At 1631 GMT, the rand traded at 18.7750 against the U.S. dollar, about 0.5% stronger than its previous close. It was mostly unchanged in the earlier session after the South African Reserve Bank kept rates unchanged on Thursday.

The dollar was last down about 0.16% against a basket of currencies as U.S. data showed the annual increase in inflation was below 3% for a third straight month.

South Africa's consumer inflation fell for a second consecutive month in December, but the central bank said it did not yet see a strong enough trend to consider cutting rates.

The central bank highlighted that port and rail constraints were proving a major damper to economic growth. South Africa's Richards Bay Coal Terminal on Thursday said its coal exports had hit their lowest level since 1992 as the country's freight rail crisis continues to throttle mineral shipments.

Shares on the Johannesburg Stock Exchange rose, with the blue-chip Top-40 index closing 1.53% higher.

South Africa's benchmark 2030 government bond was weaker, with the yield up 1.2 basis points to 9.760%.

(Reporting by Nellie Peyton and Bhargav Acharya; Editing by Tomasz Janowski and Alex Richardson)