Situated in the heart of the Highveld, Gauteng is the smallest province in South Africa, with only 1.4% of the land area, but it is highly urbanised, containing the cities of Johannesburg and Pretoria. As of 2007, it had a population of nearly 10.5 million, making it the most populous province in South Africa.
Gauteng’s southern border is the Vaal River, which separates it from the Free State. It also borders on North West to the west, Limpopo to the north, and Mpumalanga to the east. Gauteng is the only landlocked province of South Africa without a foreign border. Most of Gauteng is on the Highveld, a high-altitude grassland. Between Johannesburg and Pretoria there are low parallel ridges and undulating hills, some part of the Magaliesberg Mountains and the Witwatersrand. The north of the province is more subtropical, due to its lower altitude and is mostly dry savanna habitat.
The climate is mostly influenced by altitude. Even though the province is at a subtropical latitude, the climate is comparatively cooler, especially in Johannesburg, at 1,700 m above sea level (Pretoria is at 1,330m). Most precipitation occurs as brief afternoon thunderstorms; however, relative humidity never becomes uncomfortable. Winters are crisp and dry with frost occurring often in the southern areas. Snow is rare, but it has occurred on some occasions in the Johannesburg metropolitan area.
Johannesburg averages: January maximum: 26°C (min: 15°C), June maximum: 16°C (min: 4°C), annual precipitation: 713 mm
Pretoria averages: January maximum: 29°C (min: 18°C), June maximum: 19°C (min: 5°C), annual precipitation: 674 mm