The South African Weather Service (SAWS) warned against damaging winds and waves (Level 2) along the coast of KwaZulu-Natal, on Wednesday.
This could lead to disruptions to beach activities and make navigating the sea difficult.
Damaging waves (Level 1) are also expected between Alexander Bay and Plettenberg Bay, into Thursday.
Cloudy conditions accompanied by rain and thunder are expected over Mbombela, Polokwane, Durban, Richards Bay, Pietermaritzburg and KuGompo City in East London.