Severe winter weather in the Western Cape poses a threat to Eskom's network, the power utility warned on Monday.
In a statement, Eskom said strong winds, extreme cold and heavy rainfall could affect electricity supply, potentially leaving some customers with prolonged periods without power.
The South African Weather Service (SAWS) warned that disruptive rainfall could be expected in Cape Town, Stellenbosch, Theewaterskloof and Witzenberg.
Between 30mm to 40mm of rain was expected for Monday, alongside gale-force winds and dangerous coastal conditions. Waves were expected to reach a height of six metres.
There was also the strong possibility of disruptive snowfall, which could be as deep as 15cm over the highest mountain ranges, said the weather service.
Eskom, meanwhile, urged "customers to remain patient and follow the channels made available to log a fault".
"Eskom will prioritise its response based on the size and duration of the faults," the statement said.
Large faults on the MV and HV network that affect a large number of customers would be prioritised.
Eskom said faults that left "single customers" without electricity supply for more than 48 hours would take priority, and thereafter, faults for more than 24 hours, until the most recent faults.
The effects of the storm are expected to be felt into Tuesday.