Several major rivers providing irrigation to support agriculture in limited areas here such as the Nile Delta in Egypt, the Tigris and Euphrates watersheds of Mesopotamia, and most of what is known as the Fertile Crescent. Conversely the Levantine coast and most of Turkey have more temperate, oceanic and wetter climates.
The Caucasus is divided into the North Caucasus and South Caucasus, although the Western Caucasus also exists as a distinct geographic space within the North Caucasus. The Greater Caucasus mountain range in the north is mostly shared by Russia and Georgia as well as the northernmost parts of Azerbaijan. The crest of the Greater Caucasus forms a barrier between the temperate mid-latitude and the subtropical climatic zones by impeding the movement of cold air masses from the north into Transcaucasia and, conversely, that of warm air masses into Ciscaucasia from the south.