Certain provinces could experience flash floods due to heavy rain over the next two days, Weather SA said on Monday.
"Heavy falls leading to flash flooding are possible in the Free State, North West province, and the Western Cape for today," forecaster Madimetja Thema said.
Weather SA had also released a weather watch for potential flash floods in Gauteng for Monday night and Tuesday morning.
The heavy rain was expected to spread to the Eastern Cape on Tuesday, Thema said.
"It is expected to let up by Tuesday evening."