Iran's plateau climate is relatively dry, and despite the country's location in the world's dry climate belt, the Alborz and Zagros mountain ranges prevent the entrance of humid streams from the Caspian and Mediterranean seas into Iran. The country's span across 25 and 40 degree latitude, and the varying height levels allow for a diversity of cli-mates. In the northwest, winters are cold with heavy snowfall and subfreez-ing temperatures. Spring and fall are relatively mild while summers are dry and hot.
In the south, winters are mild and summers are very hot, having average daily temperatures that exceed 38° C (100° F) in July. On the Khuzestan plain, summer heat is accompanied by high humidity.