There are two primary seasons in West Africa. The dry period can be further divided into two distinct seasons, mild and hot, particularly in the savanna and Sahelian regions of Mali. The rainy season usually begins in June and continues into October. Almost all of the annual rainfall occurs during this time. As much as 60-80 inches of rain may fall in the southern savanna but rainfall is lower further north. Temperatures range from 70 to 100 degrees Fahrenheit (21-40°C). The cool season lasts from December to mid-February, when temperatures range from 60 degrees Fahrenheit at night to the mid-80s (about 28-34°C) during the day. The hot season starts in mid-February and goes into June. The air is dry, dusty, and very hot; temperatures often reach over 100 degrees (40°C) and clouds of dust hang in the air. This is the season of the harmattan, the dry, sandy wind that brings dust clouds southwards from the Sahara.