At 1512 GMT, the rand traded at 18.1550 to the dollar, down 0.28% from its Friday close.
The U.S. currency was last down 0.18% against a basket of rivals.
The lack of risk appetite for the rand is a response "to high impact data this week that will set the tone for next week's Fed rate decision - an announcement that will likely shape the (South African Reserve Bank's) reaction", DailyFX analyst Warren Venketas told Reuters.
Investors will be looking at the U.S. GDP quarterly growth rate and core Personal Consumption Expenditures (PCE) index data due later this week for clues on the Fed's future path.
South Africa marks Freedom Day on Thursday, and with the following Monday another public holiday - Workers' Day - many local traders will be away from their desks from Wednesday's market close until next Tuesday.
The risk-sensitive rand often takes its cue from global factors like the outlook for U.S. monetary policy in the absence of major local drivers.
On global markets, the focus will be on a slew of central bank policy meetings that could signal how soon the steep increases in interest rates globally might come to an end.
"The South African economy will find it difficult to cope with a sustained aggressive hiking cycle from the U.S.," Venketas added.
"The next few weeks will be crucial for not just the local currency but the South African economy as a whole."
Shares on the Johannesburg Stock Exchange gained slightly, with both the broader all-share index and the blue-chip Top-40 index ending over 0.2% higher.
The government's benchmark 2030 bond was weaker, with the yield up 6 basis points at 10.180%.
(Reporting by Tannur Anders and Alexander Winning; Editing by Bhargav Acharya)
