The easterly trade winds  from the Indian Ocean bring about 89cm of precipitation annually. The High Veld receives 38-76cm annually. This amount decreases rapidly toward the west. The western coast only has 5cm annually. The rainfall from the trade winds is mainly between October and April. The amount of rainfall varies greatly from year to year in drier regions of the plateau. The south-west is under the influence of western winds from the Atlantic Ocean. This region has about 56cm of rain between June and September.