At 1532 GMT, the rand traded at 17.3400 against the U.S. dollar, 1.14% weaker than its previous close.
Eleven of the 20 economists polled by Reuters predicted the South African Reserve Bank would raise rates by 50 basis points to 7.50% at its upcoming rate-setting announcement on Jan. 26.
Most economists saw no further rate hikes after next week, forecasting the end of a tightening cycle that began in November 2021.
Recent economic data in Africa's most industrialised nation have been mixed, with weak November mining numbers released this week, followed by in-line December inflation figures and better-than-expected November retail sales.
On the stock market, the Top-40 index ended 0.58% lower and the broader all-share index dropped 0.45%.
However, Woolworths was up almost 5% after South African food and fashion retailer raised its profit growth forecast, saying it now expected half-year earnings to jump as much as 80% on strong Black Friday sales and festive demand.
The government's benchmark 2030 bond was weaker in afternoon deals, with the yield up 8.5 basis points to 9.740%.
(Reporting by Alexander Winning and Anait Miridzhanian; Editing by Jamie Freed and Toby Chopra)
