Iran’s climate is very varied in different areas. In the northwest, winters are very cold with heavy snowfall. Spring and fall are relatively mild, while summers are dry and hot. In the south, winters are very mild and the summers are very hot and humid, this gives visitors the chance to choose any kind of weather any time of the year.

In general, Iran has an arid climate in which most of the relatively scant annual rainfall falls from October through April. In most of the country, yearly rainfall averages 25 centimeters or less. The major exceptions are the higher mountain valleys of the Zagros and the Caspian coastal plain, where rainfall averages at least 50 centimeters annually. In the western part of the Caspian, rainfall exceeds 100 centimeters annually and is distributed relatively evenly throughout the year. This contrasts with some basins of the Central Plateau that receive ten centimeters or less of rainfall annually.

Iran is one of the only countries in the world which has the complete four seasons. In summer, the weather can be cool as well as warm, and in the cold winters, it can be mild. A large part of the country suffers great extremes of heat and cold between summer and winter and rainfall is mainly confined to winter and spring. Summers are warm to hot with virtually continuous sunshine, with high humidity on the southern coasts.