Friday's rand fell versus the U.S. dollar, which was near a five-month high as traders lowered their bets on a flurry of rate cuts this year.
The rand fell nearly 1% to 18.9050 against the dollar at 1537 GMT. The dollar index rose 0.66% against a basket of currencies.
Recent U.S. labor market and inflation data have lowered market expectations for a June Federal Reserve rate cut.
"High geopolitical risks in the Middle East are driving dollar demand," said TreasuryONE Currency Strategist Andre Cilliers.
This week, solid economic statistics supported the local currency, which has been pummeled by power disruptions and political uncertainty ahead of a May election.
February saw increased mining and manufacturing output in South Africa, while business confidence remained high.
Next week, domestic investors will focus on March inflation and retail sales. Stocks closed 0.2% higher for the Top-40 (.JTOPI) and almost flat for the wider all-share (.JALSH).
The yield on South Africa's benchmark 2030 government bond rose 5.5 basis points to 10.745%.
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