As far as rainfall is concerned, the southern region receives the largest amount of rainfall while the central plains receive the least. The temperatures average from 30 C (86 F) in January (summer) to 23 C (73 F) in July (winter). Please be aware that the maximum temperature can reach 47 C (117 F) (January) and 35 C (95 F) (July).
For your information, the average nightly temperature can range from 7-18 C (45-64 F) (January) and most certainly freezing in July. It is highly advisable to wear 'breathable' clothes to avoid heat exhaustion or stroke during the day, drink plenty of water and ensure that appropriate clothing is available in the often cold nights.
The varying climatic conditions impact on the type of vegetation in the ecosystem that can survive and flourish in each vegetation zone. This of course affects the distribution and population densities of the various animals - each type favouring some or other ecosystem environment.
The area in the North of the Olifants River to the Limpopo River is a the hottest and most arid of regions in the Kruger National Park. The Ecosystem's vegetation is dominated by the medium-sized Mopane Tree. The Mopane tree is untroubled by the poor, alkaline soil and erratic rainfall of the region. Nature has sensibly adapted the Mopane for such conditions: when the heat becomes unbearable, the leaves fold along the mid-rib.
This allows rays of the sun to pass directly to the ground and moisture in the tree is thus preserved. The tree casts a poor shadow but absorbs a minimum of heat. Its leaves are aromatic, tasting and smelling of turpentine, but they are nutritious and enjoyed by Antelope and Elephant.
The area south to the Olifants river on the eastern side of the Kruger National Park is dominated by acacia thorn trees. This area has a higher rainfall and therefore has more fertile soil than the area north of the Olifants river. Its sweettasting grasses offer excellent grazing and supports a high population of animals. It is the home of great herds of Impala, Zebra, Wildebeest, Buffalo and Giraffe.
The largest area in the Kruger Park is between the Crocodile and Olifants Rivers, immediately to the west of the acacia division. This ecosystem area also has sweet grazing and is a parkland inhabited by many Antelope. The Red Bush Willow Tree, Combretum Apiculatum, flourishes here.
The area in the Kruger Park between the Sabie and Crocodile Rivers receives approximately 760mm of rain a year and is thickly wooded with sour-tasting grass, less favoured by Antelope. There is a large variety of trees in this area including Acacias. Combretums grow in large numbers and there are giant Sycamore Fig, Mkuhlu, Maroela, Kiaat and spectacular flowering trees such as the White Pear and the red and orange Kaffirboom.
The smallest area in the Kruger National Park, South Africa, lies in the valleys of the Luvuvhu and Limpopo rivers, along the Kruger Park's northern boundary. This is an area of tropical, riverine forest consisting of huge Wild Fig, Spectral Fever Tree, Ebony, Mahogany, Ironwood, Wild Seringa and many Boabab. The Valley of the Giants is found in this region.