ABSTRACT
The Iranian plateau is situated in a dry geographic region. The dry climate of Northern Africa and the Middle East continues into Iran and Central Asia. Average precipitation in Iran is less than the world average. It should be noted that even though Iran is classified generally as a dry country, it includes many different climatic conditions. Iran can be divided into four basic climatic regions:
Northern shores (temperate climate): this region, which is to the south of the Caspian Sea, has the highest precipitation in the country and there are very dense forests in the highlands and intensive agriculture in the lowlands. It is cold in winter and hot and humid during the summer season. Average annual precipitation is about 1.5m. Relative humidity is above 70 per cent throughout the year.
Mountain and high plateau region (cold climate): the high mountain range of Alborz is situated to the north and Zagros is situated to the west of the country. This region is cold and dry in winter and mild and dry in summer. Average annual precipitation is about 30cm.
Southern shores (hot and humid climate): the hottest area of Iran is along the Persian Gulf and Oman seashores. It is mild in winter and hot and humid during the long summertime. In this region the average annual rainfall is less than 20cm and relative humidity is above 50 per cent throughout the year.
Central plateau (hot and dry climate): this region is larger than the other regions and covers most of the central Iranian plateau. It is cold and dry in winter and hot and dry in summer. Tehran, the capital of Iran is situated in this region.
