The savannah grasslands really have two distinct seasons, summer and winter. Fall and spring are periods of violent change in weather for the grasslands, when the weather shifts from the wet season into the dry season, or vice versa. Winter is the dry season in the savannah, and temperatures are slightly cooler during this period. The summers are hot and bring a lot of precipitation.
Spring in the African savannah brings violent thunderstorms and increased rainfall. The active weather, beginning in March, leads into the wet season. During this time, the temperatures warm up from the cool, dry winter to the wet, warm summer. They stay between 70 and 75 degrees Fahrenheit throughout the spring, gradually warming up to the 80 degrees and above days of the summer. During this season, some savannah grasses grow an inch in one day, according to the University of California Museum of Paleontology.
Summer is considered the wet, warm season of the savannah grasslands. Temperatures throughout the summer season in the savannahs remain above 80 degrees Fahrenheit. The heat evaporates moisture near the Earth, which rises and collides with the cooler moisture in the air above. This collision creates daily rains throughout the hot summers. The 20 to 50 inches of average annual rainfall in the savannahs occurs mostly in the six-to-eight-month wet season.
Winter is the dry season; the savannahs only average about four inches of rain during the entire dry season. December, January and February see no rain at all in the savannahs. Through the drought, only grasses survive. The winter temperatures are cooler, but rarely cold. They are usually between 65 and 70 degrees Fahrenheit and on occasion have dropped to 40 degrees Fahrenheit.
Like spring, autumn in the savannah grasslands is turbulent. The lightning from fall storms starts fires that burn through the grasslands. The fires are a necessary part of the savannah biome; they rejuvenate the soil and encourage new growth. Temperatures during this period are cooling from the hot 80 degree Fahrenheit summers to the 65 degree winters. They usually hover somewhere in the middle, around 75 degrees.