At 0645 GMT the rand was 0.39 percent firmer at 12.6300 per dollar compared to Monday's low of 12.8950, its weakest level since December.

"The dollar is overbought and a correction phase is imminent in our opinion," said analysts at Nedbank in a note.

The greenback retreated from five-month highs and US Treasuries also softened from seven-year highs, allowing some reprieve for emerging market currencies which have been battered by the surge in US assets.

South Africa's central bank announces its decision on lending rates on Thursday while ratings firms Fitch and Standard & Poor's are set to take ratings action on Friday.

The Reserve Bank (SARB) is expected to keep interest rates unchanged at 6.5 percent at Thursday's meeting, by all 25 economists surveyed by Reuters last week.

Bonds were also firmer with the yield on the benchmark paper due in 2026 down 5.5 basis points to 8.62 percent.

Stocks were due to open lower when trade commences at 0700 GMT, with the JSE's Top-40 futures index down 0.34 percent.