The prevailing wind directions of the KwaZulu-Natal coastal belt are predominatelty from the north east and south west. Winds from these broad sectors occur with frequencies in excess of 255 days a year. South westerly winds are generally stronger and may be accompanied by rain. Mean monthly wind speeds are lowest in May and June. Highest mean wind speeds occur in September and October, a transitional period at the end of winter. Maximum wind speeds occur in the early afternoon (14:00) and minimum wind speeds between 06:00 and 08:00.

The so called 'coastal low' is probably the best studied weather system affecting the coastline. Its formation is due to the interaction between large scale atmospheric flow and the marked South African escarpment. These systems propagate around South Africa moving northwards in an anticlockwise direction and are often associated with strong southwesterly gusts termed 'busters'. Rare northwesters in spring bring short periods of hot dry conditions.

Due to the latitudinal position of the region, it is influenced by both tropical and temperate weather systems. Intense frontal systems combined with the poleward flowing Agulhas Current can cause high energy swells along the coastline. Tropical cyclones are relatively rare but events such as Demoina and Imboa with the accompanying floods and gale force winds have caused severe catchment and coastal damage.

Local land/sea breezes and topographically-induced circulations are also significant wind systems in view of their effect on human climatic comfort and the dispersion or accumulation of air pollutants. Sea breezes, which are onshore north-easterly winds, blow for most of the day along the KwaZulu-Natal coast, particularly during the summer months. They strengthen the prevailing north-easterly gradient winds which are associated with typical anticylclonic circulation. They ventilate the coastal belt, and because they are associated with unstable atmospheric conditions, they favour the dispersion of pollutants. Sea breezes are known to extend inland as far as Cato Ridge and could thus move pollutants generated at the coast inland.

Land breezes develop at night and blow offshore as a north-westerly wind. They are light winds (1-2 ms^-1) and develop in a stable atmosphere. They combine with topographically induced winds to produce mountain-plain winds. At night, cooling leads to the development of mountain winds which blow down the longitudinal axes of the valleys. Under suitable conditions, these winds deepen during the night and overflow their interfluves, so that a sheet of cold, stable air now moves across KwaZulu-Natal towards the coast. This regional wind is known as the mountain-plain wind. It combines with the land breeze near the coast and so the offshore nocturnal wind at Durban may be a very deep stable layer.

The implications for air pollution dispersion are very important. Pollutants released in the interior of KwaZulu-Natal may travel vast distances towards the coast and because the air is stable, they are transported as thin fanning plumes for considerable distances without dispersion. By day, the circulation reverses and plain-mountain winds develop which blow from the coast to the interior. They are frequently not as well developed as their nocturnal counterparts.