Burkina Faso has a primarily tropical climate with two very distinct seasons. In the rainy season, the country receives between  of rainfall; in the dry season, the harmattan – a hot dry wind from the Sahara – blows. The rainy season lasts approximately four months, May/June to September, and is shorter in the north of the country. Three climatic zones can be defined: the Sahel, the Sudan-Sahel, and the Sudan-Guinea. The Sahel in the north typically receives less than  of rainfall per year and has high temperatures, .