Heavy rains have hit Johannesburg, affecting roads across the city. Weather forecaster Siyabonga Mthethwa said it would only clear up on Wednesday afternoon.

"These thunderstorms will break during the day. We are expecting a dry spell from 12pm until 5pm, when we expect another episode of thunderstorms later in the afternoon," he said.

One woman, travelling in Fourways, said the roads were slippery and dangerous.

"There is lots of deep running water in the roads and it is quite misty. Traffic is slow in all directions," she said.