At 1640 GMT, the rand traded at 18.6400 against the dollar, about 1.7% weaker than its previous close.
The dollar was up about 0.27% against a basket of major currencies.
There were no major South African economic data releases on Tuesday, leaving the rand to take its cues from global drivers.
Investors are keenly focused on Wednesday's U.S. consumer inflation report after Federal Reserve chair Jerome Powell said last week that policy decisions will be "driven by incoming data," while signalling a likely pause in the rate hiking cycle.
The rand has underperformed relative to emerging market peers this year as a power crisis showed no sign of abating and investor sentiment has been sapped by the country's "greylisting" by international financial crime watchdog the Financial Action Task Force.
The currency is down more than 7% against the dollar year-to-date.
On the stock market, the blue-chip index of top 40 companies and the broader all-share index ended down 1%.
South Africa's benchmark 2030 government bond was slightly weaker, with the yield up 3 basis points at 10.360%.
(Reporting by Alexander Winning and Nellie Peyton; Editing by Sherry Jacob-Phillips and Angus MacSwan)
