The annual climate ranges from months of dry temperate weather during winter to humid subtropical weather interspersed with drier periods of hot weather during summer. In summer, which lasts from October to March, temperatures rise to about 93 °F (34 °C) in the extreme north and southwest, the warmest parts of the country. In winter, which lasts from April to September, there is frequent frost at night, and temperatures may fall to near freezing in some high-altitude areas during the day. Summer is heralded by a windy season, the winds carrying dust from the Kalahari, from about late August to early October. Annual rainfall, brought by winds from the Indian Ocean, averages 18 inches (460 mm), representing a range from 25 inches (635 mm) in the extreme northeast to less than 5 inches (127 mm) in the extreme southwest. The rains are almost entirely limited to summer downpours between December and March, which also mark the season for plowing and planting. Cyclic droughts, often lasting up to five or six years in every two decades, can limit or eliminate harvests and reduce livestock to starvation.

Plant and animal life

The Kalahari sandveld has often been called “thirstland” to distinguish it from true desert. Even in its southwestern corner, where there are some bare sand dunes, the vegetation is more characteristic of dry steppe than desert.

The general vegetation of the country is savanna grassland with yellow or light brown grass cover (turning green after rains) and woody plants. The savanna ranges from acacia shrub savanna in the southwest through acacia thornbush and tree savanna “parkland” into denser woodland and eventually forest as one moves north and east. Croton and Combretum tree savanna is found on the rocky hills of the eastern hardveld. Acacia tree savanna merges northward into mopane (African ironwood) savanna woodland. Mopane woodland covers most of the northern and eastern third of the country, with the exception of the open grasslands immediately surrounding the Okavango delta and Makgadikgadi Pans.

Animal life is extremely varied in a thirstland environment. About 150 species of mammals are found in Botswana. These range from 30 species of bats and 27 of rodents to more than 30 species of large mammals. Birdlife is prolific, with more than 460 species. Botswana has a great variety of reptiles and amphibians, of which more than 200 species have been described in detail. The principal fish, in the rivers of the north, are tilapia (African bream), catfish, and the tigerfish, which is famous for its ferocious resistance to being caught on a line.

There are several national parks and game reserves in Botswana, including the Central Kalahari Game Reserve—the largest reserve in the country and home to such animals as lions, black-backed jackals, elephants, foxes, ostriches, springboks, and zebras. Others include Chobe National Park, the Makgadikgadi Pans Game Reserve, and the Kgalagadi Transfrontier Park, a conservation area jointly managed by Botswana and South Africa.

Ethnic groups

The dominant ethnic identity in Botswana is Tswana, comprising some two-thirds of the population in the 21st century. The country’s whole population is characterized as Batswana (singular Motswana) whatever their ethnic origin. Tswana ethnic dominance (“Tswanadom”) in Botswana can be dated to the eight Tswana states, which ruled most of the area in the 19th century. Under British colonial rule, the populations of these states were given the official status of “tribes,” a term still used today.

Within southeastern Botswana the other main ethnic identity besides Tswana, that of the Khalagari (Western Sotho), has become so incorporated as to be almost indistinguishable from the Tswana. Even their name is now usually rendered in the Tswana form as “Kgalagadi.”

The Ngwato of east-central Botswana constitute the largest traditional “tribal” state but are probably less than one-fifth ethnic Tswana by origin. The major incorporated ethnic groups are Khalagari, Tswapong and Birwa (both Northern Sotho), and Kalanga (Western Shona). With larger numbers to the east in Zimbabwe, some Kalanga have resisted full incorporation.

The Tawana state of northwestern Botswana can be seen as the least successful in incorporating other ethnic groups. Most of its population is Yei and Mbukushu by origin, related to riverine peoples in the Caprivi Strip, Angola, and Zambia to the north. Smaller numbers of Mbanderu and Herero have greater numbers of close relatives across the border in Namibia. The Subiya along the Chobe, closely related to people in the Caprivi Strip and Zambia, were excluded from the Tawana “tribal” reserve by the British.

Small scattered groups of Khoisan people inhabit the southwestern districts of Botswana, as well as being incorporated with other ethnic groups. They include communities with their own headmen and livestock, as well as poorer groups employed by Tswana and white cattle farmers.

White settlement in Botswana, consisting of some Afrikaners and fewer English settled in border farms, totaled fewer than 3,000 people in the colonial period. The number of whites in Botswana, while showing some increase since independence, still accounts for only a very small portion of the total population. Botswana is also home to a small population of Asian or mixed ancestry.

Languages

The national language, Tswana (Setswana, Sechuana), is widely spoken. The official language is English. The Khoisan speak languages characterized as Khoe, or Khwe, and San. Several other languages are also spoken in the country, including Kalanga, Sekgalagadi, Herero, Mbukushu, and Yei.