Previously whole of this state was called Baluchestan , but Iran symbolically added Sistan to the end of Baluchestan and then after the 1979's revolution in Iran , the name of province was changed to Sistan & Baluchestan without any excuse. Today, Sistan refers to the narrow strip of the northern margin of the province and Baluchestan involves whole Zahedan to Chabahar. Combined Sistan and Baluchestan province today accounts for one of the driest regions of Iran with a slight increase in rainfall from east to west, and an obvious rise in humidity in the coastal regions. The province is subject to seasonal winds from different directions, the most important of which are the 120-day wind of Sistan known as baluchi word "Levar", the seventh ("Gav-kosh") wind, the "Nambi" or south wind, the "Hooshak" wind, the humid and seasonal winds of the Indian Ocean, the North or ("Gurich") wind and the western ("Gard") wind. The province borders South Khorasan Province in the north, Kerman Province and Hormozgan Province in the west, the Gulf of Oman in the south, and Afghanistan and Pakistan in east.