Residents have shared videos of ongoing rain accompanied by strong wind in Standerton, Mpumalanga, and big hailstones in Bethlehem, in the Free State.
Meteorologists from the Severe Weather and Information Service (Swaicsa) shared proof of a satellite image, showing that the storm forecast over parts of the country, is strengthening.
Affected areas are northern KZN, the eastern Free State, borders of Limpopo, Gauteng, and North West.
As a result, the Weather Service (SAWS) has warned against severe thunderstorms at level 2, for Gauteng, Limpopo and Mpumalanga.
Low lying areas and bridges are susceptible to flooding.
Picture: Supplied